ENGINEERING LIBRARY 
 
Cornell University Library 
 QE 111.A13 
 
 First and second annual report of progre 
 
 3 1924 003 949 116 
 
Cornell University 
 Library 
 
 The original of tiiis book is in 
 tine Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924003949116 
 
FIRST AND SECOND ANNUAL REPORT 
 
 OF PEOGBESS BY THE 
 
 STATE •frBeiOGIST 
 
 AHD THE 
 
 ASSISTANT AND CHEMIST 
 
 ON THE GEOLOGICAL SURVEY OF 
 
 THE STA.TE OF lO^^A. 
 
 TOGBTHEB "WITH THE SUBSTANCE OF 
 
 POPULAR LETTERS 
 
 CONTKIBCTED TO THE NE"W"SPAPBES OF THE STATE DURING THE YEARS 
 AND 1867, IN AOCOHDANOE WITH LAW" ; ALSO EXTRACTS ORIGINALLY 
 CONTRIBUTED TO SOIBNTIFIG JOURNALS AS A PART OF THE 
 "WORK OP THE SURVEY. 
 
 DES MOINES : 
 
 V. "W. PALMER, STATE PRINTKB, 
 
 1868. 
 
UNlVERSilY,' 
 JBRARY 
 
GEOLOGICAL SUEYEY. 
 
 AN ACT providing for the completion of the Geological Snrvey of tlie State of Iowa.* 
 Section 1. Be tt enacted iy the General Assembly of the State of Iowa, That 
 for the purpose of completing the Geological Survey of the State, Charles A. 
 White, of Johnson county, is hereby appointed State Geologist, and shall hold 
 his office for the term of two years, or until his successor is appointed. 
 
 Sec. 3. The State Geologist shall he authorized to appoint a competent assist- 
 ant, and also a skillful analytical and experimental Chemist, who shall report to 
 the State Geologist the analysis of such soils, rocks, coals, ores and other mineral 
 substances, as he may submit to him for that purpose. He shall also have power 
 to employ such further assistance as he may deem necessary to prosecute promptly 
 and efficiently ihe field-work connected with the survey. All persons employed 
 by him shall be under his direction, and subject to removal by him. All the 
 specimens of minerals, fossils, rocks, soils, coals, ores or other geological .or min- 
 eral substances of any value or interest to either the practical or amateur geolo- 
 gist, and any drawings or sketches of the same obtained or made by said State 
 Geologist, as well as the copy -right of the reports and all books printed there- 
 from, shall belong to the State, and no specimen copy, draft or part of the same 
 shall be given away or sold, or permitted to be carried away contrary to the pro- 
 visions of this Act ; and the State Geologist, or any of his assistants or employes, 
 or any other person, who shall violate any provision of this section, shall be 
 deemed guilty of a misdemeanor. 
 
 Sec. 3. It shall be the duty of the State Geologist and his assistants to carry 
 on, with as much expedition as practicable, the Geological and Minei;alogical 
 Survey of the State, including observations and examinations of Ihe soil for 
 agricultural purposes. He may also include in hia report such matters as per- 
 tain to physical geography, and such other matters as properly and usually 
 pertain to a survey of this kind ; it being expressly required of the State Geologist 
 and his assistants, that these duties be performed in such a manner as to give to 
 the people of the State the greatest amount of practical information in relation 
 to its resources. 
 
 Sec. 4, It shall be the duty of the State Geologist, on or before the first Monday 
 of January of each year, to prepare a report of said survey and its progress, ac- 
 companied by such maps and drawings as may be necessary to illustrate the same 
 and transmit them to the Governor, who shall lay a copy of such reports before 
 
 * Dztiact of Cliapter 73, Laws of the Elcyenth General Assembly. 
 
4 REPORT OF STATE GEOLOGIST. 
 
 the General Assembly. That the Geologist shall, as far as practicable, use such 
 words in his reports as are in common use, and that he shall accompany each 
 volume of his reports with a glossary. It shall also be his duty to prepare, from 
 time to lime during the progress of the survey, communications for publication 
 in the newspapers of the Slate (provided it shall be done without expense to the 
 State), embodying such information in reference to the character and quality of 
 the soil, deposits of coal, minerals and other valuable substances, as he may deem 
 of general interest and importance to the public. 
 
 Sbc. 5. It shall be the duty of the State Geologist to cause collections to be 
 made of rocks, soils, fossils, coals, ores ond other mineral substances discovered 
 or examined, which shall be disposed of as follows, to- wit : All rare specimens, 
 of which duplicates can not be found and all specimens from which descriptions 
 or illustrations are drawn for publication, shall be deposited in the cabinet of the 
 State University. A full series of the best of such specimens as more particularly 
 exemplify the economic geology of the State, shall be deposited in the cabinet of 
 the State Agricultural College. All other specimens shall be distributed to the 
 cabinets of all other organized institutions of learning in the State, giving prefer- 
 ence to the State University, the State Agricultural College, and the Medical 
 College at Keokuk. 
 
FIRST ANNUAL HEPOET 
 
 OP 
 
 CHAELES A. WHITE, M. D., STATE GEOLOGIST. 
 
 Iowa City, January 3, 1867. 
 To Sis Mccelleney, William M. Stone, Oovernor of Iowa : 
 
 SiK: In accordance with section four of chapter seventy -three of the laws 
 of the Eleventh General Assembly, I herewith submit to you my first annual 
 report of the progress of the Geological Survey of the State. Upon your appro- 
 val of the law referred to, March 80th, 1866,1 repaired to the capital for the 
 purpose of being legally qualified, and then entered immediately upon the duties 
 of my office. I appointed Mr. Chandler Childs, of Dubuque, as my field - assistant, 
 and Prof. Gustavus Hinrichs, of the State University, as chemist of the survey. 
 The first work done was a review of the older rocks of the eastern half of the 
 State,' from the oldest fossiliferous formations to the sub -carboniferous limestones 
 inclusive. This was accomplished by visiting various localities in company with 
 my field assistant, making measurements and collecting specimens for study, and 
 for the State Cabinet. 
 
 The principal object of this review was that we might obtain as complete a 
 knowledge as possible of the fall series of the formations of the State, in their 
 regular order, and thus enable us to study with greater precision the coal^bearing 
 strata, to which it is proposed to devote the greater part of each season's labor. 
 After accomplishing this, it was found necessary to make some comparative 
 examinations of the coal ■ deposits of the neighboring States, and also along the 
 northern border of our own coal-field. Then preparing an outfit consisting of a 
 pair of horses with a covered wagon, tent and other necessary articles, we pro- 
 ceeded to the southwestern part of the State by the way of the southern tier of 
 counties, and subsequently carried on careful examinations over the three south- 
 ern tiers, from the Missouri River to those counties which border the valley of 
 the Des Moines River, comprising Decatur, Ringgold, Taylor, Page, Fremont, 
 Mills, Pottawattamie, Cass, Montgomery, Adams, Adair, Union, Madison, and 
 parts of Clarke, Wayne and Appanoose counties. It was considered of great 
 importance that we should know the extent of our coal -field in that direction, as 
 well as just to the people of the western part of the State, because the examina- 
 tions of the previous survey did not reach them. 
 
Q REPORT OF STATE GEOLOGIST. 
 
 Wiahing to accomplish all that was possible for the development of fuel for 
 our State, early in September last I sent my assistant to the counties of Franklin, 
 Wright, Oerro Gordo, Hancock, Worth and Winnebago, for the purpose of examin- 
 ing that region for deposits of peat, while I continued the examinations in relation 
 to the coal-field. Peat will no doubt be found in large quantities in other parts 
 of the State, but for reasons suggested by the character of the surface in relation 
 to the streams of that region, climate, &c., it was thought to be one of the most 
 favorable for present investigations of this kind; beside which, it is entirely 
 beyond the limits of the coal-field, and within it no other fuel except wood may 
 be expected. 
 
 My instructions to my assistant were that he should report to me at the end of 
 every week, that I might give the results to the people through the public press 
 as soon as they were ascertained, but I regret to say that I have received no report 
 from him for more than three months, in consequence of which I have been 
 obliged remo-ve him, and have appointed Mr. Orestes H. St. John, of Waterloo, 
 Black Hawk county, in his stead. I continued my field- work until the 10th of 
 November last, at which time the weather became too inclement to prosecute it 
 further for the present season. 
 
 The more prominent results of the field - work may be briefly stated as follows : 
 That formation known among geologists as the coal - measures consists in our 
 State of a succession of strata of sandstone, limestone, sandy, clayey and car- 
 bonaceous shales, marls and coal ; and is divided into the upper and lower 
 series. The lower series only is found along eastward and northward of the Des 
 Moines River Valley, and consists principally of shales and sandstone, together 
 with the coal. Very little limestone is found associated with them, and that is 
 always more or less impure. This series contains all the productive coal-beds, 
 and consequently furnishes nearly all the coal now obtained in the State. The 
 upper series consists principally of limestone, with some fine -grained sandstone 
 and marly shale. It is not known to exist at all northward and eastward of the 
 Des Moines River, but to the southward and westward of that river it reaches a 
 maximum development of one hundred and seventy ■ five leet in tbickness. There 
 are at least two carbonaceous horizons in this series, one of which embraces the 
 only bed of coal yet found iu tbe western part of the State. The other is of 
 limited extent, usually showing a thin seam of highly carbonaceous matter, but 
 in the form of shale, and entirely worthless. The bed of coal referred to finds 
 its greatest development along the valleys of the Nodaways, in the counties of 
 Adams, Taylor and Page, and is there, at most, only twenty inches in thickness. 
 Its horizon has been recognized in most of the counties referred to, but the coal- 
 bed is found to diminish in thickness to the eastward, westward and southward, 
 so that in these directions little is seen except a thin band of carbonaceous matter 
 of no economic value, as its representative. The strata of this series are nearly 
 horizontal in an easterly and westerly direction, so that one, in passing from 
 Madison or Clark to Fremont or Pottawatamie counties, would be, in geological 
 language, constantly upon the line of strike, the dip of all the strata being to the 
 southward, and nearly coincident with the fall of the streams. 
 
REPORT OP STATE GEOLOGIST. 7 
 
 lu all that region of the south-western part of the State, comprising the thirteen 
 or fourteen full counties, named, the only accessible rocks are those of the upper 
 coal - measure series, which in the deeper valleys of Mailison county at least, I 
 found resting upon the upper part of the lower series, as at present understood; 
 eastward from which point, the upper series rapidly disappears, and the lower, 
 with its coal, becomes accessible. 
 
 This determination of the relative position of the strata of the western and 
 central parts of the State, which was first made known by my labors during the 
 past season, becomes a matter of very great economic interest to the people, for 
 upon it depends the direction of intelligent effort in future investigations for coal. 
 It is known that the upper series, in the region referred to, contains too little coal 
 for the uses of the inhabitants, tut it is not contrary to any known principles of 
 geology to expect to find the lower aeries, with its coal - beds, extending beneath the upper 
 series to the western part of the State, by sinking shafts of not impracticable depth down 
 to them. 
 
 During the progress of the field-work, I wrote frequent articles for the public 
 press, explanatory of its results, in accordance with the law. I herewith transmit 
 to you printed copies of the same, thirty- three in number, as apart of my report. 
 
 The desire on the part of the principal newspapers of the State to obtain these 
 communications has been so great that I have prepared from two to four manu- 
 script copies of each one of them, and sent thera simultaneously to as many news- 
 paper oflSces for publication. These have again been copied into other papers of 
 the State ; in addition to which the leading newspapers of the neighboring States 
 have frequently made copious extracts therefrom. 
 
 A large quantity of material has been collected, consisting of minerals, fossils, 
 soils, clays, fuels, samples of building-rocks, mineral waters, &c., &o. I have not 
 yet had time to fully investigate and arrange these collections, but they are known 
 not only to comprise much that the State Cabinet has never before contained, but 
 also a number of species not beforS found in the West, some of which are yet new 
 to science. My first care will be to label and arrange these collections in such a 
 manner that a knowledge of their ownership, geological position and location can 
 not be lost. Those of which it is desirable to have chemical analyses and investi- 
 gations made, are in the hands of the chemist. By reference to his report, here- 
 with annexed, it will be seen that he has entered upon his work with an earnest- 
 ness and care which give promise of the most satisfactory results. It is proposed 
 to devote a considerable part of the time during the winter months to the critical 
 investigation of these collections, and whenever it may be necessary to secure to 
 the State the credit of priority in those labors, the results will be published in 
 some of the scientific periodicals of the country in advance of my final report. 
 After this has been done, the specimens will be distributed according to law. 
 
 The Faculty of the State University have generously given me the free and 
 exclusive use of their large cabinet roorn for an oflice, and in which to study and 
 arrange the collections. The railroad -companies of the State give me free access 
 to the records of theif surveys, and oifer me all facilities for investigation that can 
 
8 REPORT OF STATE GEOLOGIST. 
 
 be desired. I find the people much interested in the progress of the work, and 
 everywhere kind and obliging. As soon as the weather will admit of field 
 operations in the Spring, it is proposed to take up that work where it was left at 
 the close of the season just passed, giving especial attention to the subjects of 
 coal and peat. 
 
 All of which is respectfully submitted. 
 
 CHARLES A. "WHITE, 
 
 Statt Qeologisi. 
 
EEPOET OF THE CHEMIST. 
 
 To Dr. C. a. White, State Geologist : 
 
 Sir : I herewith submit the following as a report of progress of the chemical 
 investigations connected with the survey : Up to date, two hundred and thirty - 
 two numbers of specimens have been received at the laboratory for examination ; 
 many of these numbers representing duplicates. The material thus accumulated 
 by you during the first season of the survey, is not only large in amount, but also 
 of great intrinsic value for the scientific and economic mineralogy of the State. 
 The specimens have all been labeled by numbers, which numbers are here used 
 to designate them. 
 
 I. MINERAL WATERS 
 
 Have been received from Mt. Pleasant (114), Ottumwa (121), Bloomfield (34), and 
 near Salt Creek, Davis county, (73); also, water and its peculiar sediment from 
 the Missouri Eiver (187.) Of these, the first four have been analyzed. These 
 analyses, together with one of a spring water made for the Iowa Hospital for the 
 Insane, constitute the only analyses yet made of the waters of the State. 
 
 II. ROCKS AND SOILS. 
 
 A considerable number have been received. No. 8 from Burlington, Nos. 77 
 and 78 from Madison county, and No. 79 from A'dair county, have been examined; 
 No. 10 from Clarke's quarry, near Iowa City, has been analyzed, and found to owe 
 its dark color to phosphate of protoxide of iron. As phosphates are especially 
 fertilizing, it will be important to investigate other rocks in the same direction. 
 Of soils, none have been as yet analyzed ; such analysis can be more expeditiously 
 and accurately made when a larger number of samples shall have been collected. 
 
 in. COAL AND PEAT. 
 
 The analyses of coals made by Prof. Whitney, the former State Chemist, have 
 been discussed. These analyses plainly show, that the combustible part in the 
 Iowa coals is very nearly uniform, consisting of forty- five per cent of bitumen 
 and fifty - five per cent of fixed carbon ; the great variation observed in the 
 difierent coals analyzed being due to the varying proportions of ashes and 
 moisture associated with the combustible part. The theoretical bearing of these 
 results upon the formation of coal is apparent. Their practical importance is 
 also very plain, for a determination of the amount of ashes of the dried coal is 
 2 
 
10 
 
 REPORT OF STATE GEOLOGIST. 
 
 equivalent to the more elaborate analysis. It will be important to make many 
 further analyses, in order to asoerl.ain whether the same law will hold ,good for 
 all Iowa coals. 
 
 Of new analyses, the following have been majle: (124) cannel coal from Mt. 
 Pleasant, Henry county; (136) coal from Bentonsport, Van Buren county ; (123) 
 peat from Solon, Johnson County; (125) peat from Mason City, Cerro Gordo 
 county ; (126) the same condensed. 
 
 IV. MINBRALS. 
 
 \ 
 
 Gelestine. The specimens brought by you from Fort Dodge proved to be sul- 
 phate of Btrontia or Gelestine, which according to Whitney has not before been 
 recognized in any locality west of Ohio.— Wiseorisin Repm% page 113. 
 
 Gypsum. Nos. 9, 29 and 35, from Dubuque; No. 23 from Fort Dodge; the 
 latter white, and almost chemically pure. 
 
 Barytes or Heavy Spar. Nos. 4 and 5, from Bremer county ; No. 7, from Decatur 
 county; Nos. 40, 42, and others, from Dubuque. 
 
 Epsomite or Sul/phate of Magnesia. (Nos. 167 and 168) discovered by you some 
 years ago near Burlington. 
 
 Gale spar in many varieties, as No. 16. Dog-tooth spar : geodes from "Waverly, 
 Bremer county ; No. 17, the same with Brown spar covering ; Nos. 33 and 48, 
 Spars, and other varieties from Dubuque; Nos. 3 and 8, Anfhraconite in fine 
 columnar masses from Waverly, Bremer county. Nos. 60 and other, Rock Milk, 
 from Dubuque; 177, Dog-tooth spar, from Iowa Falls. 
 
 Manganese, has been found in dendrites on slabs from Anamosa, (Nos. 13 and 
 14) on calcareous spars from Waverly, (No. 17) and Iowa Falls, (177.) It has also 
 been detected as Wad (60, 61, 67) and Pyrolusite (47) from Dubuque. 
 
 Zinc, lead, and iron ores have been received and determined, but not yet 
 analyzed. 
 
 The fine collection of geodes from Bentonsport has been partially investigated. 
 The full investigation of this mineralogioal treasure will require much further 
 labor. 
 
 The specimen No. 121 from Red Rock, Marion county, will probably prove to 
 be a new mineral species. 
 
 A fall analysis has been made of clay from Iowa Falls; No, 20 is a remarkably 
 pure marly clay; No. 21, a fire clay containing some ferruginous sand, and well 
 adapted to various kinds of fine pottery. 
 
 From the work already done, both in regard to the material collected in the 
 field, and the study in the laboratory, I may venture to predict that your final 
 report v/ill contain a chapter on the scientific and economic mineralogy of Iowa, 
 consisting of the results of investigations, hitherto only barely commenced. 
 
 GUSTAYUS HINRICHS, 
 OTismiat. 
 
POPULAR LETTERS 
 
 THE STATE GEOLOGIST 
 
 FOR 1866. 
 
USTTRO DUO TORY. 
 
 By reference to the law of the Eleventh General Assembly, on the opening 
 page, it will be seen that provision vpaa made for the publication of newspaper 
 reports of the observations made during the progress of the State Geological 
 Survey. 
 
 This provision, although a novel feature of law relating to a;eological surveys, 
 and adding largely to the labors of those in charge, has nevertheless become 
 very popular with the people of Iowa daring the last two years, and it is believed 
 also that they have been much benefitted by its fulfillment. Instead of making 
 records of observations to be filed away in the office until a future General 
 Assembly should provide for their publication, and when, through lapse of 
 time, many opportunities to take practical advantage of such information 
 would have been lost to our citizens, these results have been made immedi- 
 ately available to all by the frequent publication of letters from the field and 
 from the office, in the various State newspapers. 
 
 These letters were almost always written in " manifold," and one copy inva- 
 riably sent to the newspaper of the neighborhood where the observations recorded 
 were made ; and the others, from two to ten in number, were sent simultaneously 
 to other papers in various parts of the State, amounting m all to between forty- 
 five and fifty, in all of which they have appeared as original matter. 
 
 Many of those letters were written by the light of the camp - lantern, after the 
 field - labors of the day were over, and were consequently unsatisfactory to the 
 writer, because it was inevitable that minor errors should be admitted into com- 
 munications made before the observations were complete. Again, many of them 
 having been written for different readers, while the subjects of each were similar, 
 it was often necessary to repeat in one what had already been written in another ; 
 for it was the aim of the writer to present the information contained in those 
 letters in such a form as to be readily understood by all, and also to present such 
 other matter as should be attractive to the general readers, and thus awaken 
 popoular interest in geological subjects. 
 
 By request of the Committee of the Senate who ordered the printing, such 
 errors and repetitions have, to a great extent at least, been excluded, so that 
 what is said of many of the counties appears somewhat changed from the form 
 in which it originally appeared in the newspapers. An exception to the rule of 
 excluding repetitions is made in favor of whatj has been said in relation to the 
 growth of forest trees. This is a matter of so much importance that loo much 
 
l^ REPORT OF STATS GEOLOGIST. 
 
 cannot be said to encourage the people to plant largely of all kinds of our native 
 trees, which it is now known will grow as thriftily upon prairie soil as any where 
 else. It is to be regretted that time would not allow the arrangement of the mat- 
 ter contained in those letters according to the various subjects discussed. Instead 
 of this, the subject matter is left in the order of time in wliich the observations 
 were made, or according with the progress of the work. 
 
 The scientific reader will thus understand why it is that official reports of the 
 survey are presented in this unusual form, but he must not for a moment suppose 
 that any scientific principle will be sacrificed to popular prejudice or preference. 
 All matters that are more abstractly scientific in their character are receiving 
 their full share of attention as the work progresses, and several papers of this 
 character have already been published in various scientific journals, two of which 
 are herein re - printed. It is of course expected that a comprehensive final report 
 will be published in standard form, in addition to. these preliminary papers and 
 reports. 
 
 Considering the fact that only a few years ago geology was not made a part of 
 even a liberal education, it is thought advisable to give a few words of popular 
 explanation of its principles so far as relates to the geological structure of our 
 State. All the rock formations of Iowa are stratified ; that is, they have without 
 doubt been formed at the bottom of the sea in more or less regular layers, and 
 now, since their elevation from the sea, they extend, as it were, in broad sheets, 
 lying the one above the other, beneath the whole surface. 
 
 In Iowa the order of superposition of the formations is comparatively simple, 
 because no great disturbance of the strata has taken place here, as has been the 
 case in some other regions. The characters and composition of our rocks are 
 various, being limestone, sandstone, magnesian liraos'one, shale, clay, coal, &c., 
 for whether hard or soft, geologists call them all rocks. Even the coal, since it 
 lies in beds parallel with beds of rock, is practically itself a stratified rock, 
 whether the theory of its marine origin advocated by the chemist in his letters is 
 the correct one, or not. 
 
 Nearly all stratified rocks are found to contain fossil remains, which in ours are 
 principally shells and corals of many kinds ; and by the study of these, geologists 
 find that certain sets of strata are characterized by certain fossils that are found in 
 them, and nowhere else. It is this which gives collections of fossils their great 
 value, for without the information they thus afford they would be of no more 
 value than broken crockery. By studying the" fossils of all the formations we are 
 able to determine the relative position of any one of them, even if but a small 
 part of a single one is found exposed ; for this relation, when once ascertained, is 
 found in all cases to be constant and reliable. The strata thus studied are divided 
 into contiguous groups and variously named in an order indicative of their rela- 
 tive ages, as Lower Silurian, Upper Silurian, Devonian, Carboniferous, &c.- the 
 lowest in the series being the oldest, and the others successively of later and later 
 origin. The strata of our State do not now lie in a perfectly horizontal position. 
 If they did we could find little more than the upper ones, but by a change in the 
 
REPORT OF STATE GEOLOGIST. Xg 
 
 surface which probably went on slowly while they were being deposited, they 
 have been elevated so that their slightly upturned edges come to the surface as 
 one goes from the southwest to the northeastern corner of the State, where the 
 oldest, and geologically tlie lowest are fuiind. It will thus be seen that the plane 
 of any of the geological formations beneath the surface have no necessary relation 
 to the plane of that general surface. For instance, of the rocks exposed along 
 the Mississippi river, those in Alamakee and Clayton counties are the lowest 
 geologically, although topographically the highest, and as one goes down the Mis- 
 sissippi, he goes wp in the geological scale. 
 
 Through the politeness of Dr. Mark Ranney, Superintendent of the State Hos- 
 pital for the Insane at Mount Pleasant, Henry county, who presented a series of 
 carefully preserved specimens of the borings of their Artesian well, we obtained 
 very satisfactory proof of this order of superposition of the strata. 
 
 An examination of these, enabled us to identify, by their lithological characters, 
 the formations which the drill passed through, because we were previously 
 acquainted with those^ characters, having studied the same rocks as they sucoess- 
 iyely make their appearance at the surface northward. 
 
 At the depth of 1125 feet, the bottom of the boring, we identified the rock as 
 the same as that which forms the tops of the hills at Dubuque, more than a 
 hundred miles northward ; and if the boring had been continued, the drill would 
 have reached those rocks which come to the surface still further to the northward. 
 The record of that boring says that the drill passed through no coal. This could 
 have been predicted, because the first rocks pierced by the' drill were those of the 
 sub- carboniferous limestone which is found to form the floor, so to ppeak, of the 
 formation which contains the coal. If they had commenced this boring in 
 Jefferson, the next county westward, they would doubtless have passed through 
 at least a portion of the coal-measure strata before reaching the limestone upon 
 which they started at Mt. Pleasant. If they had.commenced their boring in the 
 southwestern part of the State they would have been obliged to pierce many 
 hundred feet of barren and probably also productive coal-measure strata before 
 their drill reached the limestone which is at the surface in Henry county where 
 they began to bore. Prom what has been said it will be seen that the general dip 
 of all the formations is to the southward, although it is so slight that is not 
 perceptible to the eye ; so that the oldest formation is in the northeast corner of 
 the State, and the newest in the southwest corner. This is true with one excep- 
 tion. A formation newer than all the others, the Cretaceous, is known to occupy 
 a large area in the northwestern part of ihe State, where a large part at least, of 
 the other formations dip beneath it to the northwestward. 
 
 We have evidence which is admitted by all as conclusive, that after all the 
 stratified rocks had been formed, there was a time when the whole northern 
 hemisphere, as far south at least, as the Ohio river in our country, was covered 
 with ice, as Northern Greenland is at the present time. The ice is believed to 
 have existed as an almost continuous glacier, moving with an infinitely slow but 
 constant motion to the southward, grinding up in its passage the surface portions 
 
16 
 
 REPORT OF STATE GEOLOGIST. 
 
 of the formations upon which it rested into the fine material that now constitutes 
 our soil and subsoil, and which now covers those formations lilie a mantle, so that 
 we seldom see them in place except when they have been bared by the streams 
 while they were cutting out their own valleys. The granite boulders and 
 pebbles so common in all parts of the State were brought down from the north 
 by the same means, for we have no other granitic rocks within our borders, and 
 these with the material ground up by the glaciers were mixed into a heterogenous 
 mass which now occupies the surface every where, and is called "drift" by 
 n-eologists. Lumps of copper, doubtless from the Lake Superior region, and 
 masses of lead ore probably from the Dubuque lead region are sometimes found 
 in the drift of the different parts of the State, where they happened to be released 
 by the melting ice as the glacial epoch passed away. In Northern Iowa also, 
 quite beyond the limits of our coal - field, lumps of coal have been found in the 
 drift which the inhabitants sometimes regard as an indication of the existence in 
 their neighborhood of a bed of coal. But these lumps were probably brought 
 down by the ice from a thin bed of coal which is believed to exist in Southern 
 Minnesota, and which belongs to rocks of Cretaceous age, and consequently 
 having no connection with the Iowa coal-field. The subject of the drift forma- 
 tion will be found further discussed in the following pages under the heads of 
 "Drift phenomena in Southern Iowa," and " Lakes of Iowa, past and present." 
 
 The term " coal-measures " is one introduced from England, and simply means 
 the formation which contains the coal. It was once believed that all the coal of 
 the earth is contained in the formation of that particular geological age, but sab- 
 sequent investigation has proved this view to have been incorrect. We have 
 now much evidence tending to prove that all the coal yet found in the far West, 
 as we in Iowa understand those words, is of much later origin than our own, 
 and with which ours has no connection by continuity of formations. 
 
 The coal-measures of Iowa are properly separable into upper, middle and lower 
 divisions. The first lies wholly to the southward and westward of the Des Moines 
 River, occupying the surface in the southwestern part of . the State over an area 
 equal in extent to that of the State of Vermont. The second doubtless underlies 
 the whole of the first, but it occupies the surface only aloi.g its northern and east- 
 ern borders, including the greater part of the region of the Raccoon Rivers, which 
 region is more particularly referred to in Mr. St. John's report, on another page. 
 The lower coal-measures occupy the surface of a large area, averaging some fifty 
 miles in width, and about one hundred and seventy- five miles in length, through 
 the middle of which the Des Moines River runs longitudinally in a southeasterly 
 direction, from a little above Ft, Dodge, nearly to Keokuk. Over nearly the 
 whole of this large surface coal may reasonably be sought for. To the northward 
 and eastward of it, it is useless to look for coal except in small " patches" or out- 
 liers. These are almost always unproductive of a workable bed of coal • the 
 large outlier extending from Muscatine nearly to Davenport being an exception. 
 To the southward and westward of this region it is believed that coal will be 
 found by sinking shafts to a greater or less depth. 
 
 The lower coal-measures contain all the heaviest beds of coal, and by far the 
 
REPORT OF STA.TE GEOLOGIST. 17 
 
 largest part to be found in the State. The middle measures contain some worka- 
 ble beds, but the upper series are believed to contain only one bed of coal, the 
 greatest thickness of which is only twenty inches. 
 
 The lower coal-measures are made up principally of sandstone, shales, clay and 
 coal, with very little limestone ; the middle, of similar materials, but has more 
 limestone, less sandstone, and less coal, while the upper coal - measures are com- 
 posed largely of limes'one, which in Madison county alone is found to reacli a 
 thickness of more than a hundred feet, beside the other strata exposed there. 
 
 The lower coal-measures disappear beneath the middle and upper measures to 
 the southward and westward, but we may confidently expect to reach the con- 
 . tinuation of those strata by sinking deep shafts in the western part of the State. 
 It is not absolutely certain that coal will be found in those strata when thev are 
 so reached, but when a similar condition of the strata are found to exist in 
 densely populated countries, capitalists do not hesitate to invest their money in 
 such enterprises, and the lime will doubtless come when it will be done in Western 
 Iowa. 
 
 However, since coal-beds are liable to thin out as the distance increases from any 
 given maximum point of development, and that all formations are expected to be 
 thinnest at their borders, it will be less hazardous as well as less expensive to 
 commence such enterprises in the valleys near the eastern or northern border of 
 the upper or unproductive coal-measures, say in the counties of Decatur, Clarke, 
 Madison and Adair; and if successful at those points it would encourage similar 
 enterprises still farther and farther to the westward. Yet we do not know that 
 the maximum development of the coal beds may not be to the westward of the 
 Des Moines river region. 
 
 People throughout the State very often ask the following questions by letter 
 and otherwise : What relative position does coal hold to limestone, sandstone or 
 other strata ? What is regarded as "coal - blossom," or a sure indication of the 
 presence of coal beneath the surface? The tern: "coal-blossom" is not used by 
 geologists, but those who use it appear to mean the presence of per oxide of iron, 
 or simple iron-rust in the water of springy places, and impregnating the earth 
 around where it issues. So far as that appearance is concerned it amounts only 
 to this : The strata associated with the coal, and also the coal itself, almost 
 invariably Qontaia more or less iron, which being oxidized passes out with the 
 water which finds its way over or through them. But while this is true, other 
 strata which have no possible connection with coal, also at times are found to 
 contain iron in a similar form, v? hich of course presents similar appearances at 
 the surface. 
 
 As to the relative position of coal-beds with other strata, the rule is that a bed 
 of clay, commonly called fire-clay, underlies a bed of coal, while a bed of shale, 
 often called soapstone by the people, almost always overlies it. Sometimes, how- 
 ever, sandstone, or even limestone, has been found to rest upon, or to underlie, a 
 bed of coal. 
 
 In the following pages, a limestone w ill bs referred to which underlies all the 
 3 
 
]^g REPORT OF STATE GEOLOGIST. 
 
 coal-measure strata, and beneath wbich it is useless to search for coal. Tliis is 
 the sub-carboniferous limestone, and is usually found to belong to that division 
 which geologists have named the St. Louis limestone, because the same formation 
 is well exposed near that city. It is by no means meant that limestone is never 
 found above the coal, f >r the upper coal - measures are largely composed of lime- 
 stone, and the general appearance of the rocli of these two limestone formations 
 is often almost identical, yet when one is acquainted with the fossils which char- 
 acterize each, he will know without hesitation whether a given exposure belongs 
 above or below the productive coal-measures. Since the lower coal-measures 
 contain almost no limestone, any such rock tound in the region occupied by that 
 formation, as for instance along the Des Moines River, may almost certainly be 
 referred to the sub -carboniferous formation ; because the streams, in cutting out 
 their own valleys, have bared the limestone after they had cut clear through the 
 coal -measure strata. From the fact that this limestone is so often exposed near 
 the streams which run through the region occupied by the lower coal -measures, 
 it is evident that no very deep mining will be requisite in that region, to reach all 
 the coal that exists there, because all the coal lying above the limestone will 
 usually be obtained by drifting into the edges of the. beds which crop out at the 
 sides of the valleys. Strictly speaking, there arc no indications that absolutely 
 prove the presence of coal beneath an}' given spot, but since coal-beds are known 
 to have very considerable extent beneath the surface, and to lie in nearly a uni- 
 form plane, one may often make very satisfactory calculations as to its presence 
 or absence. Thus, if a bed of coal is found cropping out in one side of a valley, 
 one may expect to find the same be i cropping out of the other side of it ; and if 
 a similar exposure should be found in another valley a few miles distant, it is 
 reasonable to suppose, In our coal-field at least, that the two exposures are parts 
 of the same bed, and that it is continuous beneath the whole intermediate space, 
 and further, that it maybe reached at an estimated di'pth by sinking a shaft down 
 to it from the high land between the two valleys. B-side this, it will be seen 
 from what has been said that the geologist is able to draw a line, at least appioxi- 
 mately, and say "beyond this line it is useless to explore for coal, while within it 
 there is a reasonable prospect of finding coal." 
 
 Mining in our State will always be mainly confined to coal, as will be seen by 
 reference to descriptions of the extent and rharacler of the coal-field on the follow- 
 ing pages. Next in importance comes the lead mines of Dubuque, which although 
 very important, occupy a very limited area. The present prospect that other 
 mineral substances will be found in paying quantities is not encouraging. Occa- 
 sional masses and small deposits of iron ore are often found, but none have yet 
 been discovered that will warrant the erection of a furnace, and even if it were 
 so, as soon as our northern and southern railroads are built, iron from the Iron 
 Mountain region in Missouri would doubtless be brought here more cheaply than 
 vre could manufacture it from our own scanty ores. 
 
 ArTHORSHIP. 
 
 The articles on "Surface Geology of the Middle Region of Western Iowa,' 
 
REPORT OF STATE GEOLOGIST. 19 
 
 "The Geology of the Raccoon River Region," and the report which bears his 
 name, are the work of the Assistant. The articles on "The Fuel of Iowa," 
 "Waters of Iowa," " Rocks of Iowa," " Valuation, composition, and proximate 
 analysis of coals," " Mineralogy of Iowa," together with the reports which bear 
 his name are the work of the Chemist. All the remaining matter is by the State 
 Geologist. As usual in such cases, each author is to be considered as responsible 
 for his own work. 
 
SURYEY OF COUNTIES. 
 
 BLACK HA.WK AND BREMER COUNTIES. 
 
 HYDRAULIC CEMENT. 
 
 In April of 1866, while making the examinations referred to in 
 the preceding report, a communication was sent to the Waterloo 
 Courier, which contained the following paragraphs : 
 
 " Throughout the northeastern portion of the State, the pre- 
 vailing character of nearly all the formations is magnesian lime- 
 stone, which character extends to the Devonian rocks of your 
 county, although the same formation in Johnson county, and else- 
 where in the State, is but very slightly magnesian. It is a well 
 known fact that rocks quite various in their chemical composition 
 will nevertheless make, when properly prepared, excellent hydraulic- 
 cement, and among the rocks from which this cement is prepared 
 are the very kinds of magnesian limestones which are found in the 
 northeastern portion of the State. Those of your own vicinity are 
 as well worthy of a trial for this result as any known to me in the 
 Mississippi Valley, and specimens were collected from various quar- 
 ries in your region with a view to having them analyzed and tested. 
 It must be remarked, however, that the only reliable tests are those 
 which may be made at an ordinary lime - kiln, by properly burning 
 the rock, and afterward grinding it very fine, and then by practical 
 trial of the substance produced. When it has been determined that 
 any rock will make the cement desired, the necessary skill can be 
 readily acquired by any one for producing it in any quantity. 
 
 "It is the intention of Mr. Mclsaac, of Waterloo, to make some 
 practical tests of the magnesian limestones of your vicinity to which 
 I have referred." 
 
 Within the last two months, Mr. Mclsaac informed me that although 
 
REPORT OF STATE GEOLOGIST. 21 
 
 a press of business had prevented him from making the proper experi- 
 ments, Mr. Robert B. Brown, of Waverly, Bremer county, had been 
 conducting a series of experiments with evident success. A short 
 time afterward Mr. St. John called on Mr. Brown, and obtained for 
 the State collections a full suite of specimens illustrating his experi- 
 ments, and from which it seems almost certain that he is just upon 
 the eve of complete success in the manufacture of hydraulic cement 
 of excellent quality, although the practical test of its use must be 
 made before such a decision can be given. In view of the energy 
 with which Mr. Brown is conducting his experiments, we may hope 
 to know the full result before the close of the present year. 
 
 Similar references were made to the magnesian limestones in the 
 vicinity of Cedar Falls, in a communication about the same time to 
 the Osdar Falls Gazette. 
 
 Very little time was spent in Black Hawk county, but it was seen 
 to be well supplied with building -stone, brick -clays, forest -wood, 
 excellent water, almost unlimited water-power, and as to its soil, it 
 is already high praise when it is said that it is a part of the Valley 
 of the Cedar. 
 
 HARDIN COUJMTY. 
 
 Crossing from the Cedar to the Iowa river, the extreme northeast- 
 ern corner of the coal-field was visited, in the vicinity of Bldora, 
 Hardin county. Commencing examinations at Iowa Falls in the 
 northern part of the county, the following was soon after communi- 
 cated to the Iowa Falls Sentinel : 
 
 The rocks exposed along the river near Iowa Falls belong to the 
 lower portion of the sub - carboniferous group, and are consequently 
 older than, and below the coal. Standing at the mill in the village 
 and looking across the river, you will see that the strata dip from 
 that point both eastward and westward, their most elevated point, 
 which geologists call an anti - clinal axis, being just where you stand. 
 The eastward dip does not probably extend far, before the strata 
 gradually rise again. The westward dip is so great that a little above 
 Talbott's mill, three miles from town, all the strata which you can see 
 in the village have passed nearly out of sight beneath the river, and 
 begin there to receive the coal - measure deposits upon them, but that 
 
22 REPORT OF STATE GEOLOGIST. 
 
 any coal exists among them, remains to be decided by boring or 
 digging. My opportunity for examining this locality was not satis- 
 factory, but judging from the fact that it is just upon the border of 
 the coal - field, and in a local depression, since the Iowa Falls strata 
 rise and appear again at Alden, the prospects for obtaining coal in 
 paying quantities at or near Talbott's mill, are not believed to be 
 promising. 
 
 The close proximity of the Eldora coal, however, and the existence 
 of the large body of timber westward of Iowa Falls, give you a great 
 advantage over many other towns of the State, in a plentiful supply 
 of fuel. Considering the large tracts of country on which no stone, 
 certainly no limestone, is to be seen, you possess another great 
 advantage in the large exposures of excellent limestone, which, figu- 
 ratively speaking, nature seems to have lifted out of the earth just 
 at that point for your especial benefit, but in doing this she deprived 
 you of the coal which was bestowed upon your neighbors of the 
 southern part of the county. All the strata exposed along the river 
 in the village are composed of a good and comparatively pure lime- 
 stone, all of which will make good lime, and many of which furnish 
 excellent stone for dressing. The rough, fragmentary stone of a 
 yellowish color, seen in the hills around, and to the southeastward of 
 the village, are magnesian limestone, although they look like, and are 
 frequently called sandstone. This stone is probably useless except 
 for the roughest masonry, but since good stone is so abundant, this is 
 not needed. 
 
 The following is a part of a communication to the Eldora Ledger, 
 communicated June 6, 1866 : 
 
 The rocks exposed along the river at Iowa Falls, as do also the 
 rough fragmentary layers in the hills around, and southeastward of 
 the village, which overlie them, all dip to the southward, in which 
 direction the lower ones soon disappear, but the upper portion, which 
 is highly magnesian and at Hardin City, contains considerable iron 
 and some sand, can be traced as far as the village of Steamboat 
 Rock, where they suddenly disappear and the coal-measure sandstone 
 as suddenly makes its appearance. 
 
 Within a mile of this first appearance of the sandstone, it presents 
 a perpendicular front of some seventy - five feet on the left bank 
 
REPOET OP STATE GEOLOGIST. 23 
 
 of the Iowa river ; and within two miles on a straight line from the 
 locality where the coal - measure rocks first appear, they reach a 
 development of nearly or quite two hundred feet in thickness, as 
 seen in the hill, and by the boring at Buckner's coal mine. This is 
 a very remarkable development of strata so near the well defined 
 border of the coal-field, and causes some hesitation in giving a 
 positive opinion as to the relative position of the underlying rocks 
 of the immediate neighborhood, before a very careful examination is 
 made. And there are also evidences of a slight local and irregular 
 dip of the whole region, to the southward. Just at Buckner's mine 
 there seems to be a local longitudinal depression, extending thence a 
 little east of south, so t^iat the strata probably dip slightly both 
 east and west toward the axis of it. Along this axis the bed of coal 
 appears to bo below the level of the river, but elsewhere it is 
 doubtless above it. 
 
 Exposures of coal-measure strata were observed in the region 
 surrounding Buckner's mine indicating that they underlie a surface 
 of some two square miles, and doubtless more, but how far the bed 
 of coal now worked extends, and what is its thickness, in continua- 
 tion, has not been determined, except at the few points where it has 
 been mined. To prove this I have suggested to some parties 
 interested, to bore down to the coal in various places as the only 
 practicable method of determining the facts, and one that will be 
 decisive. 
 
 Experience has shown that the quality of a bed of coal is generally 
 better beneath a high unbroken hill, than where the overlying 
 material is thin and uneven. In view of this, and the fact that the 
 coal-bed seems to thicken to the northward at Buckner's mine, I 
 have suggested that several borings be made on the hill in different 
 directions and at various distances from the mine. 
 
 It is equally desirable also, to prove in the same manner, the 
 region to the westward and southward to the distance of about a 
 mile in each direction, and it is not at all improbable that a bed of 
 coal may be found beneath Eldora, but if so, it will be at a con- 
 siderable depth. If one exists there, nothing can be known of its 
 character without boring. 
 
24 REPORT OF STATE GEOLOGIST. 
 
 Judging from the indications observed, I was led to believe that 
 the best prospect for obtaining coal in this region, is found along the 
 left bank of the river, from a point somewhat west of Backner's 
 mine, to about a quarter of a mile below it; but boring at various 
 points from a mile below Steamboat Rock, to the mouth of Pine 
 Creek, may reveal as gojd or better indications elsewhere. 
 
 Mr. Buckner is now boring for a lower bed of coal at his mines, 
 having reached a depth of nearly a hundred feet below the bed he is 
 now working. The drill has passed most of the way through a blue 
 shale common to the coal-measures. Should the drill reach limestone, 
 the boring ought to be stopped at once, for there is no doubt that it 
 would prove to be sub - carboniferous limestone, below which it is 
 useless to look for coal. 
 
 The quality of the coal at Buckner's mine, the only one now 
 worked, is fair, and if properly separated from the sulphuret of iron, 
 it is as good as Western coal will average. About a foot of the 
 lower portion of the bed is very good, and carefully selected, will be 
 suitable for working iron, and the preparation of illuminating gas. 
 The bed is four feet in thickness and the working is now done along 
 two narrow passages which have not yet penetrated far into the hill. 
 It is the intention of those who are conducting the operations to 
 carry the work in the same direction all along the inner side, thus 
 proceeding beneath the hill, letting most of the roof fall in behind 
 them as they remove the temporary supporting-posts. This plan 
 gives t^em an opportunity to assort the coal in the mine, and throw 
 the refuse behind them. They can also remove the coal more 
 expeditiously and cheaper in this way than in any other. 
 
 Within a few days after the foregoing communication was pub- 
 lished, Mr. Buckner resumed his boring, and his drill soon reached 
 the limestone referred to, when he promptly stopped the work with- 
 out finding any coal beneath the bed he was then working. 
 
 The advantage possessed by the owners of the Eldora coal mines 
 is very great, from the fact that they are situated in a prominent 
 angle of the coal field, which gives them an unusually extensive 
 market. Besides these coal mines, Hardin county has a plentiful 
 supply of wood for fuel also. Upon the sandstone cliffs in the 
 vicinity of the coal mines, the white pine and white birch are both 
 
REPORT OP STATE GEOLOGIST. 25 
 
 observed, whicli are very unusual in this part of the State, and is 
 believed to be the southern limit, at least of the birch. Hon. C. F. 
 Clarkson has successfully transplanted quite a number of both of 
 these trees to the grounds around his residence, a few miles away, 
 where they are growing thriftily upon prairie soil, and where he has 
 already proven, if proof be needed, that all kinds of our indigenous 
 trees will thrive upon our prairies, if they are protected from the 
 annual fires. 
 
 HAMILTON COUNTY. 
 
 Proceeding westward, the next examinations were made along 
 Boone River, in Hamilton county. It was desirable that the expo- 
 sures of coal along the northern border of the coal-field should be 
 examined, for the purpose of comparison with those of the southern, 
 central and western parts, the better to understand the character of 
 the different beds, and their mode of occurrence. Our coal-field is a 
 very large one, and it is intended to devote the greater part of the 
 field-labor of the next two years to its examination. The results 
 of that trip were quite satisfactory, because a better development 
 of the coal-moasure strata was found along the northern border of 
 the coal-field, and the coal found to be more abundant and of better 
 quality than might reasonably have been inferred before examina- 
 tion. While at Webster City I was informed that a thin bed of coal 
 had been found a few miles north of town, but no examinations were 
 made in that direction. It is not impossible that coal should be 
 found there, but since the sub-carboniferous rocks, below which no 
 coal can be expected, are seen in the river banks half a mile below 
 town, and the general dip of the strata being to the southward, 
 Webster City is evidently very near the northern boundary of the 
 coal-field, and consequently a large expenditure of money in the 
 search for coal in that direction could not be recommended. 
 
 To the southward, however, along Boone River and some of its 
 tributary creeks, the case is quite different, for here large quantities 
 of coal exist, as may be seen by any one who will take the trouble 
 to go to the localities, where it is to be seen in natural exposures in 
 the hill sides. 
 4 
 
26 REPORT OF STATE GEOLOGIST. 
 
 Going down Boone River, the first exposure seen was on the right 
 bank, in the hill side, about four miles from town. The coal is of 
 good quality, has been worked to a considerable extent, and the bed 
 is said to be four feet thick, which no reason was seen to doubt. 
 Between this point and Sternberg's mill, which is six miles from 
 town, the same bed of bituminous coal again appears, as docs a bed 
 of cannel coal, two feet in thickness and of fair quality. The latter 
 bed lies seveial feet beneath the former, and is, of course, no way 
 connected with it. Near Sternberg's mill and also at various points 
 for a number of miles below the mill, the coal makes its appearance 
 in the banks where they are rendered stet='p by the washing of the 
 river. These beds are doubtless continuous in broad continuous 
 layers beneath the surface, over a large area, and have become ex- 
 posed to view in places by the deepening of the river valley by its 
 own stream. They may doubtless be reached with comparatively 
 little labor from the gentler slopes of the river valley, and when the 
 demand will warrant it, as it probably will in the future, they may 
 be mined by sinking shafts to them from the higher lands away from 
 the river. As much attention as possible was given to the quality of 
 the coal, and the conclusion arrived at is, that the coal along Boone 
 river is fully equal to the average of AVestern coal. None was seen 
 in this region which contains so much sulphur and other impurities, 
 as many beds do which are profitably worked in other places. It 
 was noticed that ver;)^few of the inhabitants were using coal for fuel, 
 but this was fully explained by the fact that no regular system of 
 mining is adopted, and the supply is consequently too uncertain to 
 be depended on. 
 
 This supply is also at present rendered somewhat unnecessary by 
 the abundant growth of excellent timber which the region aifords, 
 but with its present rapid settlement, and the prospect of the early 
 extension of the Dubuque and Sioux City Railroad, the case will soon 
 be different, and large quantities of coal will then be demanded for 
 the regions eastward and northward of Webster City. This want 
 must be supplied in great measure by the Boone river coal-mines. 
 
 WEBSTER COUNTY. 
 
 After going down Boone river about twelve miles from Webster 
 
REPORT OF STATE GEOLOGIST. 27 
 
 City, we crossed over to the Des Moines, examining a number of coal 
 exposures along that river and its tributaries on our. way up to Fort 
 Dodge. Near this place the coal and gypsum were briefly examined, 
 but since the region was subsequently examined with more care, a 
 fuller account of its resources will be found on another page. 
 
 One can not visit the valleys of the rivers referred to in the pre- 
 ceding pages without being impressed with the fact that they are 
 destined to be soon filled with a wealthy and prosperous population, 
 and to be the seat of thousands of happy homes ; and there seems no 
 reason to believe that future bards may not arise to sing the beauties 
 of the Cedar, the Iowa, the Boone and Des Moines, since many a 
 stream has become famous in song which does not possess half their 
 native beauties. 
 
 Returning to prepare the outfit for the work in the western part of 
 the State, a short time was spent in 
 
 JONES COUNTY. 
 
 Time would not permit the full examination of Jones county at the 
 time it was visited, but the long and favorably known quarries near 
 Anamosa received an examination, and the following account of them 
 was sent to the Anamosa Eureka in May, 1866 : 
 
 Although Jones county is entirely beyond the limits of the great 
 Iowa coal - field, yet the large bodies of timber along the Wapsipincon 
 and Maquoketa rivers will yield a plentiful supply of fuel for all time 
 to come. The supply is now more than sufficient, and the tendency 
 of the forests to encroach upon the prairies where the fires are kept 
 out, is apparent to every one, so that the increase in this respect will 
 supply the demands of an increasing population. 
 
 An examination of the brick of several houses in your place shows 
 that you have a supply which is good, and no doubt abundant, of this 
 indispensable building material. 
 
 The soil, as far as seen, is a rich dark loam, containing just enough 
 sand to make it warm and mellow, without approaching barrenness ; 
 and that much of the material having a sandy appearance, is really 
 not silicious in its composition but results from the disintegration of 
 the magnesian limestones which underlie the county. 
 
 Thos3 who have visited the lead mines of Dubuque, have seen 
 
28 REPORT OF STATE GEOLOGIST. 
 
 large quantities of material thrown out of the diggings near the 
 surface, which has the appearance of sand, but in reality contains 
 none at all ; for it is composed of the disintegrated rock from which 
 the lead ore is obtained, which is also a magnesian limestone, although 
 it belongs to a different geological period from that which underlies 
 Jones county. Some of your readers, who learned their mineralogy 
 from Comstock's manual, will remember that under the head of 
 Magnesian Limestone he has the following paragraph : " Where 
 magnesia exists in considerable quantity in the soil, it wholly destroys 
 vegetation." This statement is now known to be entirely without 
 foundation in fact, of which the people of the northwestern part of 
 our State have the fullest evidence from the fact that, although their 
 soil is almost entirely underlaid by, and largely derived from 
 magnesian limestone, it is nevertheless, as a whole, as productive as 
 any with which a beneficent Creator has spread the earth. However, 
 since the world owes so much to the labors of scientific men, we 
 ought in justice to forgive their occasional errors and strive to 
 correct them. 
 
 Nearly all the rocks of Jones county, belong to the Upper Silurian 
 age, and those in the vicinity of Anamosa are believed to be geo- 
 logically the highest of that age occurring in the State, but I had 
 not time to satisfy myself fully upon these geological questions, and 
 consequently felt constrained to devote all the time at my disposal 
 to matters of immediate practical importance to the people. The 
 beds of rock exposed along the river in your city, are thought to be 
 continuous with those at the quarries three miles distant, although 
 the stratification is quite different. Notwithstanding this difference, 
 the chemical composition and contained fossils are nearly or quite 
 the same, and the peculiar stratification which is so valuable a 
 character at the quarries, seems to be confined, so far as could be 
 ascertained, to an area not much, if any, more than three miles in 
 extent. 
 
 Although this area is thus limited, the supply of excellent Stone 
 is practically unlimited. It would surprise one who knows the 
 reputation that this stone has already obtained abroad, to visit the 
 quarry and learn the fact that all the stone which has yet been taken 
 
REPORT OF STATE GEOLOGIST. 29 
 
 out for the home and distant markets, has only just opened one 
 quarry to a degree that lays bare the best and most profitable layers, 
 and two or three others which can hardly be said to be yet opened. 
 
 This principal quarry is now owned and worked by Messrs. Haines 
 & Co., and is generally known as the " Anamosa Quarry." Two 
 and a half miles northeast of this point, Mr. John Burham has long 
 had a quarry in operation, but I did not get time to visit it. 
 
 Messrs. Parsons & Webb have just commenced opening a quarry 
 one and a half miles west of the "Anamosa Quarry," adjoining the 
 railroad, with good indications of procuring a large supply of excel- 
 lent stone. These gentlemen have also commenced the erection of a 
 large kiln for the manufacture of lime from their broken stone. 
 Samples of mortar prepared from lime made from this stone were 
 seen which were equal in quality to any. It is intended to have 
 some of the layers tested for the purpose of learning whether it may 
 be used for the preparation of hydraulic cement. It will be 
 remembered that some of the best of these cements are prepared 
 from magnesian limestone. 
 
 For a description of the character of the Anamosa stone, I shall 
 be obliged to confine myself to that of the quarry of Messrs- Haines 
 & Co., because it is the only one which has been worked to a sufficient 
 extent to disclose the full value of the material ; yet there is every 
 reason to believe that at almost any point m the hills in the imme- 
 mediate vicinity the same quality of stone will be obtained, for the 
 layers extend horizontally irrespective of the unevenness of the sur- 
 face, the only questions to be decided are as to the amount of labor 
 required to remove the superficial material, and the convenience of 
 shipping the stone when quarried. 
 
 The common character and appearance of magnesian limestone in 
 a natural exposure, of whatever geological age, is rough and pic- 
 turesque, like the exposure seen on each side of the Wapsipinicon 
 just below your mills ; but the stone of the quarries, although mag- 
 nesian, is a remarkable exception in its stratification. It is fine 
 grained, evenly and horizontally bedded, some of the layers splitting 
 readily into slabs from half an inch to one, two, three or four inches 
 in thickness, and of almost any desired size ; many of winch are as 
 even in thickness and surface as a board from a planing; machine 
 
gQ REPORT OF STATE GEOLOGIST. 
 
 The surface of a few of the layers is slightly rough, but they are 
 very uniform in thickness. Some of the layers will furnish blocks 
 four feet in thickness if desired ; and from very many of them are 
 obtained almost perfect ashlars for caps and sills, water- table, store- 
 front columns, &c. The bedding surfaces are so smooth and true in 
 many instances as not to require to be touched with a chisel. 
 
 The whole front exposed at this quarry is about ninety feet above 
 the river, giving just room enough for the railroad between it and 
 the quarry. From fifteen to twenty feet of the lower beds are more 
 porous in texture than those above, but they are harder, heavier, and 
 doubtless fully as durable. The stone of the upper layers is rather 
 soft when first taken out, but in a couple of days it becomes quite 
 hard and firm. 
 
 The weight of a cubic foot, as given me by Mr. Philip Haines, is, 
 when quite dry, 140 lbs. for the upper layers, and 160 lbs. for the 
 lower. 
 
 Of the present and prospective value of these quarries, it is not 
 easy to form a correct estimate, but there is little danger of placing 
 it too high. The present market for dressed stone and slabs extends 
 from Cedar Rapids to Dubuque, and also so far as Independence in 
 Buchanan county ; and as the population increases the demand will 
 be more extended and much greater than now, for there are no simi- 
 lar quarries within a long distance from this, if any others exist in 
 the State. 
 
 The broken stone for common walls finds a ready market at the 
 various stations along the whole length of the Dubuque Southwestern 
 Railroad, although the ordinary rough stone can be obtained at those 
 points. 
 
 The great advantage of these stones for cellar walls is that they 
 can be readily joined so closely that rats can not burrow through 
 them; they require less mortar to bed them, less labor to lay them, 
 and make a firm and stronger wall. The broad slabs make the best 
 walks that can be desired, and will outlast brick for that purpose. 
 
 BURLINGTON AND ITS VICINITY. 
 
 The name of Burlington will be known wherever American geology 
 is studied, because the " Burlington limestone " has produced a greater 
 
REPORT OF STATE GEOLOGIST. 31 
 
 variety of interesting fossils than any other known locality in the 
 world. Of crinoids alone, more than three hundred species as at 
 present classified have been found in the limestones of that vicin- 
 ity. Beside this, more than one hundred species of other fossils 
 have been obtained from the stnta which underlie the Burlington 
 limestone at the same locality. The rocks which constitute the 
 framework of the high bold hills around Burlington belong to the two 
 lower members of the sub - carboniferous group, namely, the Kinder- 
 hook series, and the upper and lower Burlington limestone. The^ 
 former consists of five or six distinct beds of limestones and fine- 
 grained sandstones, none of which are of much economic value. 
 The two groups of strata composing the Burlington limestone contain 
 material of the greatest value in building the city. The Kinderhook 
 series here reaches a thickness of about one hundred and forty feet, 
 sixty feet of which was ascertained by boring, while the limestones 
 rest upon it and form the bold exposures which constitute so promi- 
 nent a feature of the scenery around the city. The Burlington 
 limestone, as well as a part of the series beneath it, are to be seen 
 in the bluff's across the river in Illinois, and with which those of the 
 Iowa side were no doubt continuous before the river had cut its 
 valley down to its present depth, and to a width of six miles at this 
 point. At the base of the lower Burlington limestone is a bed of 
 light gray limestone, about four feet in thickness, which upon close 
 inspection will be found to be composed of minute rounded grains, 
 and is called in geological language oolitic limestone. It is quarried 
 and wrought with facility, and has a good appearance when cut, but 
 it is as worthless for any purpose, except the preparation of lime, as 
 the friable sandstone beneath it; for it is sure to disintegrate rapidly 
 and completely upon exposure to the frost. It has so good an 
 appearance when taken from the quarry, and can be obtained in such 
 desirable shapes, that it has been used for paving and curbstones in 
 various parts of the city, as well as for capping embankment walls, 
 &c., and in every instance it has been broken up and destroyed by 
 the action of the frost alone within a year or two. 
 
 The heavy beds of limestone at the brow of the bluffs furnish a 
 great part of the paving and building stone used in the city. It is 
 unlimited in quantity, is not affected by the action of the fr^^st, and 
 
32 REPORT OF STATE GEOLOGIST. 
 
 is a good stone for ordinary purposes, but the upper beds of lime- 
 stone which overlie this, although they do not appear at the brow of 
 the hills within the city limits, furnish so much fine material for 
 hewn stone that the former is not so often used for that purpose as 
 it otherwise would be. These upper beds are seen to cap the bluffs 
 below the city a few miles, but many of the quarries opened in them 
 are in the southern and western part of the city, and also beyond 
 its limits in those directions. This stone, when hewn, closely resem- 
 bles in color the worthless limestone before referred to, but close 
 examination will show that it has none of that peculiar structure 
 resembling the roe of a fish, which the worthless stone has. The 
 stone of these upper beds is of a pleasing appearance, as durable 
 as the everlasting hills, and unlimited in quantity. 
 
 The quarry of Mr, Nat. Irvin, in these beds, h?s furnished a large 
 quantity of excellent hewn stone, and those of Mr. Peter Smith, 
 farther to the southwest in the same beds, are noted for the excel- 
 lent quality of lime obtained from them. The quarries of Mr. Parr, 
 a few miles below the city, are in the lower beds of limestone, con- 
 tinuous with those at the brow of the bluffs, within the city limits, 
 the lime from which has had a first-class reputation. But good 
 stone is so abundant here, and quarries so numerous, that it is un- 
 necessary to make more definite reference to them. The brick - clays 
 upon the hills are abundant, and of as good quality as any to be 
 found in the State. Aside from the materials mentioned, there is 
 little probability that mineral substances of economic value will ever 
 be found here. 
 
 Since the rocks of this vicinity are older than the coal - measures, 
 and consequently geologically below them, there is no hope of finding 
 coal here, but in both an easterly and westerly direction they pass 
 beneath the surface, and have received the coal -measure deposits 
 upon them, and it is in these directions that one must go to procure 
 a supply of coal. 
 
 The coal - measure rocks do not appear until Skunk river is passed, 
 going in a westerly direction, but other higher members of the sub- 
 carboniferous group are found to lap on to the Burlington limestone 
 as one goes in that direction. The Keokuk limestone is next in the 
 series above the Burlington limestone, and on Long Creek, seven 
 
REPORT OF BTA.TB GEOLOGIST. 33 
 
 miles west of the city, some important quarries in that limstone are 
 worked. The principal quarry is located near the mouth of a small 
 branch -which empties into Long Creek, a few hundred yards north 
 of the ford, and consists of three or four massive layers from six or 
 eight inches to two or three feet in thickness. Both above and below 
 those layers other stone is seen, but it is of little or no economic 
 value. Although the stone of these quarries is so different in litho- 
 logical character and appearance from the Keokuk limestone, as seen 
 at Keokuk and Nauvoo, they are nevertheless a part of that forma- 
 tion which, extending northward from the places named, laps upon 
 the Burlington limestone, as the latter formation dips beneath it to 
 the southward and westward, its nearest approach to Burlington 
 being on the Poor - House Farm, four miles from the city. It is 
 quite different, also, from that of the same beds in the immediate 
 vicinity, which, although 'continuous, present a marked change within 
 a few rods. While in the city, a few weeks ago, I procured a speci- 
 men of the rock and had it analyzed. Prof. Hinrichs reports it to 
 be highly magnesian. It is much more so than any rock of the same 
 formation in this vicinity or elsewhere, but less so, however, than the 
 dolomites of northeastern Iowa ; while at the typical localities of the 
 same formation, Keokuk and Nauvoo, it contains little, if any, mag- 
 nesia. 
 
 This stone has been introduced within the last few years, and has 
 been found to withstand the action of frost better than any other 
 stone obtained in this vicinity. It presents a pleasant appearance in 
 a building, and is much used for caps, sills, water-tables, store - fronts, 
 &c. It is hewn rather more easily than the light grey stone of the 
 quarries in the upper portion of the Burlington limestone, before 
 mentioned, and which has heretofore furnished the best accessible 
 material for such purposes. It is generally of a uniform texture, and 
 without doubt a durable and valuable stone, perhaps the best yet 
 found near the city. Yet it has occasionally, but not frequently, soft 
 places in it, which should be avoided in hewing, as it will ultimately 
 crumble in these places and thus deface and injure the structure. 
 Although the exposures of stone of this peculiar character are limited 
 in extent, yet they will furnish large quantities of excellent material 
 for many years to come. 
 
34 BEPORT OF STATE GEOLOGIST. 
 
 We are accustomed to regard limestone as one of the most inde- 
 structible of all our building materials, which it dojbtless is, yet the 
 best limestone is subject to more or less erosion by " the tooth of 
 time," which popular expression the chemist takes the poetry out of, 
 by telling us that it is caused by carbonic acid taken out of the 
 atmosphere by the falling rains, coming in contact with the limestone, 
 which is a proto-carbonate, constantly changing minute quantities of 
 it to a bi-earbonate, which is soluble in cold water, but the lime 
 becomes precipitated again as a proto-carbonate, or common limestone, 
 when exposed to the atmosphere, or to an elevated temperature. We 
 find it thus deposited as stalactites, and stalagmites in caves ; as a 
 rough porous limestone where some springs issue from the earth 
 and also often forming a heavy white lining to our tea - kettles. Thus 
 it will be seen that when even the rocks are disintegrated they are 
 not destroyed, but new combinations are formed from the same 
 materials. It is not in the laboratory alone that chemical changes 
 are produced, but they are constantly going on around us, and it is 
 always interesting, and sometimes profitable to trace them. 
 
 Those who are scientifically or curiously inclined may observe 
 some interesting results of such chemical changes in nature, beneath 
 the overhanging bluffs at Starr's mill, three miles northwestward 
 from Burlington. That portion of the strata which is seen to be 
 more rapidly disintegrating than the other, and leaving the solid 
 limestone projecting above contains considerable quantities, both of 
 carbonate of magnesia and sulphuret of iron. The oxidation of the 
 sulphur produces sulphuric acid, which uniting with the magnesia by 
 displacing the carbonic acid, forms native sulphate of magnesia. 
 This substance is, no doubt, formed in other places, but being very 
 soluble it is usually carried off by the rains, and thence by the 
 streams to the sea, the waters of which are known to contain large 
 quantities. But here the overhanging cliff prevents the rain from 
 reaching it, beneath which it is found as a white encrustation upon 
 the stones among the fine substance resulting from the decomposition 
 of rock. By re - dissolving some of this native sulphate of magnesia, 
 and allowing it to crystalize, as fine a sample of epsom salts was 
 produced as can be purchased at any of our druc stores. "It is 
 
REPORT OF STATE GEOLOGIST. 35 
 
 proper to say, however, that this substance is obtained so cheaply 
 by artificial means, that small quantities of it may be regarded only 
 as interesting specimens in mineralogy. 
 
 Dcs Moines county is abundantly supplied with building - stone 
 which crap out in almost one continuous exposure along the Missis- 
 sippi river bluiFs, from the northern to the southern line. Also 
 scarcely less abundantly, along Skunk and Flint rivers. Brush, 
 Spring and Long creeks. 
 
 Its other advantages are too well known to need mention here. 
 
 DAVIS COUNTY. 
 
 Davis and Appanoose counties received only partial examinations 
 at the time they were visited, because the plans adopted for the season 
 contemplated the special examination of the southwestern portion of 
 the State first. 
 
 Upon Salt creek, near its junction with Soap creek, where the 
 Bloomfield road crosses the former, there are several " salt-licks " or 
 springs, from which samples of the water were obtained for analysis. 
 In consequence of previous continued rains they were flowing freely. 
 Therefore the water was proportionally less saline than usual. Mr. 
 S. D. Wells afterward sent samples from another spring on his land 
 in the same neighborhood, (Section 15, 70, 13,) and the following is 
 the result of a preliminary examination by Prof. Hinricbs, a fuller 
 account of which will be found in the Professor's report on another 
 page: 
 
 The water of the first named spring was found to contain soda, 
 potassa, lime, iron, alumina, and a little magnesia; also, chlorine and 
 sulphuric acid. These substances of course exist in combination 
 with each other, and the water may, from present indications, be 
 regarded as common spring water, containing common salt, alum, a 
 little copperas, and, as is usual with nearly or quite all the spring 
 waters of the State, a considerable proportion of lime. 
 
 The spring on Mr. Wells' farm was similar to the other, in the 
 character of its water, except that it did not contain so great a pro- 
 portion of the substances named, particularly of potassa, while the 
 presence of iron and magnesia were not detected in it. 
 
 These waters have some characters in common with those of some 
 
36 REPORT OF STATE GEOLOGIST. 
 
 of the mineral springs resorted to for medicinal purposes, but in 
 detail they vary considerably from those commonly used. The spring 
 on Salt creek contains a considerable proportion of salt, but probably 
 not enough to make it valuable for that purpose. 
 
 The springs, like many similar ones in other parts of the coal-field 
 of the State, issue from the shales, limestones and clays associated 
 with the coal. 
 
 These springs are a favorite resort for cattle and horses, which 
 drink the water with a great relish. The early settlers of Davis 
 county used to shoot many deer here, where they came in great 
 numbers to drink, and doubtless long departed generations of Indians 
 did the same. 
 
 It is commonly believed that springs which animals resort to with 
 unusual avidity always contain a considerable proportion of salt. 
 But this is not the case, for many springs are known which contain 
 an amount of sulphuretted hydrogen that renders the water quite 
 disagreeable to most persons, but no salt ; yet animals become very 
 fond of such water, and drink with as much eagerness and evident 
 relish as they do saline water. 
 
 Davis county is known to contain large quantities of excellent 
 coal, but the only exposures seen were one nearly four feet thick a 
 few rods below the spring before mentioned on Salt Creek, and 
 another half a mile above the mill of Mr. Peter Hendricks, on Soap 
 creek. 
 
 A foot or two above the bed of coal at this locality, a four foot bed 
 of compact, bluish limestone is found, from which Mr. Hendricks, 
 some years ago, manufactured considerable quantities of hydraulic 
 cement. Some of this cement was used in the construction of the 
 locks on the Des Moines River, and is said to be satisfactorily tested. 
 No definite analysis of this rock has yet been made, but it is sup- 
 posed that its hydraulic property is due to alumnia and not to mag- 
 nesia, like that of the northern part of the State. 
 
 Beside an abundance of coal, Davis county is bountifully supplied 
 with fuel in the form of forest trees. 
 
 PETROLEUM. 
 
 During the year 1865, and also a few previous years, there was 
 
REPORT OF STATE GEOLOGIST. 37 
 
 much excitement and speculation throughout the country in relation 
 to petroleum. This excitement extended even to our own State, and 
 resulted in much useless expenditure of money in the search for oil. 
 In reply to numerous inquiries concerning the probabilities of finding 
 petroleum in Iowa, the following article, slightly modified in the 
 wording, but not in character, was sent to three or four of the news- 
 papers of the State on June 15, 1866 : 
 
 " With the successful boring of the first well for petroleum in 
 Titusville, Pa., a spirit of speculation was aroused, or rather was 
 given a new direction, which went on increasing as one success fol- 
 lowed another, in that and adjoining States, until it has extended not 
 only over those portions of our country where the search for petro- 
 leum was likely to be attended with success, but also to regions 
 where success could not possibly reward those who expended their 
 money and and labor in such enterprises. Some of our own citizens 
 caught the same spirit, and commenced the search for this valuable 
 product, but thus far with invariable failure, so far as the ultimate 
 result has been learned. In view of these facts my opinion has been 
 often solicited as to the probability of finding petroleum in paying 
 quantities in our own State, which I now take this public method of 
 stating, together with the reasons for entertaining it. The impor- 
 tance of this question, as well as of the responsibility which my 
 ofiicial position imposes upon me, are well considered; but it is be- 
 lieved that the true interests of the people of Iowa are as well 
 served by informing them where it is useless to expend their money 
 as they would be by directing them to opportunities of making profi- 
 table investments. 
 
 " The great majority of the men engaged in the search for petro- 
 leum, have commenced the enterprise in good faith, but in too many 
 instances with their visions blinded by bright hopes of sudden wealth ; 
 honestly inducing others to join in the expense and share with them 
 the great profits which they believed themselves sure to obtain. But 
 this is not the worst feature of these profitless enterprises. Design- 
 ing men have induced others to furnish capital for prosecuting the 
 development, or purchase of reputed oil lands which perhaps they 
 themselves had "salted," or rather oiled; or concerning the great 
 value of which they had obtained a report from some geologist of 
 
38 REPORT OF STATE GEOLOGIST. 
 
 easy virtue, or one who was better known for his connection with 
 such schemes than for his scientific attainments." 
 
 These remarks are not to be understood as in unj respect of a per- 
 sonal character, but that such practices have been committed, is too 
 true to be doubted. Neither have I any words of disrespect to offer 
 concerning those geologists who are in the habit of examining such 
 lands for the purpose of giving an honest scientific opinion of them. 
 The world owes much to such men, and their labors are often under- 
 estimated. 
 
 First then, expenditures of money and labor, should be made with 
 great caution in our State, because it has been estimated, and I 
 think with some reason, that every dollar's worth of petroleum 
 obtained in the United States has cost a dollar in its production. If 
 this is true the State at large will be the loser, even if some 
 individuals are successful, because there is no reason to believe that 
 our State will produce at best even an average amount of petroleum. 
 The primary origin of petroleum, is believed to be without doubt in 
 fossilized vegetable substances, — probably marine — which existed 
 and accumulated in the sediment which now forms the rock from 
 which it is derived. All rocks in which it has its origin as such, are 
 highly bituminious, or at least carbonaceous, yet it is often obtained 
 in the more porous rock above that in which it actually originated. 
 
 In all known instances where petroleum has been obtained in pay- 
 ing quantity in the United States, it has had its origin in heavy 
 deposits of these carbonaceous strata; no slight deposits having been 
 known to produce any considerable quantity, even when very rich in 
 the carbonaceous ingredient. Sometimes the material of these slight 
 deposits will yield petroleum by distillation, but as a natural product, 
 the conditions required seem in all cases to be in connection with 
 heavy deposits of carbonaceous strata, and at considerable depth 
 beneath the surface. 
 
 Although the illuminating oil formerly obtained by the distillation 
 of coal is the same in its chemical composition as that obtained from 
 petroleum ; and sometimes petroleum is found in a natural state 
 associated with coal -bearing strata, yet in the great majority of 
 instances it has in its origin no connection whatever with coal. In 
 
REPORT OF STATE GEOLOGIST. 39 
 
 the United States far the greatest amount of petroleum has its origin 
 in strata of Devonian age, — the age preceding that in -which the 
 coal was formed. It has in several instances been found in rocks of 
 more ancient date than the Devonian, but in those early ages it is 
 not probable that vegetation existed in sufEcient amount to produce 
 the carbon which is believed to have been necessary to give origin to 
 large quantities of petroleum. 
 
 Now, in applying these general remarks upon the origin of petro- 
 leum to our State, it is not forgotten that it has not yet been care- 
 fully examined in all its parts, but enough of its general geology is 
 known to decide the fact, with scarcely a doubt that we have no heavy 
 deposits of carbonaceous strata, except the coal, underlying its sur- 
 face which precludes the probability of obtaining petroleum beneath 
 our surface. 
 
 Again, when it has been found in connection with coal, it has been 
 with cannel, and not bituminous coal. We have a few beds of cannel 
 coal in Iowa, but the greater part is bituminous. Although we have 
 coal enough in Iowa to serve a crowded population for many genera- 
 tions, yet the development of our coal strata is not thick enough nor 
 rich enough in carbonaceous matters, I think, to produce petroleum 
 in paying quantities. That what are usually regarded as favorable 
 indications, and that small quantities of it have and may yet be 
 found, there seems no reason to doubt. Mr. H. T. Woodman, of 
 Dubuque, has shown me some light- brown carbonaceous shale from 
 the Lower Silurian rocks (Trenton limestone) near Dubuque, and 
 also some similar shale from the same beds at Shullsburg, Wisconsin, 
 which M'ill burn with a flame equal to the best cannel coal. Similar 
 shale is also found in the northeast portion of the State in the so- 
 called Hudson Kiver strata, but these are of too slight development 
 to yield any considerable amount of petroleum. Both of these de- 
 posits doubtless extend beneath the surface of the State to the south- 
 ward and westward, where they may probably be reached by boring, 
 but it is not believed that any petroleum would be obtained from them 
 if they were reached, because the carbonaceous deposit, if it exists 
 there, is doubtless too light to have developed it. Time, and a 
 further collection of facts, may cause a change in the opinion here 
 
40 REPORT OF STATE GEOLOGIST. 
 
 expressed ; but with the possession of present information, I am not 
 disposed to encourage the search for petroleum, in Iowa. 
 
 The excitement in regard to petroleum was decreasing when the 
 foregoing article was written, and now nothing is known of its exist- 
 ence anywhere in the West. 
 
 APPANOOSE COUNTY. 
 
 The geology of Appanoose county may, for my present purposes; 
 be summed up in these few words. It lies wholly within the great 
 Iowa and Missouri ^coal - field; the coal, limestones, sandstones, and 
 clays of which, underlie a drift deposit of varying depth, from 
 twenty to perhaps fifty or sixty feet upon the higher lands ; upon 
 which the beautiful and fertile soil is spread, and through which the 
 streams have eroded their way down to the series of coal - measure 
 rocks just mentioned. 
 
 The rocks exposed near Centreville are believed to belong to both 
 the upper and middle series of coal-measure strata as sub-divided by 
 some geologists, the limestones belonging to the former, and the 
 coal and its associated shales, to the latter. If this is the case, more 
 coal may be expected to exist beneath the bed now worked by Mr, 
 Talbot at his mill a mile from town. It may also be reasonably 
 sought for on the lower slopes of the Chariton valley, particularly in 
 the northern and northwestern parts of the county. 
 
 Coal has been mined from a three-foot bed at several points in the 
 vicinity of Centreville. The only mine visited was that at Talbot's 
 mill, the coal of which was found to be of superior quality. 
 
 Appanoose county is well supplied with everything necessary to 
 make a community prosperous and wealthy, such as wood, coal, 
 building- stone, brick -clays, and fertile soil. The latter seems to 
 have been largely free from the blighting curse of non-resident 
 land owners. 
 
 WAYNE COUNTY. 
 
 Those whose homes are in less beautiful lands than Iowa, and who 
 desire to understand in all its broad expansiveness, the meanin<^ of 
 the word "Prairie," should visit Wayne county, for here these beautiful 
 lineaments in the features of our mother earth are to be seen in all 
 
KEPORT OF STATE GEOLOGIST. ^1 
 
 their loveliness. It is difficult for one who has never seen them to 
 form a correct idea of their character, and indeed to do this, one must 
 see them in many different regions, for they vary much in this 
 respect, although in general appearance they are so much alike. 
 Scientific men have entertained various opinions concerning their 
 origin, many of which were circumscribed by their want of opportu- 
 nity to observe all their varieties. Those of Iowa are nearly all such 
 as are known as " rolling prairies," and yet those of the northern 
 and western parts of the State differ from each other in character. 
 This difference is due, in part at least, to the more complete drainage 
 of the southern portion, and this drainage is due to the deeper erosion 
 of the river valleys than those of their tributaries farther to the 
 northward. When the continent was finally raised from the diluvial 
 sea, that portion of it which is now our state doubtless presented a 
 surface which was only slightly undulating, the longitudinal depres- 
 sions of which were in the same direction of, and gave origin to the 
 course of the rivers and streams. 
 
 Wayne county presents an excellent example of a well - drained 
 prairie region, lying as it Joes where the Medicine, and the South 
 Fork of Chariton rivers take their rise. As one stands upon the 
 prairie in the central part of the county, its rolling character is 
 somewhat obscured by the distant view which is only broken by lines 
 and groves of forest trees that reveal the presence of the streams 
 into which the surface waters are gathered by the multitude of gently 
 sloping and gradually deepening ravines which give the prairies of 
 the region their characteristic rolling appearance. 
 
 The fact that this county lies about the head waters of the streams 
 indicates a considerable elevation, but this is not definitely known. 
 That of Corydon, however, is probably not far from the same as 
 Chariton, the county seat of Lucas county, which is, according to 
 Mr. Thielson, five hundred and twenty - four feet above the level of 
 the Mississippi at low water at Burlington. This, added to four hun- 
 dred and eighty - six feet, the elevation of that point above the Gulf 
 of Mexico, would give to Corydon, in round numbers, an elevation of 
 about one thousand feet above the level of the sea. The soil of 
 Wayne county is of excellent quality, and it is doubtful if an equal 
 area can be found any where having so little waste and untillable 
 
42 REPORT OF STATE GEOLOGIST. 
 
 land. The only elements of prosperity wanting here are a sufficient 
 supply of stone and timber. The heavy deposit of drift, which 
 underlies the deep soil, renders the beds of stone inaccessible, which 
 no doubt exist at too great a depth to be profitably quarried. This 
 want must be supplied from other places, and by the manufacture of 
 brick. 
 
 Timber can be profitably cultivated, as is being demonstrated very 
 extensively, in diiferent parts of the State ; besides which the natural 
 growth of forest trees will rapidly encroach upon the prairies as soon 
 as the fires are kept out. Coal of good quality has been found in 
 the northeastern part of this county, and a few exposures of stone 
 are also seen in Wright, and South Fork townships, but depending 
 on these alone, little could be said of its geology, except that it is 
 known to lie within the great Iowa and Missouri coal-field, as do also 
 all of those which surround it. This renders it entirely reasonable 
 to prospect for coal by boring at almost any point within it. Owing 
 to the small nnmber of exposures of the series of strata which are 
 generally found associated with the beds of coal, little more can be 
 suggested, than that borings might be made in almost any part ot the 
 county with the reasonable hope of finding coal within two or three 
 hundred feet if they are commenced in the deeper valleys. It is 
 probable also that the upper beds of coal may be reached within one 
 hundred and fifty feet. In case such borings are undertaken, it is 
 probable that a considerable thickness of limestone would be passed 
 th'-ough. 
 
 DECATUR COUNTY. 
 
 Passing westward from Wayne to Decatur county, one observes 
 a marked change in the general aspect of the country, which is 
 due to a greater proportion of timber in the latter, together with 
 the existence of more numerous and larger streams. Some portions 
 also of Decatur county are more uneven, but this unevenness is 
 principally confined to the wooded lands in the vicinitv of the rivers, 
 while much of it is covered with prairies of that peculiar beauty 
 which characterizes Wayne. 
 
 The same geological formations also underlie both counties, but 
 in Decatur the rivers have eroded their channels deeper into them 
 
REPORT OF STATE GEOLOGIST. 43 
 
 than they have in Wayne, Avhere the streams are comparatively small. 
 It is this alone that has produced the difference in the character of 
 their surfaces. 
 
 All the rocks of Decatur county, at least those above the level of 
 Grand River Bottom, are understood to belong to the upper or unpro- 
 ductive coal-measures. Thus far no coal has been found in this county, 
 but there are good geological reasons for believing that it does exist 
 there at considerable depth beneath the surface. Should explorations 
 be made, it should be done by sinking shafts. These ought to be com- 
 menced in the deeper valleys, for it is believed that the higher strata 
 do not contain any coal ; and since the strata of the county are prac- 
 tically level, by commencing in the valleys the labor and expense of 
 digging through the upper strata, which are largely composed of 
 limestone, v^ould be avoided. The upper coal -measure limestone just 
 referred to affords a great abundance of excellent building - stone, 
 more particularly along Grand River and its tributaries. Should 
 coal never be found in Decatur county, its inhabitants will never 
 want for fuel, because it is well supplied with a thrifty growth of 
 forest trees. The county is well watered by its springs and nume- 
 rous streams, and its soil has no superior for fertility. 
 
 Little has heretofore been said of the natural beauties of the regions 
 thus far passed through. It is not because they were found below the 
 average in this respect ; but upon this bright June morning, in our 
 journey down the west side of the valley of Grand River, our eyes 
 have been resting upon views of impressive loveliness. The wooded 
 hillsides, sloping down to the river from the prairied highlands ; the 
 bottom prairie, level as a floor ; the belts of heavy timber skirting 
 the stream, are characters in the landscape peculiar to the West, and 
 around which the affections of the children reared amid these scenes 
 will cling as long as memory lasts. 
 
 RINGGOLD COUNTY. 
 
 Wayne has been described as a prairie county, while Decatur, 
 adjoining it on the west, is found to possess a well - proportioned 
 diversity of prairie and timber land. Proceeding still further west- 
 ward, Ringgold county again presents us with extensive and almost 
 continuous prairies which, however differ somewhat in character from 
 
44 REPORT OF STATE GEOLOGIST. 
 
 those of Wayne ; in consequence of the difference in the drainage 
 systems of each, and not to any material difference in the character 
 of their formations. 
 
 The drift - deposit in Einggold county is very thick, and its distinc- 
 tive topographical features are produced by the great depth to which 
 its streams cut their valleys into that formation. 
 
 Wayne county is drained in almost all directions from its central 
 portions, by the upper branches of Chariton and Medicine rivers, 
 most of which pass out of the county before they have increased to 
 any considerable volume, and before they have eroded their valleys 
 to so great a depth that the tops of the trees which skirt them can 
 not be seen peering above the general surface as one stands upon the 
 higher prairie levels. 
 
 The streams of Ringgold county, however, pass through it from a 
 northerly to a southerly direction, having at the northern border of 
 the county already attained considerable size, and in their passage 
 through it, have eroded their valleys so deeply that the full - grown 
 forest trees which skirt their banks can not be seen from the higher 
 prairie surface. Indeed they could not be thus seen in many cases 
 if they were three times as high as they are, for the valleys are 
 usually narrow, with somewhat abrupt slopes to the prairie level, and 
 from- one hundred to two hundred feet deep. 
 
 Timber is usually scarce in this county, but along the Platte, and 
 East and West Grand rivers there are considerable bodies of forest 
 trees consisting of oak, elm, maple, linden, cottonwood, hickory, 
 buckeye, black walnut, box elder, &c. 
 
 Most of the roads are excellent, being located upon the " divides," 
 and as the traveler passes over them there is very little upon which 
 the eye can rest to relieve the monotonous expanse of prairie ; and 
 if a stranger he is quite unconscious of the presence within the 
 range of his vision of these deep valleys with their wooded banks, 
 until he approaches to cross them, which being done they are again 
 hidden from view, and the course of the valley itself obscured by 
 the general undulatory character of the surface. 
 
 It is diSicult, if not impossible, to ascertain accurately the 
 depth of the drift deposit in this county, but it is probably not less 
 
REPORT OF STATE GEOLOGIST. 45 
 
 tban one hundred and fifty feet deep where none of it has been 
 removed by erosion. Indeed it can not be certainly known that it is 
 not fully as deep as the full depth of the valleys before mentioned, 
 for no other material appears upon the slopes, and the only 
 exposures of rock to be found in the county are a few small quarries 
 of upper coal - measure limestone near the Missouri border, on 
 section 19, township 67, range 29, together with a few similar 
 exposures iu the extreme northeast corner of the county. There 
 are at least five hundred and fifty square miles of this county upon 
 which no rocks appear except the very few boulders associated with 
 the drift. It will be thus seen that a geological examination of 
 such a county alone, disconnected from adjoining territory would 
 give very unsatisfactory results, except of the character of the 
 surface. In view of this a detour was made to the northward into 
 Union, Madison and Adams counties, thence southward into Taylor. 
 Examinations there, together with those within the county, leave no 
 doubt that the first stratified rocks beneath the drift - deposit in 
 Ringgold are the upper coal - measure limestone ; the inference from 
 which is that if coal is ever obtained here, it will be found at 
 considerable depth below the surface. It is not at all improbable 
 that oae or more beds of coal underlie the county, but if so, further 
 and more extensive examinations are needed to give even an 
 approximate estimate of the depth at which it may be found. 
 
 The county is so well drained that hardly a single pool can be 
 found within its borders, yet water is abundant in the streams, and 
 also easily obtained at a moderate depth anywhere upon the high 
 lands except upon the narrow ridges, and immediately upon the 
 slopes. The prairies are covered with a luxuriant growth of wild 
 grass, and the cultivated varieties succeed admirably. Consequently 
 this is destined to be an important one for stock - raising as well as 
 for purposes of general farming. 
 
 TAYLOR COUNTY. 
 
 Taylor county is similar in the general character of its surface to 
 those which adjoin it. It has rather more timber than Ringgold, but 
 not so much of either timber or stone as Decatur county. The 
 streams flow to the southward through it as in RinggoM, but they 
 
^Q REPORT OF STATE GEOLOGIST. 
 
 will not average quite so large, and their valleys are consequently 
 not qui CO so deep nor their slopes so abrupt. The county is per- 
 fectly draiaed by its rivers and creeks, so that not a marsh nor pond 
 was anywhere seen. These streams afford good water for stock, and 
 springs are not uncommon in depressions upon the prairies. Excel- 
 lent water is also readily obtained anywhere upon the prairies at a 
 very moderate depth. 
 
 Timber enough for present use can be found in the vicinity of the 
 streams, which rapidly encroaches upon the prairie where the fires 
 are kept out. These trees also grow rapidly when planted upon the 
 prairies. Hon. L. W. Hillyer, of Plattville, has some Cottonwood 
 trees about his residence which he had planted five years ago, and 
 which measure twenty -three inches in circumference at the root. 
 His method of propagating them is so peculiar and successful as to 
 deserve particular mention, and thorough trial by others. He 
 procured freshly cut poles of that wood from the timber, chipped 
 them with an ax at short intervals, and then planted them, end to 
 end in shallow trenches. Vigorous sprouts soon sprung from each 
 of the chipped places which grew much more rapidly than the young 
 trees which were transplanted with their roots at the same time, and 
 soon exceeded them in size. They have also a much more healthy 
 and thrifty appearance. Whether other trees may thus be propa- 
 gated, remains to be tested. It is very desirable that other trees, 
 particularly the White Maple, which grows vigorously, should be 
 extensively propagated, but the cottonwood grows more rapidly than 
 any other, and is consequently sooner available as fuel, althouch the 
 quality is not so good as that of most others. Mr. Hillyer thinks 
 that if he had planted ten acres in trees at the time he planted his 
 grove, he might now have drawn all his supply of fuel from that 
 source. 
 
 Considerable portions of this county, particularly the northeastern 
 and southwestern parts are destitute of stone. Several good 
 quarries are opened in the upper coal- measure limestone on the One- 
 hundred - and - two river in the vicinity of Bedford. There are also 
 a few exposures of the same rock along the river between Bedford 
 and the southern boundary of the State. In the northwestern part 
 
REPORT OF STATE GEOLOGIST. 4.7 
 
 of the county, on several points on the East Nodaway, above where 
 that river enters Page county, a blue argillaceous limestone is found, 
 and beneath it a fifteen - inch bed of coal is being worked on land of 
 Mr. J. R. Foster, section 29, township 70, range 35, which is thus 
 far the only bed of coal worked in the county. It was at first 
 believed that this bed of coal belonged to the upper part of the 
 lower coal - measures, but subsequent examinations leave no doubt 
 that it belongs quite within the upper series and is believed to be the 
 only bed which that series contains. Connected with this change of 
 opinion is also the belief that although other beds of coal may be 
 expected beneath the one now worked, they lie at considerable 
 depth. 
 
 The coal of Mr. Foster's mine is of good quality, and having a 
 large market for it, he finds it profitable to have it mined although 
 the bed is so thin. 
 
 Mr. Edwin Houck is making a good quality of lime from his 
 quarries at Bedford, for which he finds a ready market, as well as 
 for his quarry - rock. 
 
 The soil of Taylor, is of the same excellent quality as that found 
 in the counties before named. 
 
 The marketable products of its citizens consist at present of live 
 stock, for which buyers reach them from both the eastern and 
 western borders of the State. 
 
 PAGE COUNTY. 
 
 Within the memory of some now living the growing wheat crop of 
 the Genessee valley was watched with lively interest by the whole 
 country, because success or failure there eifected the market far 
 and near. This was before the Great West had begun to send 
 forward for the world's consumption, her surplus store amounting to 
 millions of bushels of grain every year. That vallay, is still fertile 
 and beautiful, but now, in the growing greatness, of our country, it 
 has dwindled into insignificance compared with the fame it once 
 possessed. Other valleys have been settled and cultivated as the 
 tide of civilization rolled westward, which vie with that in every- 
 thing that makes a region desirable, but being themselves in the 
 
48 REPORT OF STATE GEOLOGIST. 
 
 midst of bouadless productivenes, their excellence has become 
 known only to the passing traveller, and to those who dwell there. 
 Thare are yet others in our State of surpassing beauty and fertility, 
 which have only just begun to be settled, and which will in a few- 
 years produce more bread, and be the seat of a greater number of 
 happy homes than the far famed valley of the Grenessee. 
 
 Page county possesses one of these lovely regions in the valleys 
 of the Nodaways. These streams ought to receive separate names, 
 but in the meagre nomenclature of the pioneer, each large branch of 
 a stream retained the name of the principal one, with the distinctive 
 prefix East, West, or Middle, as the occasion required. Thus we 
 have a multiplicity of Chariton, Grand, One - hundred - and - two, 
 Nodaway, Tarkeo and Nishnabotony rivers. The West Nodaway 
 stretches entirely through the county from north to south, a distance 
 of nearty twenty - five miles, but which is only a small portion of its 
 entire length, while the Bast Nodaway has a length of only about 
 twelve miles in this county, having entered it near the middle of the 
 east line, from Taylor, which received it in turn from Adams : but 
 more particular reference is here made to the West Nodaway. The 
 character of the approaches to this stream is somewhat different from 
 those which drain the counties to the eastward of it. The stream itself 
 lies about as far below the general prairie 'level as those of similar 
 size in Taylor county, about one hundred and fifty feet, but the val- 
 ley slopes are more gradual, commencing about a mile from the 
 stream on either side. These slopes are themselves undulating like 
 the higher prairies, the drainage system of which is here repeated in 
 miniature. Shallow, grassy ravines come down to the stream at 
 intervals, gradually diminishing branches of which extend outward on 
 either side and up the slope, multiplying and draining the land com- 
 pletely, and giving it a very pleasing appearance when viewed from 
 the opposite side. This is the general character of the valley in its 
 whole extent through the county, but yet it possesses diversity 
 enough to make it pleasant for the eye to rest upon it at every point. 
 Although the eastern part of Page county contains more timber than 
 any other of the southern tier, thus far seen west of Decatur, yet 
 these approaches to the Nodaway are principally prairie slopes, which 
 
REPORT OP 8TA.TE GEOLOGIST. 49 
 
 allow their features to be seen with admirable distinctness. Imme- 
 diately bordering the stream, more or less timber is always found. 
 Sometimes, it is true, it amounts to but a very narrow belt, but at 
 other places it is a quarter of a mile or more in width. Beside this, 
 where its tributaries meet it, as well as at some other points also, still 
 larger groves extend upward upon the slopes; and in the space 
 between the East and West Nodaways, opposite Clarinda, there is a 
 body of timber four miles in width. 
 
 At this season of the year (last of July) the ripened heads of one 
 species of prairie grass gives the surface a sere and barren aspect in 
 the distance, and in looking down upon this valley one sees the 
 immense fields of green luxuriant corn, and yellow, ripened grain, 
 standing upon the surface like rectangular oases in a desert of grass. 
 This desert is one only in appearance, for it only needs the plow to 
 convert every square rod of it into fields fertile as those which are 
 now there smiling with a plentiful harvest. 
 
 The other rivers of the county are cwo' small streams, the East and 
 West Tarkeo, both of which traverse it from north to south ; and the 
 East Nishnabotony, which crosses the northwest corner. A narrow 
 belt of timber skirts the latter river ; a little is also found on the 
 East Tarkeo, but from the latter stream to the west line of the coun- 
 ty, stretches one almost unbroken, but deeply undulating prairie, all 
 of which is as fertile as any soil in the State, as occasional fields of 
 grain will testify, which are being cultivated wherever a grove of 
 trees forms the nucleus for a settlement. 
 
 Limestone of good quality for building purposes is quarried at 
 various points along the Bast and West Nodaway, from Hawleyville 
 in the east part of the county, to the Missouri line'; a very good sup- 
 ply being obtained within a few miles of Clarinda. A persistent 
 ledge of a few layers, of a hard, ponderous, bluish limestone, two or 
 three feet in thickness, is found cropping out at frequent intervals on 
 the prairie - points, and in small streams bordering the East Tarkeo. 
 It shows itself a little above the level of the narrow bottom border- 
 ing the stream, and extends quite through the county from north to 
 south, and dipping to the southward at about the same rate that the 
 water falls in the stream, it appears at about the same elevation 
 7 
 
5Q EEPORT OF STATE GEOLOGIST. 
 
 above it at all points. This stone seems well adapted to all the pur- 
 poses for which stone is usually required, except the manufacture of 
 lime. Thus far efforts with ic in this direction have failed, although 
 it seems to be composed principally, at least, of carbonate of lime. 
 It very much resembles in physical characters the rock which has 
 been successfully used in Davis county for the manufacture of 
 hydraulic cement. 
 
 The only bed of coal yet found in this county is worked at various 
 points near Olarinda, and is identical with the one which is worked 
 at Quincy in Adams county, and also on Mr. Foster's land in the 
 northwestern part of Taylor county. 
 
 The soil is everywhere fertile, and almost everywhere covered with 
 a luxuriant growth of grass. Along the valleys of the rivers of this 
 county, the "blue joint," one ot the most nutritous of the wild gras- 
 ses, is very abundant, making it one of the best natural stock-raising 
 regions in the world. Large numbers of cattle, horses and sheep are 
 now raised by the citizens of the county, but thousands of acres of 
 this excellent grass dies annually, hardly a mouthful of which is con- 
 sumed. The streams of the county afford abundant water for stock, 
 and pure cold water can be obtained at a moderate depth almost any- 
 where upon the prairies, as well as in the valleys. Beside which, 
 excellent springs are not unfrequently found along the slopes of the 
 streams. 
 
 FREMONT COUNTY. 
 
 This county is more distinctly marked in its surface features 
 than any of those between it and the Des Moines river, which 
 difference is due to two distinct causes not possessed by any of those. 
 The first of these causes is the great Missouri river which courses 
 along its western border, and which, aside from the effects produced 
 in its own immediate vicinity, has also bad a modifying influence upon 
 the drainage of the county by the Nishnabotany and its tributaries. 
 The second cause is the existence over a great part of the county of 
 a peculiar deposit which forms the soil where it exists, as well as 
 much of the material beneath it, all resting upon the drift, the finely 
 pulverized upper portion of which forma the soil in other portions of 
 the State. 
 
REPORT OF STATE GEOLOGIST. 51 
 
 This deposit has been called by Prof. Swallow, State Geologist of 
 Missouri, " the bluff deposit, " which term will also be used in these 
 communications from the field. It is composed of very finely 
 comminuted silicious matter, with much clayey and limy material, a 
 part of the latter having formed into stony concretions, from the 
 size of a nut to a forty pound shot. With the exception of these 
 concretions, which form a very inconsiderable part of it, the whole 
 mass is very uniform in its color and composition from top to 
 bottom, even where it is more than two feet thick. It is of a 
 slightly yellowish ash color where it has not been rendered darker 
 by decomposed vegetable matter resulting from the profusion of 
 grasses and plants, whjch grow upon it in every favorable situation. 
 
 Resting upon the drift, which it will be remembered contains the 
 water - worn pebbles, boulders and sand, it has of course been formed 
 at a subsequent period, and bears within itself the evidences of its 
 origin in a fresh water lake which was doubtless anciently an 
 expansion of the Missouri river. * 
 
 There is reason to believe that this deposit does not extend 
 eastward of the Nishnabotanys in Fremont county, but its exact 
 limit in this direction is not clearly defined, from the fact that the 
 fine material of the upper portion of the drift forms a soil almost 
 identical in appearance in most places, with that formed by the bluff 
 deposit, supporting the same profusion of grasses and plants, and 
 presenting but, little to the eye of the casual observer to indicate a 
 change of composition in the soil - material. It is along the border 
 of the Missouri river bottom, and in excavations such as cellars and 
 wells, that the strange peculiarities of this deposit are seen. Exca- 
 vations are made in it with less labor than in the drift, and when 
 moist a strong man can thrust a spade into it without difficulty. Yet 
 wells dug in it and walled only just above the water line, remain 
 unchanged for years, the sides showing the spade marks upon them 
 as when they were first dug. Very good cellars are also made in it, 
 the perpendicular banks of which remain without a wall or other 
 support, and sometimes even the steps are carved out of it, which 
 when dry, as it usually becomes, remain serviceable for a long time 
 with a little care. 
 
 * See the article entitled "Lakes of Iowa, Past and Present, " on another page. 
 
52 REPORT OF STATE GEOLOGISl. 
 
 Bordering the Missouri river bottom — which, with the exception 
 of a narrow belt of timber along the river, is in this county a nearly 
 level prairie from three to six miles wide — the bluft' deposit ends as 
 abruptly as the rocky cliffs of the Mississippi, and viewing the 
 fantastic shapes into which it has been carved by fluvatile and 
 meteorological erosion, one can hardly rid himself of the idea that 
 these too, are supported by a frame - work of rock. But this is not 
 the case, for not a stone of any kind is to be found in the whole 
 mass save the limy concretions above referred to. Along the base of 
 these bluffs between the northern and southern line of the county, 
 ledges of the upper coal - measure limestone and sandstone are found, 
 resting upon which a comparatively thin deposit of drift is seen 
 with its boulders, gravel and sand, which in turn bears upon itself 
 the bluff deposit. This towers up above the drift in some places 
 more than two hundred feet, and upward of two hundred and fifty 
 feet above the general level of the river bottom. 
 
 Frequent springs of pure cold water issue from the drift at the 
 base of the bluff deposit, and there are also evidences of the former 
 existence of many which have ceased to flow or that have sought 
 other channels. These springs have doubtless had some effect in 
 producing the peculiar outline which the face of the bluff presents, 
 particularly in forming the beautiful little natural ampitheaters, 
 containing from a few square rods to an acre, covered with box - elder 
 and other trees, opening toward the river, but nearly surrounded 
 by high buttresses and undulating precipitous slopes which are 
 covered sparsely with prairie grass to their tops. From some of 
 these, springs still issue, making them delightful nooks in which to 
 hold pic-nics, or for the matter-of-fact farmer to shelter his stock. 
 In many places the bluffs are so precipitous that they appear almost 
 perpendicular, but this is far from being the case, since appearances 
 of this kind are always deceptive. The steepest' fronts will average 
 less than an angle of forty - five degrees with the horizon, and the 
 boldest and most precipitous one we found, upon which the grass 
 was growing, when tested with the clinometer proved to be only fifty 
 degrees. There are occasional places in some of the more promi- 
 nent fronts where the material has fallen down, which present bared 
 faces for a short distance, which are in reality nearly perpendicular, 
 
REPORT OF 8TA.TE GEOLOGIST. 53 
 
 and these stand there year after year, with little or no change, 
 becoming so dry that no grass can grow upon them, and giving the 
 appearance in the distance of a rocky cliff. There is a peculiar 
 rounding to the summits of these bluflfs many of which resemble the 
 artificial mound raised by a departed race of Indians upon those 
 which border the Mississippi, but their great number would undeceive 
 one in this respect if their shapes were not more varied, and their 
 ridges and slopes also did not partake of the same character. 
 Being destitute of trees upon their summits, and stretching north- 
 ward and southward so far as the eye can reach, they present a 
 strange and impressive aspect quite different from that produced by 
 any other formation in the State. 
 
 Proceeding inland from the great river, the surface becomes much 
 less broken although the material is the same, and a great portion 
 of that which is not occupied by fertile farms, is covered by a 
 thrifty growth of timber; and approaching this county from the 
 prairies which lie to the eastward of it, one sees for the first time 
 since leaving Decatur county, the horizon serrated with forest trees 
 growing upon the high lands and slopes. 
 
 The Missouri river bottom is, in this county at least, somewhat 
 different in character from that of tl^e Mississippi. Here are none 
 of the definite terraces which are often seen there, and the whole is 
 more nearly level from the river to the bluff. The greater part of it 
 is prairie, and much of it is never reached by the highest floods of 
 the river, perhaps excepting those which occur at intervals of many 
 years. The soil here is of the most extraordinary fertility. Wells 
 dug in it show a depth of more than ten feet, every inch of which is 
 as fertile as that turned by the plow. There are some farms upon 
 this bottom which have yielded a bountiful crop of corn every year 
 for fifteen years, without rotation of crops, without manure, and 
 almost without care. The formation of this bottom land was long 
 subsequent to that of the bluff deposit, from which much of its 
 material was derived, which, as already explained, was deposited at 
 a period subsequent to that in which the drift with its own product- 
 ive soil was formed. Thus we perceive that this county presents 
 excellent, and, indeed, remarkable examples of soil of diluvial, 
 
54 REPORT OF STATE GEOLOGIST. 
 
 lacustrine, and fluvatile origin, each succeeding the other in order 
 of time ; all of which are also of remarkable fertility. 
 
 The northeastern and southeastern portions of Fremont county 
 are nearly all prairie, but the region along the Nishnabotany and its 
 tributaries, as well as a great part of the county west of that river, 
 furnishes much more than the average amount of timber. In the 
 description of Page county, considerable space was devoted to a 
 description of the valley of the Nodaway, but the great length of 
 this letter makes it necessary to close it ^.ithout doing full justice to 
 the valleys of the Nishnabotany and its tributaries. A few words, 
 however, must be said concerning its general features, and these will 
 be confined to the West river, which extends from the northern to 
 the southern line of the county, almost directly through its middle. 
 It is a larger stream than the Nodaway, and its valley occupies a 
 much wider area, but nearly all that was said of that valley is also 
 applicable to this. The approaches to the stream, however, are 
 longer and more gradual; the valley is wider from the highest land 
 on either side, averaging four miles or more in width, and then it has 
 also a distinct bottom, which is not so marked a feature of that of 
 the Nodaway. 
 
 A dweller by the Mississippi, viewing this valley from the high 
 lands for the first time, would be likely to mistake the real character 
 of its bottom, for it is not in reality so flat as those he is accustomed 
 to see there. Far the greater portion of it is never reached by the 
 highest floods which swell the river in wet seasons. Standing near 
 the river, and looking toward the slopes on each side, the bottom land 
 will, in most cases, be seen to rise without a terrace towards them, at 
 the rate of about forty feet in the mile, the distance from the foot of 
 the slope to the river being often as much or more than this. There 
 are occasional low places which are reached by the high waters, but 
 most of them are drained when the waters subside, leaving no pond, 
 and the surface becomes covered with grass every year. The soil of 
 these places, and that closely bordering the stream is composed of 
 the disturbed material of the blufi" deposit, while the higher portions 
 of the bottom land are composed of unaltered bluff material like the 
 high lands along the border of the valley and to the westward of it. 
 The view of this valley from the highlands is everywhere so delightful 
 
REPORT OF STATE GEOLOGIST. 55 
 
 that it is not easy to select any one region -which greatly excels 
 another in this. respect, but no person capable of appreciating the 
 beautiful can pass over the road from Sidney to Hamburg without 
 being thankful that his eyes were permitted to rest upon scenes so 
 lovely as those which meet his view all the way. 
 
 The deep drift in the eastern part of the county, and the deeper 
 bluff deposit of the middle and western portions have covered from 
 sight all, or nearly all the stratified rocks which exist beneath it, 
 except along the base of the Missouri river bluffs, the most southern 
 exposure of which is seen on the town lot of Mr. Allen near his 
 saw -mill in Hamburg. This is now nearly obscured by grading, but 
 enough was seen to indicate several layers of upper coal - measure 
 limestone with marly partings, resting upon a fine grained, micaceous 
 sandstone, at an elevation of thirty or forty feet above the general 
 level of the river bottom. Following up the base of the bluff along 
 the bottom road to Plum Creek the exposures, particularly of the 
 limestone, become more frequent, and afford good quarry - rock. At 
 about two miles above Plum creek, and extending thence some two 
 miles further along the base of the bluffs, there are very full 
 exposures of limestone, which afford the finest and most extensive 
 quarries yet seen west of Madison county. The stone closely 
 resembles those obtained from the quarries of that county, in quality 
 as well as in the excellence of its lime. It can be obtained here 
 in almost any desired quantity, and with not greater than the 
 ordinary amount of labor in quarrying. 
 
 Near the residence of Mr. John Wilson, on Section 14, township 
 70, range 43, this gentleman kindly pointed out a place where a ten 
 inch bed of coal has been exposed by excavation ; an examination 
 of which, together with the strata above and below it, leaves 
 but little, if any doubt, that it is. a continuation of the same bed 
 which is being worked in Adams, Taylor and Page counties. It is 
 hardly probable that this bed will be found thick enough to be prof- 
 itably worked in this county. 
 
 The brick made in this county are of very fair quality, the clay 
 for which was obtained from the drift, at the base of the bluff 
 deposit, at the only yard where it was examined. The bluff 
 material would itself probably make very fair brick were it not 
 
5Q REPORT OF STATE GEOLOGIST. 
 
 that the small limy concretions which it contains, are changed to 
 to quick - lime when the bricks are burned, and then when exposed 
 to moisture the slaking of the lime bursts them. 
 
 MILLS COUNTY. 
 
 The counties of Mills and Fremont are so similar in geological 
 character, as well as in those topographical features which 
 distinguish them from the counties lying to the eastward of them 
 that much of the description of one would be equally applicable 
 to the other. In view of this, and of the unusual length of my 
 letter on Fremont county, some of the topics discussed therein will 
 be continued in this, and others will now receive attention which 
 were omitted in that. 
 
 Although Mills county seems to contain proportionally a little 
 less timber than Fremont, yet it has more than the counties east- 
 ward of those on the Missouri watershed will average; the principal 
 portion of which is found in the western half of the county. 
 Wherever the fires are kept from the prairies the young timber 
 grows up with great rapidity, so that one frequently sees considera- 
 ble bodies of forest trees of the various kinds common to the State, 
 large enough to use for fuel, which have grown up since the country 
 was settled. These trees, as ^^ell as the osage orange also, succeed 
 well when planted upon the prairies that rest upon the bluif deposit, 
 as well as those which rest upon the drift. 
 
 The beautiful and fertile valley of the ^ishnabotany extends 
 through the county from north to south, and is almost identical in 
 character with that part of it lying in Fremont, and the smaller but 
 no less beautiful valleys of Silver and Keg creeks traverse large 
 portions of the northern and central parts. These valleys with 
 their tributary depressions are not as deep as the valleys of similar 
 streams are in some of the counties to the eastward and the 
 approaches to them are so gentle that they can all be as easily 
 cultivated as the more level land. This character of the valleys 
 began to be distinctly perceptible upon reaching the Nodaway, and 
 at the same time, that clearly defind ocean -like horizon of the 
 prairie level observed in Wayne and elsewhere began to be less 
 distinct, and these changes, particularly the former, are more readily 
 
REPORT OP STATE GEOLOGIST. 57 
 
 recognized, as one passes westward into Fremont and Mills counties; 
 the nearest approach to a definite prairie horizon being seen in 
 the northern part of Mills. The eastern border of the bluff deposit 
 was not recognized in this county, and it doubtless extends over the 
 whole surface, except where the streams have eroded their valleys 
 through it, reaching the drift with its gravel sand and boulders 
 beneath, but by this means it was seen to be much thinner in the 
 western part of the county. 
 
 The Missouri river bottom extends the full length of the county 
 as in Fremont, the character of it being similar, and the width 
 averaging about the same, for the river nowhere approaches the 
 bluffs in either of these counties. The bluffs of Mills, generally 
 slope more gradually to the bottom lands, and are more frequently 
 wooded than in Fremont ; and where the timber does not exist the 
 slopes are more thickly covered with grass. This results, not from 
 any change in the character of the material, but wholly in conse- 
 quence of the more gradual sloping of the hills, thus retaining the 
 moisture ; for where the peculiar material of which they are formed 
 is exposed in such prominent and precipitous masses as are some- 
 times seen, it becomes too dry to support vegetation; yet under more 
 favorable circumstances every part of it, even when thrown out of 
 deep wells, produces a luxuriant growth, both of plants and trees. 
 Thus many of the bluffs of Mills county are wooded upon their 
 slopes, while their prominent, rounded summits are destitute of trees, 
 reminding us of the waning locks of our honored sires. 
 
 The material composing the bluff- deposit has some physical char- 
 acteristic which are very remarkable. One of the most striking of 
 which is the constancy with which it remains unchanged by atmos- 
 phere or frost, in any shape which has been given to it by natural 
 or artificial forces, while it can be readily excavated by the spade 
 alone. It is this which maintains the bluffs in their strange and 
 peculiar shapes as unchanged in form as those are in other parts 
 of the country which are supported by a framework of rocks. 
 Wells dug in it do not need walls above the water line ; stock 
 shelters dug in the hillsides are serviceable for many years ; 
 roads upon it become hard and do not wash easily by the rains, 
 8 
 
58 REPORT OF STATE GEOLOGIST. 
 
 and thus the roads of this region are among the best in the 
 State, for there is not a stone to jar the wheels, nor deep ruts to 
 impede them. It dries so readily that lime and pottery kilns are 
 dug out in the prominent points, and used as T\'ell and as long 
 without walls, as they can be with them in other places. And yet 
 the soil formed from the same material will endure a drouth as well 
 as any other, and those who till it claim that it is better than the 
 average in this respect. The water of springs and creeks run 
 perfectly clear upon it much of the time, and where they have finally 
 cut their narrow channels down, the banks remain precipitous and 
 the ravines very short beyond the issuance of the spring. 
 
 All that was said of the excellence of the soil of Fremont county 
 is also applicable to that of Mills, and the stratified rocks of both 
 counties bear the same relation to the productive coal - beds of the 
 Des Moines River Valley. Large quantities of excellent limestone 
 are found along the base of the bluffs in the nouthwestern part of 
 the county. The exposures are almost identical in character with 
 those in the northwestern part of Fremont, and the quality of the 
 rock, about the same. A couple of quarries of limestone also exist 
 on Silver Creek, in the south part of the county, and in the north- 
 eastern corner, there are considerable exposure of sandstone, some 
 of which is quarried by Mr. Peter Cooper, and wrought into various 
 shapes for building purposes. 
 
 Some of the layers of limestone both in Mills and Fremont 
 counties, closely resemble, in physical characters, a stone which has 
 been successfully used in Davis county for the preparation of 
 hydraulic cement. Even if these should be found upon trial to 
 produce a good quality of that valuable article, any person contem- 
 plating the manufacture of it, should satisfy himself of the existence 
 of a large and constant supply of the stone, and also that its 
 character is uniform ; for that of the various localities which furnish 
 the best cement, is almost never identical in composition, and some- 
 times they are widely diiferent in this respect, while furnishing 
 equally good cement. It thus becomes necessary that the stone of 
 each locality should be studied and experimented with independently 
 of others. 
 
 At various points along the base of the bluffs, both- in Mills and 
 
REPORT OF STATE GEOLOGIST. 59 
 
 Fremont counties, where springs issue or have issued in former 
 times, considerable ' masses of porous stone are seen, which are 
 always of limited extent, and have been formed entirely by the 
 spring water giving up a portion of its lime upon coming ifi contact 
 with the atmosphere. This is found in various parts of the world, 
 and is called calcareous tufa. Another curious fact observed there is the 
 formation of small masses of sandstone by the same natural process, 
 the lime from the water forming a cement as it has percolated through 
 the sand often found in the drift, at the base of the bluifs. At a 
 point not far from St. Mary's, in Mills county, a mass of natural 
 " concrete " was found, formed in the same manner. This mass was 
 identical in appearance with that used in the construction of "con- 
 crete houses, '" so much recommended a few years ago. The granite 
 and greenstone pebbles it contained, prove it to have been derived 
 from th€ drift. But these substances are merely curious, and not of 
 any economic value, and are only mentioned here to correct the 
 impression that they are parts of large masses of stone extending 
 beneath the surface. 
 
 The brick manufactured in Mills county, are very good, far better 
 than any seen in the prairie region lately passed over. The material 
 from which they are made at Glenwood, is taken from the base 
 of the bluff deposit, four or five feet of which, at the base, contains 
 more clay than that above. It is the practice there to mix the whole 
 together, since they find that the upper portion has not 'coherence 
 enough to hold the bricks together while drying, and the lower 
 portion cracks by the same process. 
 
 POTTAWATTAMIE COUNTY. 
 
 The great thoroughfares of the earth, around which wealth and 
 civilization cluster, and along which property is always most valuable, 
 are not arbitrarily located by man, but their routes are in a great 
 measure determined by geological features, themselves the result of 
 geological causes which completed their operations long before he 
 was created. It is from such causes as these that the continents 
 have their outline, mountains range their elevation, the sea its 
 bounds, and the rivers their volume and direction ; and now, while 
 the rapid tide of civilization is setting across the continent, requiring 
 
gQ REPORT OF STATE GEOLOGIST. 
 
 the establishment of new and more artificial lines of intercommu- 
 nication, similar circumstances, rssulting also from the operations of 
 nature herself, and therefore immutable, are rapidly making Potta- 
 wattamie county one of the most important, as it is in superficial 
 area one of the largest counties in the State. The great Missouri 
 river which flows along its western border will never cease to bear 
 the burthens of its commerce, but the commercial importance of 
 the river to this county is much diminished by the fact that the 
 latter lies directly in the course of one of the great lines of railway 
 which are soon to connect the Atlantic with the Pacific ocean ; and 
 the further fact that natural causes will tend to ■ converge some of 
 the proposed Iowa lines of railway to a point within it, and near the 
 Missouri river. The principal of these natural causes — and none 
 other will be discussed — consists in the peculiar and deep erosion 
 of the valleys of the larger tributaries of the Missouri river which 
 have their confluence with it to the northward, which render it nearly 
 impracticable to build the proposed east and west lines directly 
 across them. Upon reaching these from the eastward, they must 
 bend their course southward along the valleys of these streams in 
 order to reach the Missouri river with facility, or to connect with 
 the great Pacific railway opposite Council Blufis. These circum- 
 stances will probably require them all, either to pass into this 
 county, or to approach it so nearly as to render a connection with 
 those within it desirable. 
 
 These advantages, although remote in their origin aud indirect in 
 their characters, are of immense importance, and would in time cause 
 an unfruitful land to be desirable, but in addition to these, Potta- 
 wattamie county has fully an average of inherent natural advan- 
 tages, not the least of which is the possession of more than half a 
 million acres of as fertile and tillable soil as can be found in the 
 State. 
 
 That of the higher lands is composed almost entirely of the bluff 
 deposit, which extends nearly or quite to the east line of the county. 
 The greater part of its surface is prairie, the grasses of which are of 
 the more nutritious varieties, rendering it one of the most desirable 
 grazing regions to be found. The beautiful valley of the "West 
 Nishnabotany passes through its eastern portion frpm north to south, 
 
REPORT OF STA-TE GEOLOGIST. Ql 
 
 •which is also the general direction of all the other streams that drain 
 the county. This is done so completely that hardly a pool of 
 stagnant water can be found within its borders ; yet the smallest 
 of the streams, even in the present dry season, aiford an abundance 
 of water for stock. Excellent wells can be obtained almost every- 
 where, except in the immediate vicinity of the bluffs, and springs of 
 pure cold water are aften found along the banks of the streams, 
 although often no stone or tree is near them to mark the spot. 
 
 Wood is more abundant in the western than in other parts of the 
 county, where large bodies of young timber are rapidly growing up. 
 
 Limestone of good quality for lime, and also for building pur- 
 poses is found in township 74, range 40, and large quarries of excel- 
 lent limestone are found three- miles eastward, and also six miles 
 northward from Council Bluffs. 
 
 At various places along the base of the bluffs bordering the 
 Missouri River bottom, large masses of coarse sandstone and con- 
 glomerate, as well as of light porous limestone are frequently seen, 
 which appear in some cases to be parts of regular ledges of rock, 
 but which are in reality of only limited extent, and have been 
 formed by the deposition of lime from the spring water which issues, 
 or has issued near them. The porous limestone has been formed 
 wholly from the limy material deposited from the water upon 
 reaching the atmosphere, and although impure, a similar substance 
 has been used to make lime in some parts of the country, in the 
 absence of better material. The sandstone and conglomerate have 
 been formed by the percolation of the limy water through the beds 
 of sand and pebbles belonging to the drift, cementing their particles 
 together while they remained in the exact position in which they 
 were deposited. Thus when these beds of loose material were 
 deposited in horizontal layers, they retained that position when con- 
 solidated, and now present the appearance somewhat of rocky ledges. 
 Some of these masses are quite hard, but the cementing material 
 being merely a carboaate of lime, they are probably not so strong 
 as the same mass would in time become if prepared with quicklime ; 
 for in that case, a part at least of the cement would be a silicate of 
 lime, which is stronger and more indestructible. 
 
g2 REPORT OF STATE GEOLOGIST. 
 
 The question is often asked by the people, "do stones grow?" or 
 in other words, "are they now in process of formation by increase?" 
 The reply is almost invariably in the negative, for the question ia 
 usually asked in relation to the stones as we usually see them, which 
 not only do not grow, but like everything else without life have a 
 constant tendency to disintegration and destruction. Some rocks, 
 such as some of our boulders, are believed to have had their origin 
 as such by fire when the foundations of the earth were laid, or by 
 subsequent fusion, but all the strata of rock in our State at least, 
 had their origin at the bottom of the sea, ages subsequent to the 
 formation of most of the granite rocks, from which the majority of 
 our boulders are derived. The ,sea of course then covered the 
 ground where we find them, and similar strata are doubtless now 
 being formed beneath the sea, but human eyes can never actually 
 witness the operation. These masses are, however, an exception to 
 the rule, and are now actually in process of formation beneath our 
 eyes. None of these adventitious rocks are of any considerable 
 value, but are yet very interesting to those who are fond of studying 
 the operations of nature. 
 
 These springs, although containing so much lime, are nevertheless 
 quite wholesome, and some of them, two or three miles above Council 
 Bluffs, are among the largest in the State, the waters of which, if 
 collected, might probably supply the city until the increasing popu- 
 lation should render them inadequate for that purpose. 
 
 The peculiar bluffs mentioned as so striking a feature in Fremont 
 and Mills counties also extend all the way through Pottawattamie 
 county, bordering the broad river bottom. The extraordinary deposit 
 of which these bluffs are formed reaches its typical development in 
 Pottawattamie, and a point near Council Bluffs was selected by Dr. 
 Owen from which to prepare an engraved view of the bluffs which 
 embellishes his geological report to the General Government. . 
 
 Faint traces of glacial action were observed upon the upper layers 
 of limestone in the quarry now worked by Mr. Merritt, six miles 
 north of Council Bluffs, but they are not so distinct as those seen 
 in Mills county, and also a mile south of Omaha, all of which are 
 described on other pages. 
 
REPORT OF STATE GEOLOOIST. g3 
 
 Very little can yet be said in reply to the great questions constant- 
 ly asked by the people, " Have we any coal or other valuable mate- 
 rial beneath our fertile soil?" The probability of finding any other 
 valuable mineral substance besides coal in this county is so slight 
 that little or no especial attention is given to that branch of investi- 
 gation ; and all that can now be said upon the subject of coal in addi- 
 tion to what has been said in the introductory pages, is that it is bare- 
 ly possible that the bed now worked along the Nodaway may be 
 found in the western part of Pottawattomie county ; but if found it 
 will doubtless be thin' and of little value. 
 
 MONTGOMERY COUNTY. 
 
 Montgomery partakes of the character of both Page and Mills 
 counties, which it adjoins, which have been before described. Apart 
 of its soil is composed of the bluff deposit, and a part of it of the fine 
 material of the drift. The division between these two varieties, seems 
 to be along the valley of the Nishnabotany. Yet this is always dif- 
 ficult to determine from appearance alone, and in this county at least, 
 the soil is equally fertile in most cases. All that has been said of 
 the valley of the Nodaway in Page county, and that of the Nishna- 
 botany in Mills and Fremont is, to a great extent, applicable to Mont- 
 gomery ; for both of these beautiful valleys extend entirely through 
 the county from north to south. It is well drained throughout its 
 entire extent, like all the region round about it. It is well watered 
 also by its streams, and along the larger ones a considerable amount 
 of timber is found, the young growth of which rapidly encroaches 
 upon the prairies that are not annually burned. Pure, wholesome 
 water is obtained without difficulty at a moderate depth almost any- 
 where upon the high lands and in the valleys. 
 
 Limestone is found in considerable quantity at various points along 
 the Nishnabotany in townships seventy - two and seventy - three, from 
 the quarries of which the country around is supplied with lime and 
 building rock. It is also found in a number of places in the north- 
 eastern township of the county. A coal mine has also been worked 
 in this part of the county, the bed being about one - and - one - half 
 feet thick, and is doubtless the same one which is found near Quincy 
 in Adams county, which is about ten miles distant from that point. 
 
64 REPOKT OF STATE GEOLOGIST. 
 
 The same bed may probably be found at other points in the north- 
 eastern part of Montgomery, particularly in the vicinity of the mine 
 which has been worked. In an easterly and westerly direction from 
 that point, it will probably be found not to vary much from a level 
 with it, but to the southward the dip coincides pretty nearly with the 
 fall of the Nodaway. Along the slopes to the valley of the Nisbna- 
 botany a heavy bed of sandstone appears at various points, which is, 
 however, too soft to be used as stone, except in some instances where 
 iron is the cementing material. In such cases, irregular layers of 
 very hard, dark - colored stone are found in it, which will serve a 
 very good purpose for walling wells, in the absence of better mate- 
 rial. 
 
 Upon the first examination of this sandstone it was found to rest 
 unconformably upon the upper coal - measure limestone, and was sus- 
 pected to be of Cretaceous age, and the provisional name of "Nish- 
 nabotony sandstone" was applied to it. Subsequently it has been 
 proved to belong to that age by the discovery of characteristic fossil 
 leaves in the exposure within the village of Red Oak. 
 
 At the base of this sandstone, as seen on land of Mr. Johnson, 
 section 2, township 72, range 38, a bed of clay is found which is a 
 mixture of a dark red ochery clay with that of nearly a white color. 
 The latter has been tested for the manufacture of common pottery 
 and pronounced to be the best yet fcund in the southwestern part of 
 the State, and judging from its appearance, this is probably correct. 
 Clay of a reddish color, and doubtless the same bed, is also seen in 
 the hillside near Stover's Mill on the Nishnabotany, a couple of 
 miles below Red Oak. This clay, witlj the exception of its ochery 
 ingredient, is similar to the beds of fire - clay which underlie the beds 
 of coal in the eastern part of the State, and it is not improbable that 
 a thin bed of coal may yet be found in connection with this, but 
 there is little hope that it will prove, if found, of sufficient thickness 
 to be profitably worked. Mr. J. B. Packard, of Red Oak, exhibited 
 some material which he had used for paint, having the appearance of 
 the clay above mentioned, but containing a much greater proportion 
 of ochre than any before seen. It was obtained from his land near 
 Frankford, in this county, where it is found in considerable quantity. 
 It has been used for painting barns and out - houses for a number of 
 
REPORT OP BTA.TE GEOLOGIST. g5 
 
 years, and seems to give a good body to the paint, and resembles, 
 when applied, the material known as "Blake's fire - proof paint." It 
 is of a dark - red color, suitable for bridges and barns, but is too 
 sombre in appearance for that cheerfulness which should characterize 
 our dwellings. 
 
 The soil of Montgomery county is of that excellent quality which 
 prevails in this part of the State, and it needs only the extensive 
 planting of forest trees, and railroad - communication, to make it as 
 beautiful and prosperous as can be desired. Even now many neigh- 
 borhoods give evidence of wealth and prosperity in their well - culti- 
 vated farms, large herds of cattle and comfortable homes. 
 
 CASS COUNTY. 
 
 Cass, although only the second county from the Missouri, is yet 
 the most easterly one of the third tier which is wholly upon the 
 watershed of that river. 
 
 The East Nishnabotany does not take its rise in this county, but 
 it nearly loses its identity here by its subdivision into Indian, Camp, 
 Buck, Turkey and Troublesome creeks, while Seven - Mile and Six- 
 teen - Mile creeks form the head waters of the Nodaway, and com- 
 plete the drainage of the county, which is accomplished in the same 
 thorough manner as that of those which adjoin it. 
 
 The Nishnabotany retains its broad, beautiful valley as far up as 
 the vicinity of Lewis, the county - seat, where it passes for the dis- 
 tance of a few miles through a narrow space between the gently- 
 sloping hills, without the broad bottoms which characterize it below. 
 Above this, the valley is found to widen again, and continues thus 
 as tar up as the sub - division of the river into the creeks before 
 mentioned. 
 
 Interesting as the characteristic- portion of the valley of this river 
 is, the vicinity of Lewis is no less pleasant, with its wooded slopes 
 and gentle declivities, which, together with the valleys of the creeks 
 in the neighborhood, give a pleasing diversity to the scenery around. 
 
 The soil of Cass county is of that abundant and uniform fertility 
 
 which characterises this portion of the State, and some of it has the 
 
 appearance of being a little warmer, from a slight admixture of sand, 
 
 doubtless derived from the cretaceous sandstone before referred to as 
 
 9 
 
gg REPORT OF STATE GEOLOGIST. 
 
 existing in Montgomery countj'. This sandstone is found at a num- 
 ber of places along the Nishnabotany and its tributaries, in this coun- 
 ty. Thus far it has been also seen in the aoutheastern part of Pot- 
 tawattamie and the northeastern part of Mills counties. It seems to 
 lie in detached masses, or outliers, rather than as a continuous for- 
 mation, and the greatest thickness yet observed is thirty feet. Half 
 a mile belo\y Lewis, the county seat uf Cass county, it is quarried to 
 a considerable extent. The stone is soft when first taken from the 
 quarry, but hardens upon exposure to the atmosphere. It is of a 
 brown color, and in ordinary buildings presents a sombre appearance. 
 There are certain styles of architecture, however, in which this color 
 would not only be unobjectionable, but agreeable. 
 
 The upper coal - measure limestone is found along the creeks near 
 the border of Montgomery county, and also along the Nishnabotany 
 and its branches. The supply of limestone in the vicinity of Lewis 
 is abundant, and the quality good both for building and the manufac- 
 ture of lime. The western part of the county is quite well supplied 
 with timber, but there is a deficiency of fuel in the eastern part. 
 
 No coal has yet been found in this county, but it is not improbable 
 that the bed now worked near Quincy in Adams county, and also in 
 the northeastern corner of Montgomery county, may be found to 
 exist in this also. Should this be the case it will probably be found 
 no thicker, if so thick as it is there. 
 
 A.DAMS CODJN'TY. 
 
 Adams, like all other counties of the "Missouri slope," is a well- 
 drained, yet a well - watered county ; the drainage being effected prin- 
 cipally by the West and Middle Nodaways and their tributaries, 
 which also furnish excellent water for stock ; and in addition to this 
 the two rivers furnish a number of good mill privileges. Good wells 
 are obtained at a moderate depth in all parts of the county; it has 
 fully an average supply of timber, a considerable supply of stone, 
 and more coal which is now accessible than any other county to the 
 westward of or adjoining it. Its soil is also of the same excellent 
 quality which prevails in this part of the State. 
 
 If the county be divided through its center from north to south the 
 advantages of its resources are found to be singularly in favor of the 
 
REPORT OF STATE GEOLOGIST. 
 
 67 
 
 western half, for although the eastern half possesses an excellent soil, 
 a little timber — which is principally along the Nodaway — and good 
 water, yet the western half has, in addition to these, a very good 
 supply of timber, and all the coal and stone yet found in the county, 
 as well as all the valuable water power. The valleys of the Noda- 
 ways are narrower in this, than in the counties of Page, Taylor, and 
 Montgomery, but they are yet beautiful and fertile. The timber is 
 rapidly encroaching upon the prairies from the borders of the streams, 
 because the inhabitants keep the fires out in protection of their farms. 
 Stone, good enough for ordinary purposes, is found in every town- 
 ship of the western half, and coal is mined at intervals along the West 
 Nodaway from Harader's Mill, three miles north of Quincy, to about 
 the same distance below the town, on land owned by the Drs. Raw- 
 son of that place. 
 
 Near the middle at the crossing of the ri rer, two miles westward 
 from Qaincy, several openings have been made and considerable coal 
 taken out. Near this place Messrs. Barnett and Smith have sunk a 
 shaft to a depth of about forty - five feet below the bed of coal they 
 are now working with the hope of finding a still lower bed. They 
 have for the present discontinued their work upon it with the inten- 
 tion of resuming it. Such an enterprise is not unreasonable, 
 although undertaken without any previous experience in that direc- 
 tion in this part of the State, for the bed they are now working is the 
 same one which is worked in Taylor, Page and Montgomery coun- 
 ties, and the only bed yet discovered upon the "Missouri slope," 
 south of the north line of the third tier of counties. This bed of coal 
 also, as well as all the other strata which appear in Adams county, 
 belong higher in the series than the productive coal - beds along the 
 Des Moines river. As yet, however, we have had too little experi- 
 ence in our own coal - field to give positive encouragement to these 
 gentlemen to continue their work, although it would be perfectly in 
 accordance \iiih the principles of geology to do so, taking the hazard 
 of those beds having thinned out before reaching so far westward. 
 Should these lower beds exist there, it is not believed that they lie 
 at an impracticable depth, but this is a question which must be deci- 
 ded alter further investigation. 
 
 The people of this county give evidence of much thrift and public 
 
\ 
 
 gg EBPORT OF STATE GEOLOGISl. 
 
 spirit, and even the eastern half possesses many bright spots, made 
 so by the strong hand of honest toil, the society of which would shed 
 lustre and benefit on any part of the older States. 
 
 ADAIR COUNTY. 
 
 Adair County lies directly upon the dividing ridge between the 
 watersheds of the Mississippi and Missouri rivers. It is in this 
 county that Grand, and the East, and Middle Nodaway rivers have 
 their rise ; and North and Middle rivers are small prairie streams 
 where they enter its borders. The surface of the county is almost 
 entirely prairie, for its streams are all small, although called " rivers," 
 and as is usually the case with small streams in this part of the 
 State, very little timber is found along their borders. There is, 
 however, a sufficient supply of fuel of this kind for the present 
 inhabitants. 
 
 The drainage of the county is perfect, and yet there is no difiS- 
 culty in getting water for stock from the numerous streams, and for 
 domestic use, from wells and springs. The surface is more deeply 
 cut by the streams and their tributary branches and ravines than 
 one would expect to see in a regions lying upon a " divide," which 
 gives an unevenness of surface, which near the streams is too great 
 for convenient farming. 
 
 The soil however, is everywhere good, as in the neighboring 
 counties, and this broken region will afford excellent pasturage for 
 sheep, either with the wild, or cultivated grasses. 
 
 The only stone found in the country — except the drift boulders 
 — appear along Middle River, at frequent intervals from about three 
 miles south of the northern boundary, to where the river enters 
 Madison county, about the middle of the east line of Adair. At 
 various points near the river in township 76, range 30, almost any 
 desired quantity of limestone can be obtained, which for making 
 lime, and for the purposes of ordinary masonry, is very good. Near 
 the heads of Grand River a number of large boulders, quite large 
 for this latitude, are to be seen, the home of which, as almost every 
 one knows, is far to the northward. 
 
 On section 22, township 25, range 32, a dark carbonaceous matter 
 was found by the citizens exposed in a small branch of the Middle 
 
REPORT OF STATE GEOLOGIST. gg 
 
 Nodaway, and a shaft of a few feet in depth was sunk down to it 
 from the bank. 
 
 This, at the time of my visit, was partly filled with water, the 
 work having been discontinued. By bailing it out with a bucket, a 
 view of the bed was obtained and some specimens secured for further 
 examination. It has the appearance of impure coal, but lacks the 
 characteristic angular fracture of bituminous coal. No specimens 
 have yet been obtained beyond the action of the atmosphere and 
 frost, and when worked farther beneath the hill it may prove to be a 
 valuable article of fuel, particularly in a region where timber is so 
 scarce. 
 
 It is possible that this is the northern extension of the bed now 
 worked at Quincy and elsewhere. If so, it may prove more valuable 
 thitn present appearances would indicate, beside which, it is thicker 
 here than the Quincy bed has yet been found. 
 
 UNION COUNTY. 
 
 With the exception of half- a - dozen square miles of the extreme 
 northeast corner of Union, which are drained into Clanton's fork of 
 Middle river, the whole of Union county lies upon the Missouri 
 watershed, and is drained principally by Thompson's fork of Grand 
 river. Highland, near the center of the county, is the highest land 
 between the Mississippi and Missouri rivers on the line of the Bur- 
 lington and Missouri River Railroad, being twelve hundred and 
 eighty - seven feet above the level of the 'Gulf of Mexico, and eight 
 hundred and one feet above low water in the Mississippi river at 
 Burlington. The county is of the same size and shape as Adams, 
 which borders it on the west, and if divided through the center from 
 north to south the west half would be found in all respects similar 
 to the eastern half of that county in its prairie surface, being 
 sparsely supplied with timber, and also in containing no quarry rock. 
 The eastern half contains a considerable amount of timber along 
 Grand river and its tributaries, and from the vicinity of Afton to the 
 southeast cornsr of the county, good quarry rock may be readily 
 obtained at frequent intervals. This rock is of good quality for 
 building purposes, and the greater part of it will make excellent 
 lime, of which necessary material the inhabitants of some portions 
 
70 REPORT OP STATE GEOLOGIST. 
 
 of the neighboring counties obtain their supplies from this. The 
 soil of Union is excellent, and practically identical with that of all 
 those which adjoin it upon the southward and westward, being cov- 
 ered like those counties with a heavy deposit of drift material. 
 
 All the stratified rocks found in this county belong to the upper 
 series of coal - measure strata, so that there is little hope of finding 
 a workable bed of coal above the level of its deepest valleys, unless 
 the bed now being worked in Adams county shall be found to extend 
 into this. Even then it would probably be found to be very thin. 
 There is hope, however, that coal may yet be found at an available 
 depth beneath the surface. 
 
 It was observed that fruit - trees grow thriftily in this county, 
 wherever they have been planted, and Mr. John C. Wicks, who lives 
 a lew miles south - east from Afton, has succeeded admirably in cul- 
 tivating the principal fine varieties of grapes, of which he has a 
 flourishing little vineyard. 
 
 This, like the neighboring counties, beside being well watered by 
 its streams furnishes wells of pure, cold water, wherever the neces- 
 sities of the inhabitants require them to dig one. 
 
 The number of inhabitants is rapidly increasing by settlement, 
 attracted hither by the natural advantages which the county affords, 
 and also those in the immediate future to be derived from the early 
 completion of the Burlington and Missouri River Railroad, which is 
 to pass westward nearly through its centre, and will soon place its 
 inhabitants in direct communication with both the Atlantic and 
 Pacific sea - boards. 
 
 MADISON COUNTY. 
 
 The upper coal - measure series of strata are more fully developed 
 in this, than in any other county yet examined, and in the deep- 
 er valleys. The general dip of all the strata is found in the southern 
 part of the State, to be nearly or quite coincident with the fall of the 
 streams. But in the "Three - river country," as that region has been 
 called, which is drained by South, Middle and North rivers, the 
 drainage is to the eastward. Consequently in that portion of the 
 region toward the drainage of the Racoon fork of the Des Moines, 
 one would expect to find the lower series of coal - measure strata 
 
REPORT OF STATE GEOLOGIST. 'Jl 
 
 nearer the surface than they are farther to the southward. This is 
 actually the case, and although along Middle river from the middle 
 to the western part of the county, the upper series is in full force, 
 before reaching the north-eastern part of it, they have nearly or 
 quite disappeared, and the strata of the middle series only are seen. 
 These well - developed features of the geology of Madison county are 
 not only of great interest within its own borders, but the facility 
 afforded here for observing so complete a series, necessarily makes 
 the results of such observations the standard of comparison for sim- 
 ilar investigations over the whole region occupied by corresponding 
 strata 
 
 The subject of coal in this county has received as much attention 
 as it was possible to bestow upon it, the results of which have thus 
 far, been only partially satisfactory. From the mud - sill of Comp- 
 ton's mill on Middle river, one and a half miles southward from Win- 
 terset, to the level of the town plat, is about two hundred and thirty 
 feet in perpendicular height. The upper fifty feet of this is com- 
 posed of soil, sub - soil and drift material. The remainder, except 
 the stratum upon which the mud - sill of the mill, rests is at present 
 all referred to the upper coal - measures, the lowest stratum probably 
 belongs to the middle coal-measures, although at first supposed to 
 belong to the lower. 
 
 The following is a section of the rocks exposed in the valley of a 
 small creek a little southward from Winterset, numbered from the 
 top downward, omitting the fifty feet of drift which covers the whole 
 and which forms the surface deposit of the region around. 
 
 SECTION OF THE.KOCKS NEAR WINTEBSET. 
 
 No. 1. Thin bedded yellowish limestone 1 foot. 
 
 No. 2. Light-bluish marlite 4 " 
 
 No. 3. Gray, massive limestone -with dull fracture 6 " 
 
 No. 4. Gray, regularly bedded limestone with conchoidal fracture... . 13 " 
 
 No. 5. Black, laminated, carbonaceous shale 3 " 
 
 No. 6. Gray limestone with marly partings like No. 4 34 " 
 
 No. 7. Black shale like No. 5 2i " 
 
 No. 8. Regularly bedded gray limestone with many cherty layers... . 15 " 
 
 No. 9. Compact limestone with concretionary structure 3 " 
 
12 REPORT OF STATE GEOLOGIST. 
 
 No. 10. Limestone of varying quality — in some parts siliceous and 
 same of the interestitial material micaceous and finely 
 
 arenaceous l^i foot 
 
 No. 11. Impure coal i 
 
 No. 12. Light blue marlite 3 
 
 No. 13. Bluish, concretionary limestone, breaking readily into small 
 
 fragments • ^ 
 
 No. 14. Bluish and reddish clays 6 
 
 No.;l5. Sandy, micaceous shale, with fine grained micaceous sand- 
 stone in thin layers of bluish and greenish colors 71 
 
 No. 16. Bluish, shaly, impure limestone seen in the bed of the river at 
 
 Compton's mill 3 
 
 18H feet. 
 
 As one goes from the town to Compton's mill, on Middle river, 
 two miles southward from Winterset, he passes down through each 
 successive stratum, as it were, the small stream along which the road 
 runs having, in former ages, worn its valley through them, leaving 
 the edges of the firmer ones appearing at intervals in the sides of 
 the hills, while those of softer material are obscured by disinte- 
 gration. 
 
 By digging down beneath the stratum No. 16 at several places in 
 the vicinity, a very thin seam of coal was found. Thus it will be 
 seen that although two coal horizons exists in the series of rocks 
 exposed here, besides the two beds of carbonaceous shale, there is 
 little hope of finding a workable bed of coal near Winterset, above 
 the level of Middle river. 
 
 Going twelve miles northward from Winterset, in which direction 
 as before said the upper strata disappear, the bed numbered 16 is 
 found exposed in the right bank of the north fork of North river, 
 and thirteen feet of bluish shale underlaid by a bed of coal, all 
 appearing beneath it. 
 
 Working of the coal was suspended at the time the locality was 
 visited so that only one and a half feet of its thickness was seen. 
 Mr. George Clarke, the owner of the property, reports the coal to 
 be two and a half feet thick, which no reason was seen to doubt. 
 Some twelve miles southward from Winterset, at and near Ander- 
 son's mill, on Clanton's fork of Middle river, the same bed is 
 recognized, but it is there only eight or nine inches thick. 
 
KEPORT OP STATE GEOLOGIST. 73 
 
 These, so far as known, are the only exposures of coal yet found 
 in Madison county, but since the productive coal-measures lie beneath 
 all the strata found in this county, there is a reasonable hope that 
 an abundant supply may be obtained by sinking shafts. These 
 should of course be commenced in the valleys because 'they are 
 already cut out of the strata which must be bored through before 
 reaching the level of the streams if commenced on the high lands. 
 It is believed that coal would be reached within one or two hundred 
 feet from the valley bottoms, but no exact estimates can yet be given. 
 
 The beds No. 5 and No. 7 being a black carbonaceous shale are 
 often regarded by the people as an indication of coal, but although 
 they are often found associated with coal-beds, yet their presence is 
 of no value for such purposes. 
 
 At a number of places in the vicinity of Winterset, bed No. 3 of 
 the preceding section furnishes unusually fine, massive blocks of grey 
 limestone which are largely used in that region for building purposes, 
 and dressed blocks of it have also been carried as far as the capital 
 on common wagons. 
 
 The time will soon come when the counties which adjoin this upon 
 the south and west at least, will require facilities for obtaining the 
 stone which is so abundant along all the rivers of this county. The 
 other beds of limestone beneath the massive one just mentioned also 
 furnish immense quantities of stone for lime, and for ordinary mason- 
 ry, while there is enough broken stone in the beds of its streams 
 alone to McAdamize all its roads. 
 
 Timber of excllent growth and quality is also so abundant along 
 the streams as to make it desirable to check rather than encourage 
 its encroachment upon the prairies. These streams afford good 
 water, and upon the larger ones are numerous valuable water privi- 
 leges, many of which are improved by the erection of substantial 
 woolen, flouring and saw mills. 
 
 The quality of the soil is not surpassed anywhere, and the general 
 aspect of the county is one of unusual beauty. The monotony which 
 often accompanies prairie views is here completely relieved by gentle 
 undulations, and the wooded hillsides and valleys. 
 10 
 
74. REPORT OF STATE GEOLOGIST. 
 
 SALT, 
 
 The following article was written and published in the newspapers 
 as a reply to numerous enquiries by letter from different parts of the 
 State as to the prospect of finding salt in Iowa in paying quantities, 
 particularly in Davis county, where " saline lands " have long been 
 understood to exist: 
 
 By the word salt, we invariably mean in common language, what 
 the chemist invariably means by " chloride of sodium," and no one 
 misunderstands us. But he uses the same word in a far more exten- 
 ded sense than we, and makes it signify any substance which results 
 from the chemical union of any acid with any base. Consequently 
 be has almost an infinite number of different salts, some of which 
 readily dissolve in water, but many others are as insoluble as the 
 rocks themselves ; and a part of these are indeed nothing more or 
 less than chemical salts. Thus nature also produces, in her chemical 
 laboratory, both soluble and insoluble salts ; that is, soluble or insol- 
 uble in water. , The most abundant of the latter is limestone ; of the 
 former, salt. Further on, water saturating the earth under certain 
 circumstances will be mentioned. This, all will understand. We 
 shall also speak of water being saturated with salt. This is the 
 chemists' use of the word, and signifies in this instance, water having 
 dissolved all the salt of which it is capable, when any more being 
 added would fall to the bottom and remain there undissolved. When 
 water is fully saturated, it contains about 36 per cent, of salt, 
 whether hot or cold. 
 
 In writing upon subjects related to chemistry, one is often obliged 
 to make use of some of its technicalities ; hence these few words of 
 explanation. The sea, as every one knows, is the great repository 
 of common salt, but perhaps every one does not know, which is 
 really the case, that sea water also holds in solution many other 
 salts besides this, but in very much smaller proportion. These are 
 almost the sole cause of the impurity of all salt artificially manu- 
 factured from sea water. When good salt is produced from sea 
 water, as is now the case on Turk's Island and many other parts of 
 the world, it is by a natural purifying process of crystalization, 
 resulting from the slow evaporation of the water by the heat of 
 
REPORT OP STATE GEOLOGIST. 75 
 
 the sun, which affords time for the chemical separation of the 
 other salts, -which is only partially accomplished by the artificial 
 process. All the salt obtained as such, from the mines of different 
 parts of the world, are believed to have been originally produced 
 from sea water by a natural process, similar to the one referred to, 
 at a time when the place which the deposit now occupies, formed 
 a broad shallow lagoon near the shore of a then existing sea, and 
 with which it communicated at full tide. As the sea receded, by 
 the ebb of the tide, evaporation of the shallow water of the 
 lagoon continued without interruption, leaving behind a greater 
 amount of salt than served to saturate it. This excess of salt 
 constantly increased, because nothing but pure water passed . off 
 as a vapor, and because every returning flood of the tide brought 
 more salt as well as more water, until the lagoon was filled with salt, 
 and would receive no more water from the sea. This process may 
 now be observed in several parts of the world, and should some 
 geological change of the earth's surface take place, as they have 
 taken place in past ages, to bury these salt deposits beneath the 
 earth, the salt there would be in the same condition as that of the 
 mines of England, Poland, and other parts of the world. Thus we 
 see that the salt of mines, although deep within the bowels of the 
 earth, has doubtless been derived from the sea, or from an inland 
 salt lake where it has accumulated by a process presently to be 
 described. But notwithstanding this fact, the original home of the 
 salt is in the earth, and not in the sea, for it is believed that all 
 the water upon the earth once existed in the form of vapor diffused 
 in the atmosphere surrounding a red-hot world, and vapor can 
 contain no common salt. 
 
 After the surface had cooled sufiiciently to form a crust, the vapor 
 began to condense ; and these first rains were as fresh, so' far as 
 containing common salt is concerned, as those which fall upon our 
 heads to - day. The first seas were formed by the rains, in the 
 depressions which they found upon the surface, and their waters 
 were comparatively fresh, for nearly all the soluble salts, (of which 
 salt is the chief,) or their chemical constituents, were yet dissem- 
 inated in the substance of the earth. A still further cooling of the 
 earth's crust, and disintegration of its substance, admitted free 
 
76 REPORT OF STATE GEOLOGIST. 
 
 percolation of the water -which fell upon its surface and which in 
 its passage again to the sea, took up the soluble salts with which it 
 came in contact in its terrestrial passage, in addition to those which 
 may have existed in the bed upon which the sea was formed. Thus 
 the sea has derived all its salt from the earth by a process of leach- 
 ing similar to that by which the frugal housewife obtains potash -lye 
 in the domestic manufacture of soap. Thus its waters have constantly 
 increased in saltness from the earliest to the present time ; for the 
 rivers of the world are even now carrying down salt to the sea, 
 although the amount of their water is proportionally so great that 
 it is perceptible only by the most careful analysis. The immense 
 amount of fresh water constantly poured into the sea does not 
 diminish its saltness by dilution, but on the contrary, constantly 
 increases it by addition of salt, while the same amount of water 
 which the rivers bring, is returned to the earth again by evaporation. 
 Whenever the relative positions of sea and land have been 
 changed, and such changes have been many in past geological ages, 
 every lake which may have resulted from the elevation of land from 
 the bottom of the sea, was as salt when it was first formed, as the 
 sea from which it derived its waters ; but when such a lake had an 
 outlet, the accumulation of waters beyond and around its surface by 
 drainage, soon rendered it as fresh as the streams which emptied 
 into it. But where such a lake or inland sea has no outlet, the sur- 
 face would rise or fall to a level at which the evaporation just 
 equalled the supply of water, which level would have no necesary 
 relation to that of the great sea, which is also determined by the 
 same law. Such a lake would increase in saltness from the same 
 cause that the sea has done, but more rapidly if the area drained 
 into it contained more than the average amount of soluble salts. 
 When -the salt in the water of such a lake had increased to the 
 degree of saturation, it would commence to be precipitated, and form 
 upon the bottom, a bed of crystalline salt. This is actually the case 
 in Great Salt Lake, as well as in others. But still other salt lakes and 
 inland seas have not yet reached this point of saturation, and they 
 consequently precipitate no more salt than the great sea does. 
 Should Great Salt Lake is future geological times become buried 
 under other strata of the earth, its bed would be a subterranean 
 
REPORT OP STATE GEOLOGIST. 7 7 
 
 deposit of salt, similar to some that are now known, which, doubtless, 
 had a similar origin, if they did not originate in lagoons as before 
 described. The salt of such a deposit might never have had, either 
 directly or indirectly, any connection with the sea, any more than 
 the salt of Great Salt Lake has had. 
 
 Although the earth, and not the sea is the original home of the 
 salt, yet in the various elevations of the land above the sea, composed 
 of strata which were formed there, or of the muddy sediment of 
 marshes which existed upon its borders, it was impossible that they 
 should not have retained within their substance some of the salt of 
 the water with which they have been constantly saturated, and in 
 this sense some of the salt disseminated throughout the substance of 
 the earth, may be said to have been derived from the sea. Now 
 when these strata, which are always more impervious to water ver- 
 tically, than horizontally, were elevated, they were almost never left 
 in the horizontal position in which they were deposited, but in the 
 movement of elevation were more or less tilted, so that drainage by 
 percolation could take place throughout the mass in the direction of 
 the interstices between the layers, and the greater part of the salt 
 they may have contained was thus really carried back to the sea 
 again. But suppose a series of such strata, composed, as is usually 
 the case, of material, alternating, more and less impervious to water, 
 to have been elevated in such a manner that their dip around the 
 whole area which they occupied should be toward the center, and 
 they resting upon each other like a pile of saucers in the dish - pan 
 of the housewife with the water between them. In such a case all 
 the saline substances they may have contained at the time of their 
 elevation would remain there just as the water would remain in the 
 saucers if carefully lifted from the pan. Water would indeed pen- 
 etrate the mass by percolation from the surface but find no channel 
 out, would escape only by the ordinary process of evaporation from 
 the same surface, leaving all the saline matter behind. Consequently 
 upon boring down through the mass, water would be obtained in 
 those strata which are most permeable by it, and this would be found 
 to be salt water. Such a condition of strata actually exists, occu- 
 pying nearly the whole southern peninsula of Michigan, as was first 
 pointed out by Prof. Alexander Winchell, the State Geologibt, to the 
 
'j£, REPORT OF STATE GEOLOGIST. 
 
 correctness of whose predictions in relation to the abundance of salt 
 his State would soon produce, every market in the country now gives 
 ample testimony. ^ 
 
 The salt of the Michigan brine may never have existed in the 
 crystalline form since it was first leached into the sea from the place 
 of its original distribution, but brine is sometimes obtained from the 
 earth which hay probably derived its salt from such deposits as have 
 just been referred to, in its passage through them beneath the earth. 
 Such deposits are sometimes found containing so much earthy 
 admixture that to obtain the s It in an available form, fresh water is 
 artificially added to produce a brine, from which it is then manufact- 
 ured in the usual manner. Thus we see that the present distribu- 
 tion of salt in the earth has originated from a variety of causes. It, 
 or its component elements were originally disseminated throughout 
 the substance of the earth, the greater part of which has been 
 carried to the sea by a leaching process of nature ; that the stratified 
 rocks have salt also disseminated through them as a result of satura- 
 tion by the sea water in which they were deposited ; that it exists 
 also in the earth as an accumulation of brine ; as subterranean 
 deposits of crj^stalline salt derived from ancient lakes, lagoons and 
 marshes, and finally as brine formed from such deposits by the 
 percolation of fresh water through them. It is only by the three 
 latter methods that a sufficient accumulation has taken place in the 
 earth to render its production possible in such quantities as our 
 necessities require. 
 
 The question then very naturally arises : have we in Iowa any 
 evidence of the existence of deposits of salt, or of a condition of 
 the strata which would retain the brine of the sea in which they 
 were deposited? As regards deposits of salt beneath the surface of 
 our State, while we have yet no evidence that any such exist in the 
 crystalline form, we certainly have none that they may not yet be 
 discovered. There are springs in different parts of the State, the 
 waters of ^\hich contain small quantities of salt, but so far as I am 
 yet aware, these are all confined to those regions underlaid by coal- 
 measure strata. It is possible that this salt is derived from 
 crystalline deposits of that material, but we have yet no evidence of 
 the existence of them. If the coal with some of its associated strata 
 
REPORT OF STATE GEOLOGIST. 79 
 
 were formed in broad marshes in close connection with the sea level, 
 as is generally believed, then we may infer that the salt of the coal- 
 measure strata of Davis county was derived from that which was 
 then freely distributed throughout those marshes. Whatever may 
 have been its origin, the reason that it remains in those strata may 
 be due to the fact that while the general dip of all the strata of the 
 State is to the southward ; there is also a slight counter dip to the 
 westward in the southeastern part, forming at least two sides of a 
 very shallow depression in the strata (not in the surface), which may 
 have served to collect the saline matters ot the strata there into that 
 region, of wnicli the northeastern part of Davis county may proba- 
 bly be a centre. Some of these waters have been analyzed, and 
 proving to contain less than one per cent of salt the prospect of 
 obtaining it in paying quantities is not now encouraging. Yet, as 
 before intimated, there are no positive reasons why it may not exist 
 in such quantities in our State. 
 
SECOND ANNUAL REPORT 
 
 OP 
 
 CHAELES A. WHITE, M. D., STATE GEOLOGIST. 
 
 To Bis BxceUency, William M. BtoTie, Governor of Iowa : 
 
 Sir : I herewith transmit to you my second annual report of progress of th-e 
 State Geological Survey, together with copies of reports of Mr. O. H. St. John, 
 Assistant, and Prof. Gustavus Hinrich, Chemist. 
 
 I also herewith transmit, as a part of my report, copies of fourteen letters in 
 relation to the geological work, which I have prepared and published from time 
 to time in the newspapers of the State, in accordance with the provisions of law. 
 Accompanying these are also copies of a number of letters prepared and similarly 
 published by Professor Hinrichs and Mr. St. John. 
 
 Immediately after my first annual report of progress to you, I commenced the 
 arrangement and study of the collections made during the previous season, and 
 also the preparation of papers upon subjects connected with the State Geologica 
 Survey, for publication in the scientific journals. These were duly credited to the 
 survey in tlie imprint of their titles, so that the State should receive credit for 
 the priority of investigation and discovery, which would otherwise be in danger 
 of loss by delay of their publication in our final report. 
 
 On the 15th of March I was joined and assisted in these labors by Mr. St. John, 
 whom I had previously appointed Assistant. 
 
 The opening of spring being later than usual, no field - work was^done until the 
 16th of April. Intending to devote the greater part of the year's labor to the 
 investigation of our resources for fuel, this work was commenced on that day in 
 Mahaska county, and continued until the 6th of May, embracing the examination 
 of the coal deposits of the greater part of the counties of Mahaska, Monroe, Jef- 
 ferson and part of Wapello. 
 
 It being then necessary to commence field - work in the western part of the 
 State where it was left at the close of the previous season, preparation was made 
 to proceed thither with the appropriate outfit. At this time I received a proposi- 
 tion from the eminent naturalists, Mr. F. B. Meek and Dr. Theodore Gill, both of 
 the Smithsonian Institution, and both also connected with the United States Geo- 
 logical Survey of Nebraska, to accompany me across our State to Nebraska, 
 review on the way a part of my last season's field-work, and meet Dr. F. V. 
 Hayden, Director of the Nebraska Survey, at Nebraska City, to compare notes, 
 11 
 
82 REPORT OF STATE GEOLOGIST. 
 
 and if possible, to arrive at some estimate of the depth at which the equivalents of 
 the productive coal - measures lie beneath the unproductive strata exposed along 
 the Missouri river. This proposition was very gladly accepted, especially since 
 the first - named gentleman is probably better acquainted with the geology of the 
 Missouri river region than any other person living. 
 
 Accordingly upon the arrival of Mr. Meek and Dr. Gill we all started in com- 
 pany from Iowa City on the 32d of May, and arrived in Nebraska City on the 6th 
 of June, where we were joined by Dr. Hayden. We made some satisfactory esti- 
 mates of the aggregate thickness of the strata exposed within the limits of Iowa, 
 but judging from exposures found by those gentlemen in Nebraska and Missouri, 
 it seems probable that there is a thickening of the strata to the westward, which 
 the Iowa exposures do not reveal, so that the equivalents of the productive coal 
 strata which are seen along the Des Moines river, lie deeper beneath the surface 
 along the Missouri river than^would have been inferred by an examination of 
 Iowa rocks alone. 
 
 Circumstances obliged me to suspend the investigation of this important sub- 
 ject, but I still think it reasonable to expect to find coal there at less depth than 
 that at which it is successfully mined in some other parts of the world. 
 
 Parting with our distinguished friends at Council Bluffs, I placed Mr. St. John 
 in charge' of the work in the western part of the State, assigning to him for 
 examination that portion of the fourth, fifth and sixth tiers of counties which lies 
 between the Missouri and Des Moines Rivers. He has prosecuted his labors 
 with an earnestness and zeal which can only be inspired by a love of science ; 
 and I am much gratified with the careful and able manner in which he has per- 
 formed the work assigned him. I respectfully refer you to his report of progress 
 to me, a copy of which is herewith submitted. 
 
 Returing to Iowa City, I accompanied Prof. Hinrichs to the lead - mines of 
 Dubuque, for the purpose of obtaining material and information in regard to the 
 mode of occurrence of those ores, and the methods in use for smelting them. 
 Although our stay there was brief, the results obtained were of much interest 
 and value. 
 
 Resuming the fuel investigations, I visited all the operated mines in the counties 
 of Marion, Wapello, and Van Buren, entering and examining them in person, and 
 collecting authentic specimens for analysis. 
 
 The dryer part of the year having arrived, I made the necessary preparation, 
 and in the latter part of August went to the northern part of the State to examine 
 the country for peat, directing attention principally to the counties of Franklin, 
 Wright, Cerro Gordo, Hancock, Worth, Winnebago and Kossuth. Very large 
 quantities of this valuable fuel exist in those counties, as will be seen by refer- 
 .ence to the accompanying letters. 
 
 Those examinations were continued until the commencing cold weather made 
 it hazardous to health, when, returning by way of Ft. Dodge, I met Mr. St. John 
 there with his camp, and together we spent the greater part of two weeks in the 
 examination and mapping of the large gypsum deposits of that region. 
 
 Pleasant weather continuing later than usual in the autumn, both Mr. St. John 
 
REPORT OP STATE GEOLOGIST. gg 
 
 and myself made frequent excursions to such points as it seemed most desirable 
 to examine. Among these excursions were visits to important peat marshes in the 
 counties of Muscatine, Linn and Clinton. 
 
 The usual winter work is now in progress, the results of which promise to be 
 of increasing^interest and importance. 
 
 I beg to call your especial attention to that portion of the report of the chemist 
 in which he describes his methods in the cheminal analysis of coals, which he 
 claims to be new and eminently practical. 
 
 It will be seen that thus far the work of the survey has been one of general 
 reconnoissance rather than of detailed field - investigation, and much of such 
 general work yet remains to be done. It is necessary to ascertain the geological 
 structure of the northwestern portion of the State, and to make further general 
 examinations in the coal and peat regions. After this the details of our .geology 
 should be fiilly investigated ; especially should we know with the greatest pos- 
 sible accuracy the minute geological structure of our coal - field, for upon this 
 knowledge depends the intelligent prosecution of mining operations, and the 
 consequent avoidance of useless expenditures of money and labor which will 
 otherwise be sure to occur. 
 
 Application will be made to the Twelfth General Assembly for a suflBcient 
 appropriation to prosecute the work to a successiul completion. The people 
 everywhere evince a lively interest in the success of the survey, and their uni- 
 form kindness to its oflBcers is a constant source of gratification. 
 Very respectfully, your obedient servant, 
 
 CHARLES A. WHITE, 
 
 State Qeologut. 
 Iowa City, Iowa, -January 3, 1868. 
 
REPORT 
 
 0. H. ST. JOHN, ASSISTANT STATE GEOLOGIST. 
 
 To Dr. C. a. White, State Geologist: 
 
 Dbak 8ik: In accordance ■with your instructions, I have prepared and here- 
 with submit the following report of progress of the field - investigations under my 
 charge during the pnst season. 
 
 In compliance with your instruclions, on the 13th of June last I began the pre- 
 liminary survey of that portion of the State comprising the fourth, fifth and, in 
 part, the sixth tier of counties lying between the Des Moines and Missouri rivers. 
 One of the principal objects of this reconnoissance was to ascertain with as much 
 accuracy as possible in so short time, the extent and character of the coal-field 
 in the region embraced in this geological district. With this view, I made a jour- 
 ney from Council Bluffs up the valley of the Missouri, through Harrison, Monona 
 and Woodbury counties to Sioux Gity ; thence we passed into Crawford, Shelby, 
 Audubon, Carroll and the southern portion of Sac county. The above enumerated 
 counties, with the exception of the eastern porlion of Carroll and Sac counties, lie 
 wholly upon the Missouri water - shed, and present a variety of physical features 
 which one would hardly suspect from a casual glance. 
 
 Few rock exposures occur in the above-named counties; however, there are 
 localities which supply a very fair quality of stone for all the ordinary porposes 
 of construction. It is believed, further, that the manufacture of bricks for build- 
 ing may be successfully undertaken in almost all localities; so that, after all, the 
 scarcity of good building - stone in most places will scarcely be noticed, much less 
 can it ever have a detrimental influence in a region so highly favored in other 
 respects. 
 
 In the region about Sioux City good quarry rock is obtained from the lower 
 members of the cretaceous deposits there exposed; and a fair quality of quick- 
 lime is manufactured from the upper chalky beds known among geologists as the 
 iTWceramus ieds, from the prevalence of this shell in this horizon. In the imme- 
 diate neighborhood of Sioux City, at Sargent's Bluffs, and at Bruguier's Bluffs, 
 and above on the Big Sioux River, the lower members of the cretaceous are 
 beautifully exposed, enabling us to construct a complete section of these rocks of 
 above one hundred and thirty feet in vertical thickness, and which were studied 
 in as much detail as the limited time at my disposal would permit. On the 
 Boyer, in Harrison county, limited exposures of strata belonging to the upper 
 
REPORT OF STATE GEOLOGIST. 85 
 
 coal - measures also outcrop, and are quarried to some extent in the vicinity of 
 Reel's mills, on the line of llie Ciiicago & Norttiwestern Railway. At other 
 points in Harrison and Monona couniies, a tufaceous deposit occurring near the 
 base of the "bluff formation," affords a. durable material for underpinning, &c. 
 41s3 in other parts of these counties the modified drift affords limited exposures 
 of a more or less coarse ferruginous conglomerate, and considerable quantities 
 of lower Silurian limestone boulders, gneissoid and quartzose boulders are met 
 with, particularly upon the broad upland ridges in Jda, Crawford, Carroll and 
 Sac counties. 
 
 What most strikes the observer, traveling over these prairies, is the unusual 
 development of the post - tertiary deposits, affording him one of the most inter- 
 esting fields of research. An extensive and intimate knowledge of these laler 
 geological deposits —comprising the glacial drift, the sands and coarser materials 
 of the modified drift, the fine class ot the bluff and finally the thick accumula- 
 tion of soil at the surface — would have the most direct and practical bearing 
 upon the development of the agricultural resources not only of this particular 
 section, but of the State generally. Throughout this region the soil is unsurpassed 
 in fertility, and the very numerous water- course affords a perfect system of drain- 
 age, thus furnishing a satisfactory explanalion for the remarkable infrequency or 
 wet, untillable land. 
 
 The heavy deposits of drift, &c., which so extensively prevail and to a great 
 extent conceal from view the underlying rock formations in the counties men- 
 tioned in brief above, offered insurmountable obstacles to the snccessfal examin- 
 ation of the carboniferous strata which arc supposed to underlie a large portion 
 of that section of the country. Therefore it became a matter of greatest impor- 
 tance to explore the country lying to the eastward, or between the grand divide 
 and the Des Moines river, that the necessary d.vta might be sought by means of 
 which to enable us to arrive at some satisfactory conclusion regarding the nature 
 of the strata in the region to the westward. Commencing these explorations in 
 Green county, I first made a tolerably detailed examination of the valley of the 
 North Coon, and subsequently its two principal tributaries, the South and Middle 
 Coon rivers, and .their numerous affluents in Guthrie, Dallas and Polk counties, 
 The first exposure ol unequivocal coal -measure strata is found in the south- 
 eastern part of Green county; and thence along the North Coon to the confluence 
 of the South Coon, the bluffs which continuously border either margin of the 
 valley, afford quite extensive and very satisfactory exposures of the coal-meas- 
 ures, consisting of sandstones, arenaceous and argillaceous shales, occasional 
 layers of limestone, and two or three thin beds of coal, which latter are being 
 worked at numerous points in the valley. 
 
 The South and Middle Coon valleys also contributed valuable data. In the 
 region bordering upon the lower reaches of these streams, we recognized a set of 
 beds which attain a thickness of about two hundred feet, and which hold a position 
 intermediate between the coal -bearing strata, of the Des Moines river region 
 and the upper coal - measures, which latter series you saw admirably defined 
 during your investigations the first year of the survey in Madison county and 
 
gg REPORT OF STATE GEOLOGIST. 
 
 the southeastern portion of the State. This middle series of strata is composed 
 of thin beds of sandstone, sandy shales and variegated clays, impure limestones 
 always in comparatively thin bands, and sometimes wanting wholly, carbon- 
 aceous shales and coal. There are .three distinct and constant coal horizons, 
 which separate or sub - divide the liees into as many lithologically well - marked 
 groups. But the palaeontologioal characters bind the whole together, as it was, 
 and indicate a nearer alliance to the lower coal - measures — as we at present under- 
 stand that series — than they do to the upper measures, from which latter it is quite 
 distinct in its llthological features also. The three beds of coal above mentioned 
 are mined with considerable success at the present time in both Guthrie and 
 Dallas counties, and the quality of the coal is usually excellent, although 
 the beds are very thin, possessing an aggregate thickness not above four feet. 
 The productive or lower coal - measures lie beneath at variable depths, and can 
 be reached, doubtless, by ordinary shafting at most any point in these counties at 
 a depih of two hundred to three hundred feet, and in valleys at a much less 
 distance below the surface. Indeed, at Redfield, in Dallas county, where a bed 
 of coal nearly three feet thick, which outcrops in the banks of the Middle Coon, 
 and is overlaid by a thickness of at least forty - five feet of sandstone, and which. 
 It is believed, is equivalent to the coal seen at Des Moines. This bed has, there- 
 fore, been upraised so as to occupy about the same elevation above the level of 
 the Middle Coon at Redfield as it does above the level of the Des Moines river at 
 the Capital. And the intervening country forms a broad, shallow synclinal, the 
 axis of which has apparently a nortjierly and southerly direction. Hence it is 
 that at the South and North Coon rivers, there occur beds which belong pretty 
 well up in the middle series, or to its middle groups of strata. 
 
 As we ascend all three of the Coon rivers, to the northward, we encounter 
 sandstones and clays, and ferruginous grits, in Guthrie, Carroll and Greene 
 counties, the equivalency of which have as yet not been satisfactorily determined. 
 And in carrying on these examinations up the beautiful little valleys of the 
 tributaries of the South Coon, in the southern portion of Guthrie county, the 
 westward dip of the strata has bronght down the lower members of the upper 
 coal - measures almost on a level with the valley of Deer creek ; but before we 
 have gained the headwaters of Beaver creek, whose course is nearly parallel with, 
 and only two or three miles north of the former stream, the strata have again been 
 upraised, so that in the vicinity of Mr. Mann's and Mr. Cleman's, in Townships 
 78 and 79, RMnge 31, W., we are again brought in contact with familiar horizons, 
 long since recognized. at Vanmeter's, a few miles above the mouth of South Coon, 
 and alsonearAdel, on the North Coon, &c. We need no more conclusive evidence 
 to prove the irregularly and gently - undulating character of the strata in this 
 section. The most easterly indication of one of these broadly swelling - anticinals, 
 in connection with the middle series of coal-measures, is seen in the bluffs which 
 border the north side of the Coon river, a few miles above Des Sloines, and in the 
 region to the southward, in Warren county. Beyond this line of outcrop — east- 
 ward — not a vestige of the middle series has thus far been detected. 
 
 The importance, I may say the necessity, of a thorough and well- sustained 
 
REPORT OF STATE GEOLOGIST. 87 
 
 exploration of the area occupied by this most important mineral product within 
 our borders, must be apparent to every intelligent person; for, I believe, we shall 
 be able, when once the details of the structure of our coal- measures shall have 
 been fully worked out, as has been done in other states, to estimate the depth at 
 which a certain bed of coal may be found at any given point, with almost as great 
 accuracy as we measure up the bared face of a river bluff in order to ascertain 
 the thickness of the strata therein exposed. However, much still remains to be 
 accomplished in this section of the State, before the work shall have attained that 
 degree of perfection which shall contribute largely to the economic interests of 
 the State, and merit the commendation of the public. 
 
 During the summer my friend Mr. J. A. Allen, of the Musuem of (Comparative 
 Zoology, Cambridge, joined my party, with the view of studying the Natural 
 History, particularly the Ornithology and Botany of the State ; and to this end 
 he made valuable collections of objects of natural history, and I doubt not he will 
 cheerfully, at the proper time, prepare his observations in a form which shall 
 receive the highest approbation of our people. 
 
 It would be superfluous to extol the merits of a region so well and favorably 
 known already, as that comprising the four or five eastern counties of the district 
 herein mentioned. And it is with grateful acknowledgements I return my sincere 
 thanks for the many courtesies my party received at the hands of gentlemen in all 
 parts of the District. 
 
 On the 8th of October, in compliance with your request, I discontinued the work 
 in the counties west of the Des Moines, and joined you on the 10th, at Fort 
 Dodge. 
 
 Very sincerely and respectfully. 
 
 Tour obedient servant. 
 
 ORESTES H. St. JOHN. 
 
 Iowa Citt, 38th Dec, 1867. 
 
POPULAE LETTERS 
 
 THE STATE GEOLOGIST 
 
 B^ O R 18 6 7. 
 
 12 
 
SURVEY OF COUNTIES. 
 
 MAHASKA COUNTY. 
 
 The principal object aimed at in these partial examinations of 
 Mahaska, Marion, Monroe, Wapello, Jefferson and Van Buren coun- 
 ties, was to place before the public reliable information in relation 
 to the mineral resources of those regions, that those who were con- 
 templating the investment of capital in public improvements, manu- 
 factories, or other enterprises, might know the advantages our State 
 affords. 
 
 The largest part of the labor performed was in the examination 
 of the mines and outcrops of coal. The mines were all entered and 
 examined in person, specimens from different parts of the bed col- 
 lected for analysis, and notes taken of its thickness and general 
 character. 
 
 The St. Louis limestone (sub - carboniferous) is found cropping out 
 near the bottoms of the valleys of the Des Moines and Skunk 
 rivers, as well as some of their tributaries. Thus it is known that 
 all the coal of the county, which is immense in quantity, will be 
 found in the high lands above the level, at least of the Des Moines 
 river, because it is useless to search for coal beneath the limestone 
 of this region ; so that no very deep mining will be necessary to 
 reach all the coal that the county contains. That which is now 
 mined is reached by drifting into the sides of the valleys of the 
 rivers, creeks and ravines. 
 
 In the north part of the county, near the confluence of Buck 
 creek with the north branch of Skunk river, several mines have been 
 opened in a four - foot bed of coal, and many more may without 
 doubt be opened there whenever the demand will warrant it. Along 
 Spring creek, from near its confluence with South Skunk river to 
 
92 REPORT OF STATE GEOLOGIST. 
 
 within a mile or two of Oskaloosa, several mines have been opened, 
 the coal of which ranges from four to upward of five feet in thick- 
 ness. On this creek there is reason to believe that two good beds 
 of coal exist, the one beneath the other. There is no doubt that 
 large quantities of coal exist along this creek, which may be readily 
 mined by drifting into the beds at their out - crop or approach to the 
 surface on each side of the valley. 
 
 Around the outskirts of Oskaloosa several mines were visited the 
 beds of which varied from three and a half to five and a half feet in 
 thickness, and there is no doubt that the whole city is underlaid by 
 a good bed of coal at a moderate depth. At Oskaloosa Station, on 
 the D. V. Railroad, two and a half miles from the city, the thickest 
 bed of coal is worked yet known in the State. It measures from 
 five to nearly eight feet thick of solid and good coal. Messrs. 
 Roberts & Co., and the Iowa Coal Company of Keokuk, both have 
 mines in operation in this bed near the station, and the coal in their 
 mines will probably average six feet in thickness, and in several 
 places it reaches seven and a half feet thick. They are conveniently 
 ocated in relation to the railroad, having car - tracks laid from the 
 railroad platform all the way into the rooms whore the mines are 
 working. The coal cars are drawn all the way into the mines by mules 
 of ordinary size without difficulty. Two thousand five hundred 
 bushels daily are shipped from these two mines, beside a consider- 
 able quantity of coke, of good quality, which they have lately 
 commenced preparing for shipment. 
 
 Several other openings have been made within a few miles of 
 these, and the coal found to be as thick as in the two mines just 
 mentioned. All along the line of the Des Moines Valley Railroad, 
 and of the proposed Iowa Central Railroad, between Oskaloosa and 
 Eddyville, there is an abundance of coal which may be readily made 
 accessible for shipment upon those roads, both near their main tracks, 
 and by running branch tracks up the branches of Muchekinock creek, 
 and opening mines on each side of them by drifting into the hill -sides. 
 
 There is no reasonable doubt that the whole ridge between the 
 creek before named and the Des Moines river is underlaid by at 
 least one good bed of coal, and indeed it is quite as conclusive that 
 the higher lands of the greater part of the county are so underlaid. 
 
REPORT OF STATE GEOLOGIST. 93 
 
 The St. Louis limestone furnishes a good supply of building - rock 
 and lime, the brick -clays are of average quality and timber is more 
 plentiful than is usual in Iowa. 
 
 MONROE COUNTY. 
 
 Along all the creeks and streams of Monroe county, coal is to be 
 found, but the lower and better bed is reached only in the deeper 
 creek valleys, because the county, lying upon the divide between the 
 drainage of the Mississippi and Missouri rivers, is rather higher than 
 those adjoining it, and the material above the coal is consequently 
 thicker. It is probable that large quantities of coal may be obtained 
 by sinking shafts down from the high lands to a depth not exceeding 
 two hundred feet. Along Miller's creek on the line of the Iowa 
 Central Railroad there have been a number of mines opened, and 
 much coal may doubtless be obtained there by the usual process of 
 mining. On Bluff creek, from four to six miles northward from 
 Albia, several mines are opened, and many more may be. On Cedar 
 creek, in the northwestern part of the county there is a bed of coal 
 exposed in the bed of the creek which has been found to be nearly 
 seven feet thick at that point. 
 
 On Coal creek, three miles westward from Albia, a bed of coal 
 only thirty inches thick but of excellent quality is worked. At this 
 min&, upon the clay floor of an abandoned opening a quantity of an 
 efflorescent astringent substance was found which the chemist reports 
 to be native alum. Standing in little pools around the mouth of 
 the mine, and more particularly near a mine on Bluif Creek in the 
 north part of the county, a deep - red colored water is found. This 
 the chemist reports to be a solution of the per - sulphate of iron, 
 with sulphuric acid in excess, as well as a little free phosphoric acid. 
 On the line of the Burlington and Missouri River Railroad, near 
 Chillicothe, along Avery's creek in the east part of the county, Mil- 
 ler's creek in the northeastern part, and along Cedar creek in the 
 north western part, this lower and thicker bed of coal has been 
 worked, affording an abundance of good coal. The upper and 
 thinner bed, from two three feet in thickness is opened at numerous 
 localities along the valleys of the smaller streams in varous parts of 
 the county, particularly in the vicinity of Albia. The quality of 
 
94 REPORT OF STATE GEOLOGIST. 
 
 this upper bed of coal is equal to that of the lower bed, which is 
 worked in the creek valleys before referred to. The sub - carbon- 
 iferous limestone is found near the mouth of Miller's creek, at which 
 point alone it has been seen within the county, the other streams, so 
 far as known, not having cut their valleys down so deeply as to 
 expose it. 
 
 Along many of the creeks of this county there are exposures of 
 sandstone which furnish a very good material for common masonry, 
 it being harder and firmer than the coal - measure sandstone usually 
 
 IS. 
 
 The limestone referred to, without doubt extends beneath the 
 whole county, forming the floor of the coal - measures, and if this 
 limestone is reached in boring or digging for coal, the work should 
 be stopped, for there is no hope of finding coal beneath it. 
 
 Timber is sufficiently abundant in Monroe county to furnish fuel 
 for its inhabitants, even if they had no coal, and the abundance of 
 the latter fuel will always keep the former at a reasonable price for 
 those who prefer to use it." 
 
 JEFFERSON COUNTY. 
 
 Jefferson county has been known longer perhaps tha"n any other 
 county in the State as a coal region, and many years before any 
 railroad had reached Iowa, Fairfield coal was carried in wagons to 
 the Mississippi river towns, and was in high repute among black- 
 smiths. 
 
 The Burlington & Missouri River Railroad has since been built 
 near these mines, which are now worked by two parties, Mr. Heron 
 and Mr. Richardson, who ship the greater part of their coal to Bur- 
 lington. 
 
 At Coalport, ten miles eastward from Fairfield and on the line of 
 the same railroad, a four- foot bed of coal is -yorked by Messrs. 
 Brown & Co., from which large quantities of coal are also shipped 
 to Burlington and intermediate points. These mines are nearly a 
 mile to the north of the railroad, and the coal is brought to it on a 
 wooden side-track. There is good reason to believe that the land 
 between these mines and the railroad, as well as the land adjoining 
 these tracts, is underlaid by as good a bed of coal as that which 
 
REPORT OF STATE GEOLOGIST. 95 
 
 Brown & Co. are now working ; so that considerable supplies may be 
 expected here in the future for shipment and local use. No statis- 
 tics of the amount of coal shipped from the mines of this county on 
 the Burlington & Missouri River Railroad have been obtained, but 
 this trade is one of considerable importance. 
 
 From six to eight miles northward from Fairfield, on Walnut 
 creek, there have been quite a number of mines opened in a four- 
 foot bed of coal, and many more may be opened there whenever the 
 demand will warrant it. 
 
 There is so little demand for coal from these Walnut creek mines, 
 except in winter, that only one was found in operation. It is owned 
 and worked by Mr. Shaw, who was conducting the work in a very 
 creditable manner, and he will soon be able to supply a large 
 amount of coal. 
 
 Along Cedar creek, a few miles southward and southwestward 
 from Fairfield, several mines have been opened and many more may 
 doubtless be opened along the creek for several miles. Messrs. 
 Young & Stubbs have a good mine in operation four miles south of 
 Fairfield, in a bed which measures from three and a half to nearly 
 four feet thick. There is also another bed of coal overlying the 
 main one almost twenty feet. This bed being a little less than two 
 feet thick is thought to be unprofitable to work in view of the 
 abundance of coal in the county. It may be that this bed will be 
 found of profitable thickness elsewhere ; indeed it is not improbable 
 that the mine worked by Messrs. Heron & Richardson, may prove 
 to be in the same. If so, it is probable that another bed exists 
 beneath it. At Read's mill, three miles southwestward from Fair- 
 field, a good mine is in operation, and the coal is taken out from the 
 pit by the machinery of the mill. Along Walnut creek in the 
 northern part of the county there have been a number of mines open- 
 ed in a four - foot bed, and many more maybe opened there when 
 the demand will warrant it. 
 
 Our coal region needs long and careful study before any definite 
 estimate can be made of its productiveness, but the following are 
 some of the conclusions arrived at after the limited examinations thus 
 far made. The larger streams have generally cut their valleys down 
 
96 REPORT OF STATE GEOLOGIST. 
 
 to the limestone which forms the floor of the coal-measures, beneath 
 •which no coal may be expected. Thus no very deep mining will be 
 necessary in the region named. The larger streams have cut down 
 their valleys to, and through the coal beds, and nearly all the mining 
 is now done by drifting into their edges from the side of the valleys. 
 There is no doubt that the coal - beds are continuous beneath the 
 higher lands, and that they may be reached by the more expensive 
 method of shaft - mining whenever the demand will warrant it. 
 
 The Beds of coal lie so nearly horizontal beneath, and irrespective 
 of the general surface, that very safe calculations may be made in 
 the vicinity of those worked upon opening other mines at about the 
 same level in the neighboring slopes. 
 
 A little below Eead's mill, on land of Col. Thompson, there is a 
 good quarry of limestone from which some large and excellent stone 
 have been taken as may be seen in the basement wall of the new 
 building for the High School in Fairfield. Similar stone are also 
 found in the northeastern part of the county, but there are 
 comparatively few exposures of it. This is the limestone before 
 mentioned which forms the floor of the coal - measures, and conse- 
 quently it is useless to seek for coal beneath it ; and if in the future 
 sinking of shafts for coal, this limestone should be reached, the 
 work should be discontinued. 
 
 Overlying the coal at the mine of Messrs. Young & Stubbs, as well 
 as elsewhere in the county, is a deposit of soft sandstone, some 
 twenty feet in thickness. Most persons would pronounce it to be 
 too soft for use, but the former gentleman has an out -house built of 
 it which has stood unchanged for a number of years, and the hard- 
 ness of the stone has much increased upon exposure. It will doubt- 
 less serve a good purpose in the more inexpensive buildings, for 
 which the ease with which it is worked recommends it. 
 
 Fuel is so abundant in this county that there is good reason to 
 believe that timber is now growing faster than it is being used. The 
 excellence of the soil is too well known to need commendation from 
 me, and there is hardly one of the natural resources which the county 
 does not contain. 
 
REPORT OF STATE GEOLOGIST. 97 
 
 DUBUQUE LEAD MINES. 
 
 A short visit was made to these mines in July, for the purpose of 
 collecting data and material to supply deficiencies in our means for 
 investigating their mineralogy, and the methods of smelting the lead 
 ores'; and in some respects we were quite successful. 
 
 Some of these results have now a definite, practical value, but 
 others are, at present, only interesting scientific facts, yet we do not 
 know how soon they may assume practical importance. Among 
 the interesting facts which we obtained there, are several that have 
 long been known to the miners, but have never before been pub- 
 lished to the world. We are apt to forget that scientific knowledge 
 is only the knowledge of the few collected, arranged, systematized 
 and published for the benefit of all ; and that the knowledge of the 
 miner differs from that of the mineralogist only in degree, not in 
 kind. 
 
 Capt. Thomas Levin, an old and experienced miner of Dubuque, 
 who furnished much valuable information for the former Geological 
 Report, also first called our attention to the well - marked physical 
 difference between the lead ore of the east - and - west and the north- 
 and - south lodes. This difference is constant, easily recognized by 
 any person after his attention has been called to it ; and the fact is 
 a very interesting one, yet it has never appeared in print before, so 
 far as we are aware. Prof. Hinrichs is giving this matter its merited 
 attention, and hopes to derive some hints -from it concerning the 
 relative difference in the age of the two systems of crevices or lodes. 
 
 Mr. R. Simpson, of Rock Dale Smelting Works, also called our 
 attention to a grey substance in the ore obtained from a limited part 
 of one of the mines near Dubuque, which he finds to greatly retard 
 the process of smelting, and to diminish the product of lead. We 
 subsequently obtained good specimens of this ore at the mine, and 
 the Professor has already made analyses of the substance referred 
 to, which he finds to be carbonate of lead — the same in composition 
 as the grey substance often found coating the common ore. In this 
 cas5, however, it is disseminated throughout the mass of the ore, the 
 small cavities of which are often filled with crystals of the same 
 substance. The carbonate of lead when obtained in sufi&cient 
 13 
 
9g REPORT OF STATE GEOLOGIST. 
 
 quantities, is an excellent ore if smelted in a suitable manner, but 
 tbe process in use for the common ore (the sulphuret) is not suitable 
 for the carbonate, and the presence of the latter with the common 
 ore, seems to be worse than useless. This arises from the fact that 
 the carbonate fuses at a much lower temperature then the sulphuret, 
 flowing over the latter ore in the furnace, and prevents the compus- 
 tion of the sulphur which it contains and the consequent liberation 
 of the lead. The only modification of the common process which is 
 now in use for the smelting of this mixed ore, which he would 
 suggest, is to add small quantities of crushed charcoal at frequent 
 intervals during the smelting ; and even this he thinks of doubtful 
 value. 
 
 It seems improbable that large quantities of these mixed ores will 
 be obtained, and furthermore it is reasonable to expect that the 
 "grey slag" obtained in smelting it will contain more than the usual 
 quantity of " slag lead " which will be saved by the second smelting, 
 and the aggregate product may thus not fall so far short as the 
 diminished product of the first smelting would seem to indicate. 
 
 From the smelting works before mentioned, we obtained specimens 
 illustrating every stage of the process of washing and smelting, 
 including the sediment from the troughs, the difi'erent slags from the 
 furnace, and both " soft " and " slag " lead. 
 
 We also obtained specimens of quite a number of other mineral 
 substances which are usually associated with lead ore. From these, 
 and from examinations of the cabinets of several citizens of 
 Dubuque, Professor Hinrichs was able to make out the order of 
 occurrence of nearly a dozen difi'erent minerals ; or, to be more 
 explicit, it is known for instance that a certain mineral is found in a 
 crystalized form upon the surface of the rock, and that upon the 
 former, crystals of another mineral will be found, and still others 
 upon the last, &c. It is this order of occurrence of the difi'erent 
 minerals which is in part engaging the Professor's attention. 
 
 It was also our intention to obtain statistical information in rela- 
 tion to the present and past product of the mines, but we found that 
 perfectly reliable statistics of this kind were very difficult to obtain. 
 Indeed the oldest and best informed mining and smelting proprietors 
 
REPORT OF STATE GEOLOGIST. 99 
 
 were nlow to give a definite opinion upon this subject, although they 
 -were very willing to comply with our wishes in this respect as far as 
 possible. From conversation with these gentlemen I obtained the 
 following impressions, namely: that lead -mining is now in a toler- 
 ably prosperous condition, but there were times in its early history 
 when more ore was raised per man than now. The increased price 
 of lead makes mining as profitable now. as it ever was, although it 
 requires a greater proportion of labor and skill to obtain the ore 
 than formerly. 
 
 Little or no change has taken place in the methods of either min- 
 ing or smelting during the past twenty years, except the projected 
 drainage of the mines by means of adit levels. 
 
 An enterprise of this kind has been a couple of years in progress 
 by a New York company, and promises to be very successful. A 
 large area will be drained by this level when completed, which expe- 
 rienced miners believe will yield large quantities of lead ore, now 
 inaccessible on account of Jhe water. Should this enterprise succeed, 
 there are other regions near Dubuque which may be drained in the, 
 same manner with equally good prospects of success. A new era in 
 the history of Iowa lead - mining evidently depends upon the success 
 or failure of the company now operating. 
 
 Up to the present time there are no indications that deeper mining 
 will be profitable, or indeed in any degree productive in this region. 
 The thickness of the Galena limestone in the vicinity of Dubuque is 
 about two hundred and fifty feet, and the principal portion of the 
 lead ore is found above the middle of it, very little being found near 
 its base or top. The only exception at present known, is shown in 
 an'bpening recently made a short distance from the city by Messrs. 
 McCraney & Hlckok. Here these gentlemen have found a lead- 
 bearing crevice in the extreme upper part of the Galena limestone, 
 which has no cap - rock, the shales of the so - called Hudson river 
 group lying immediately upon the top of the fissure. What the 
 extent of this deposit of ore is, remains to be proven, as it had been 
 opened only a few days at the time of our visit. Upon some speci- 
 mens of lead and zinc ores thrown out from this mine, and also some 
 presented to us by the proprietors, we found numerous small crys- 
 tals of native sulphur. Sulphur in the water of springs is of course 
 
XQO REPORT OF STATE GEOLOGISl. 
 
 well known, but we believe this is the first discovery of native crys- 
 talized sulphur yet found in America, and its occurrence here is also 
 somewhat at variance with opinions which have been entertained 
 concerning the occurrence of sulphur in nature. Science is pro- 
 gressive, and why should not Iowa contribute her share to its pro- 
 gress ? 
 
 MARION COUNTY. 
 
 Every coal mine in this county which it was possible to enter, was 
 visited in person, although to accomplish this it was not unfrequently 
 necessary to wade in almost ice-cold water, which collects in the 
 mines when they are not v, orked. This is the condition of the 
 majority of them during the summer months, at which time there is 
 little demand for coal, there being at present no railroad through 
 that portion of this county which contains the largest amount. The 
 first mines visited were those of Messrs. Roberts, Fisher and Barnes, 
 near Otley station, on the Des Moines Valley Railroad, about seven 
 miles westward from Pella. They are situated on the upper branches 
 of a creek which empties into the Des Moines river, the two former 
 on section twenty - eight, township seventy - seven, range nineteen, 
 and the latter on section twenty - one, township seventy- seven, range 
 nineteen. The thickness of the coal in the mines of Messrs. Rob- 
 erts and Fisher, is from five to six feet. That of Mr. Barnes' mine 
 is four feet thick ; and being evidently in the same bed and nearer 
 the depot than the others, it has been suggested that the coal prob- 
 ably thins out in that direction, and that it would not be reached by 
 sinking a shaft at the depot ; but since coal, and probably the same 
 bed, has been discovered three feet thick several miles beyond the 
 depot in the same direction, there appears to be no good reason why 
 it should not be found of profitable thickness by sinking a shaft at 
 that point. There is evidently a large amount of coal in that part 
 of the county, a small portion only of which has been fortunately 
 exposed by the erosion of the creek valley before mentioned. Mr. 
 Nossaman, four miles southward from Pella, has opened a three - foot 
 bed of coal near the left bank of the Des Moines river, which, with 
 those before mentioned, are the only ones visited on the east side of 
 the river in this county. At Coalport, some four or five miles from 
 
REPORT OF STATE GEOLOGIST. IQl 
 
 Pella, Messrs. Bosquet & Thompson have opened a mine in the face 
 of the bluff immediately upon the right bank of the Des Moines 
 river, the coal of which measures from six to seven feet in thickness. 
 There is a band of cannel coal of several inches in thickness associ- 
 ated with the bituminous coal of this mine, but -which the water pre- 
 vented me from seeing at the time it was visited. This .bed of coal 
 appears in the face of the bluff as a broad black band ; and about ten 
 feet beneath it is a similar band about two feet wide, which repre- 
 sents another bed "of coal of that thickness. Making Knoxville a 
 point from which to work up the west side of the river, the mine 
 next visited was that of Mr. O'Neal, about two miles north of town, 
 on section nineteen, township seventy - seven, range nineteen. This 
 consists of two beds of coal, each about two feet thick, with a bed 
 of shale between them of similar thickness. The evidence that these 
 are two distinct beds of coal is increased by the fact that there is 
 much difference in the quality of each ; that of the upper being the 
 best, and much esteemed by blacksmiths. Going northward from 
 here about half a mile on the Red Rock road, we see in the face of 
 the bluff, composed of sandstone and sandy shale, immediately upon 
 the right bank of White Breast creek and near the mill, another bed 
 of coal two and a half feet thick. This last named bed is nearly on 
 a level with the mill - dam there, and probably represents the thick 
 bed of other parts of the county.' The depth at which this lies 
 beneath those of O'Neal's mine could not be definitely ascertained, 
 but it is probably not less than fifty feet. Going southward, imme- 
 diately at the outskirts of town, Mr. Brobst has a mine in operation 
 which measures four feet thick, and the same bed no doubt underlies 
 the whole town of Knoxville. 
 
 The next mines seen in this direction are upon the banks of 
 English creek, three or four miles from town. The coal in these 
 mines measures from three to four feet in thickness. And the coal 
 is exposed at frequent intervals along the hillsides bordering this 
 creek, until they merge in those which border the bottom lands of 
 Des Moines river. The bed of coal in which the last named mines 
 are opened, evidently thickens in the direction of the course of the 
 stream, that is, to the eastward, and" probably also to the southward. 
 This is clearly seen in the vicinity of Bussing's mill, four miles east 
 
j^Q2 KBPORT OF STATE GEOLOGIST, 
 
 of town, where it has reached a thickness in some places of seven 
 feet. The mines which have been opened in the vicinity of this mill, 
 upon English creek and its branches, have from five to seven feet in 
 thickness of coal. At the mines owned by Messrs. Sherman, New- 
 man and Ferrin, about a mile southward from the mill, the coal is 
 from five to six feet thick, and about fifteen feet beneath this, another 
 bed of coal is seen cropping out in the bed of the small creek, which, 
 however, is only about eighteen inches thick. Quite a number of 
 mines have been opened in the hills in the vicinity of this mill, the 
 coal of which is usually compact in most of them. While this 
 character renders the mining of it a little more diflScult, it will be 
 more valuable for shipment because it will not crumble so easily ; 
 beside which, the more dense the coal is the more heating power it 
 possesses if it is pure coal, which this seems to be. When an east 
 and west railroad is built through this county it will probably pass 
 up the valley of this creek, when the coal lands there will be very 
 valuable, and the supply of coal for shipment will be immense. 
 Numerous points along White Breast creek were visited where coal 
 had been mined, which indicated that the supply that may be 
 obtained along that stream is very great. A bank was visited some 
 six miles southwestward from town, near this creek, from which 
 considerable quantities of cannel coal are said to have been taken, 
 but not now being worked it had unfortunately fallen in so that only 
 a few fragments of the coal could be obtained. Although coal may 
 doubtless be obtained in almost any part of the county, the south- 
 eastern quarter of it is pre - eminently its coal region. Perhaps, 
 however, this is only apparently so, and that just as heavy beds of 
 coal exist in other parts, the streams of which have not cut their 
 valleys deep enough to expose them as they have in the southeast-, 
 ern quarter, which will be presently explained. Along the hillsides 
 which skirt the North and South Cedar creeks from their entrance 
 into the county to where they unite and enter the bottom land of the 
 Des Moines river, a bed of coal is found naturally exposed at 
 frequent intervals, which measures from five to seven feet in thick- 
 ness and sometimes more. This region has now only a local country 
 market for its coal, so that little more is yet done in the way of 
 mining it, than to dig into the exposures to ascertain its thickness. 
 
REPOKT OF STATE GEOLOGIST. 103 
 
 The thickest bed of coal found there, and so far as at present 
 known, the thickest in the State, measures nearly ten feet in 
 perpendicular thickness, the room in the mine being higher than 
 many of the rooms of our dwellings. This mine belongs to Mr. 
 Jacob Kline, and is located on section twenty - nine, township 
 seventy - four, range eighteen. About three feet from the top 
 of the bed of coal there is a band of shale a couple of inches 
 thick, which suggests that there may in reality be two separate 
 beds which at this point have come together. 
 
 Marysville, a cosy - valley village which has been built up by an 
 intelligent and industrious community, composed principally of 
 Pennsylvanians, since most of our maps were made, is situated upon 
 the same section. Here two other mines are opened and worked 
 with only sufficient force to supply the neighborhoods and the mills of 
 the village. The first is owned by Mr. John Yenser, and the other 
 by Mr. D. F. Leiby. A couple of miles below the village Mr. Gr. H. 
 Clemens has made an opening in the same bed. The coal at Marys- 
 ville is seen in the face of the bluff on the right bank of the creek 
 in much the same position as that at Coalport before mentioned; and 
 a similar bluff exposure of the same bed is seen on the right bank 
 of North Cedar creek, on land belonging to Mr. A. P. Chambers, 
 section sixteen, township seventy - four, range eighteen. Farther 
 down the creek, on land of A. B. Lyman, Esq., there 
 are other exposures of coal, but the want of a market has 
 prevented them from being worked. Beside these and numerous 
 other exposures of coal along the two Cedar creeks there are 
 many others along the hillsides which skirt the bottom land of 
 the Des Moines river. Mr. Daniel Sherwood, a couple of miles 
 southward from Attica, is working one upon a branch of North 
 Cedar, evidently in the same bed as the others just mentioned. 
 
 Although that member of the sub - carboniferous limestone series, 
 known among geologists as the " St. Louis limestone " is found in 
 the bed of, and skirting the Des Moines river almost all the way 
 from a few miles below the state capital to Keosauqua, and is often 
 a very good building - rock, yet the same bed, when found in the 
 vicinity of Pella is somewhat different in texture from that of almost 
 all the exposures of it yet seen. At other localities, although often 
 
104 KEPORT OF STATE GEOLOGIST. 
 
 in distinct and massive layers, it is usually very compact and brittle, 
 breaking in such an irregular manner that it is dressed with great 
 difficulty, yet in all cases furnishing a superior quality of lime. That 
 of the Pella quarries is regularly bedded, and is not only wrought with 
 great facility, being free from flinty material, but is evidently very 
 durable as well as of a pleasing appearance when dressed. The 
 quarries have a thickness of from eight to ten feet, the upper half of 
 which is usually in rather thin layers, which are valuable for lime 
 and all the purposes of common masonry ; but the lower half is 
 formed of the excellent material referred to, which may be quarried 
 with comparative ease, in all the forms and sizes usually desired. 
 
 Although the stone varies a little in texture and appearance at 
 each of these quarries, there is abundant evidence that they are 
 portions of the same continuous beds, which also underlie the inter- 
 vening region, although covered too deeply by soil and drift mate- 
 rial to be accessible. 
 
 The texture of the massive layers in the quarries south - westward 
 from the town is inclined to be oolitic — a term used to indicate a 
 rock composed of small spherical particles resembling the roe of 
 fishes — while the same beds two and a half miles north of town, four 
 feet in thickness, are made up entirely of the fossilized, cast - off 
 shells of a minute bivalve crustacean. {BeyrioTiia pefrifador.) 
 
 A mile and a half northward, the same beds, are seen in the quar- 
 ries of Mr. Phillip Mather, and there present a dense, fine - grained 
 texture of excellent quality for dressing, and ot a lighter grey color 
 than the others. From these quarries, beside specimens of each 
 variety of the rock, a good collection also of the fossils which 
 characterize this member of the sub - carboniferous limestone series, 
 were obtained to add to the State Cabinet. 
 
 Mr. W. Nossaman has some excellent quarries, both for lime and 
 dressed stone, almost four miles south of Pella. His coal mine, 
 before mentioned, is only a few rods distant from his quarries, the bed 
 of coal lying some twenty -five feet above the limestone, so that he 
 runs the coal from his mines to his lime - kilns without any further 
 transportation. 
 
 The limestone, although not the upper member of the full series 
 of sub - carboniferous strata, is yet the upper member of that series 
 
REPORT OF STATE GEOLOGIST. 105 
 
 in our own State, and the coal - measure strata throughout the Des 
 Moines Valley are found resting upon it. Consequently it is useless 
 to look for coal beneath this rock, judging from all the experience 
 ■which geology has yet furnished us. Throughout the greater part 
 of Marion county however, this rock lies so deep beneath the surface 
 as to give space between it and the surface for those important 
 deposits of coal before described. The sandstone of this county 
 belongs to the coal - measures, and of course overlies the limestone. 
 Much of it is soft, at least when first taken from the quarry, yet it 
 hardens considerably when exposed for a short time to the atmos- 
 phere. 
 
 There are, however, large quantities of this sandstone that is hard 
 enough for any purpose as a building material. The principal 
 of these firm exposures of sandstone are found at, and near 
 the village of Red RocTs:, on the Des' Moines river, although sand- 
 stone equally good, but of a different color, is found in various parts 
 of the county. This stone at Red Rock assumes the character of 
 a clean grit sandstone, most of which is of a bright brick - red color. 
 The exposure here is a bold bluff, reaching a height of about seventy 
 feet. In some few places the stone appears to be soft, but the 
 greater part of it is quite uniform in hardness, and the layers so mas- 
 sive that blocks of almost any desired size can be quarried. Much 
 of this stone has already been used in various places, and a part of 
 that used in the construction of the State Arsenal was obtained from 
 these quarries. On the opposite side of the river valley from Red 
 Rock there are similar blufi's of the same sandstone, which presents 
 nearly the same colors. The same exposure also is seen in a gradu- 
 ally diminishing bluff bordering the valley along several miles below 
 Red Rock. 
 
 Some large and small concretionary masses of what geologists call 
 quartzite were found at Red Rock and other places in this county, 
 embedded in, and forming a part of the sandstone - deposit, the lines 
 of stratification running without interruption through each, showing 
 that the quartzite is a part of the same deposit. To produce this 
 change of sandstone in nature it was once supposed that great heat 
 U 
 
106 REPORT OF STATE GEOLOGIST. 
 
 was necessary; but we have no evidence that any of the accessible 
 strata of Iowa have been altered by he?t. 
 
 The limestone before described doubtless underlies the whole of 
 Marion county, but only appears where slight undulations have 
 brought it up, or where the streams have cut their valleys down 
 to it through the coal - measure strata. The coal - measures, com- 
 posed of sandstone, shale, clay and coal, lie comformably upon this 
 limestone, and follow it in its dips and undulations. Upon the coal- 
 measure strata rests the dritt material, a part of which forms the 
 soil and sub - soil. 
 
 The original horizontal position of the limestone and coal -measure 
 rocks has been but slightly changed in this county, and are quite 
 independent of any inequalities of the present surface of the earth, 
 because those inequalities are due to the erosion of the valleys by 
 the streams which run through them, thereby cutting down through 
 each successive stratum, the edge of every one of which would be 
 seen in the sides of the valleys if it were not that they are cov- 
 ered by the soft material derived from their disintegration. Thus 
 we find exposures of coal only where they have been cut through in 
 this manner by the streams, and thus the conclusion is perfectly 
 legitimate that the same beds of coal extend continuously beneath 
 the high lands, whose edges we see upon each side in the valleys. 
 The question often arises as to how many different beds of coal there 
 are in this county. This question can - not be answered in a perfectly 
 satisfactory manner until the whole region has been carefully and 
 minutely examined, which will be a work requiring far longer time 
 to accomplish than can now be given to it. 
 
 The conclusion arrived at from the partial examination thus far 
 made is that there are in Marion county at least three separate beds 
 of coal, the middle one of which is much the most important and 
 extensive. The others seem to thin entirely out in some places, so 
 that it is doubtful whether they would all be pierced by a boring 
 made at any one point ; yet there is probably no point upon the high 
 lands of this county which is not underlaid by more or less coal. To 
 be a little more explicit, it may be stated that the double bed — 
 counted as one — of Mr. O'Neal's, is regarded as the highest, and 
 
REPOKT OF STATE GEOLOGIST. IQJ 
 
 that the thick one in which the mines pf Coalport, English, Cedar 
 and other creeks are opened, is believed to be the second, and the 
 thin one beneath the last -named bed, as seen at Coalport and also 
 a mile south of Bussing's mill, would consequently be the third. 
 The first occurs apparently above the principal sandstone horizon, 
 and the second, a main bed, just beneath it. This horizon does 
 not always present firm exposures of sandstone, as at Ked Rock, 
 Eagle Rock, Bussing's mill, a mile above Marysville, &c., but may 
 be seen in the form of yellow comminuted sandy shale, upon the 
 sides of the hills in many places — more, perhaps, than where it 
 appears as firm rock. Thus, if one should sink a shaft with a view 
 of reaching the main bed, after passing through the upper bed, as 
 Mr. John Gamble has done in digging a well at his residence just 
 north of Knoxville, where he found it four feet thick at a depth of 
 thirty feet, he would then pass through a considerable thickness of 
 either sandstone or sandy shale. If he were seeking the position of 
 that bed upon the hillside, he might espect to find it near the base 
 of that sandy horizon, whether of sandstone or sandy shale. The 
 sub - carboniferous limestone before mentioned can not lie \erj deep 
 beneath any part of the county ; consequently no very deep mining 
 will be necessary in any part of it. It is thought that a shaft of two 
 hundred feet at any point in the county will reach all the coal to be 
 found. The time will come when it will pay to sink such shafts from 
 the highlands to obtain the coal from the extensive beds which are 
 thus far only very slightly penetrated from their edges. 
 
 The quality of the coal of this county is fully equal to the average 
 of Western coal, and that of many of the mines is in excellent 
 repute among blacksmiths for working iron. 
 
 Marion is one of the best supplied counties in the State for 
 timber. Much of the original forest yet remain along the streams, 
 and the young timber is growing vigorously wherever it is allowed 
 to stand. The prairies are comparatively small, and beautiful groves 
 of native trees are scattered almost everywhere, giving a very 
 pleasing efi'ect to the landscape. The streams being numerous, the 
 county is well watered, besides which, wells of good water are 
 easily obtained at moderate depth almost anywhere, some of which 
 have penetrated beds of coal. It would be superfiuous to add 
 
103 REPORT OF STATE GEOLOGIST. 
 
 anything in praise of the fertility of the soil to those who see the 
 bountiful harvest which is now everywhere burthening the fields. 
 
 WAPELLO COUNTY. 
 
 The examination of this county was commenced in the western 
 part, on the south side of the Des Moines river, and the first, mine 
 visited was that of C. Dudley & Company, on section four, seventy- 
 two, fifteen. Judging from what is now to be seen of this mine its 
 coal will prove to be unsurpassed by any other now offered in the 
 market, and these gentlemen will soon be able to furnish very large 
 quantities. The bed is four feet thick, and very uniform in quality. 
 They are now constructing a tram road from their mine to the track 
 of the Burlington and Missouri Railroad, a little less than a mile 
 distant. About half a mile southward, from this mine an opening 
 has been made in what appears to be the same bed, but the quality 
 of the coal now obtained is poor, and I fear the prospect is not 
 flattering that it will improve much within a short distance. A 
 quarter of a mile westward of Dudley & Company's mine an opening 
 in the same bed is being made with good prospect of finding 
 excellent coal. The bed in which the last named opening has been 
 made, as well as that of Dudley & Company, is the second in the 
 serfes, as may be seen by going down the creek a few rods, where 
 the limestone — which, as said in previous letters, forms the floor 
 of the coal - measures, and beneath which no coal need be sought 
 for — is found in the bed of the creek. About three feet above this 
 limestone is seen a bed of coal which is here only about one and a 
 half feet thick, and which is of course the lowest in the series. 
 Above this bed of coal is a space of about forty -five feet, the 
 material composing which is partly hidden by the slope of the hill ; 
 and upon this rests the four - foot coal bed of Dudley & Company's 
 mine. On the north side of the creek (North Avery) a little more 
 than a mile from the last named mine, Mr. J. G. Heacock has 
 opened one in a four -foot bed of coal, but since the before mention- 
 ed limestone is seen exposed in the slope only about five feet beneath 
 the coal there, no doubt is felt that this is the lower bed of coal, and 
 therefore not identical with that of the mine of Dudley & Company, 
 but with the thin one which lies forty - five feet beneath it. Mr. 
 
REPORT OF STATE GEOLOOiBT. 109 
 
 Heacock has only just opened his mine, and the quality does not 
 seem to be as good as some others, yet it will no doubt make good 
 fuel for steam purposes. It is reasonable to suppose, however, that 
 the quality will somewhat improve as the mining proceeds beneath 
 the hill, but there is also reason to believe that the coal of the 
 
 r 
 
 second bed will be found to be better than that of the first, at least 
 in this part of the county. Going down the river valley three miles 
 below the village of Chillicothe, to the mines of Henry Shock & 
 Company, on section eight, township seventy - two, range fourteen, 
 the coal was found to be of good quality, and the bed five feet thick. 
 These gentlemen furnish a large amount of coal for shipment on the 
 B. & M. Railroad. About a quarter of a mile further up the small 
 creek which comes into the Des Moines river there, and upon the 
 same section, Mr. David C. Evans has just got a mine into good 
 working order in the same bed of coal, which here also measures five 
 feet in thickness, and the quality fully equal to that of Shock & 
 Company. There is no doubt that the high lands bordering this 
 creek and the adjacent high lands bordering the Des Moines river 
 bottom are underlaid by as good coal as is seen in the mines just 
 mentioned. 
 
 In the immediate vicinity of Ottumwa several mines have been 
 opened, but the beds are rather thin and the quality poorer than the 
 coal of the county will average, although they furnish a considerable 
 amount of good coal. The first and second beds of coal are repre- 
 sented in the hills at Ottumwa, but yet it seems probable that the 
 principal supplies for the city must he brought from mines four or 
 five miles distant. About that distance to the northwestward from 
 the city, on section thirty - three, township seventy - three, range 
 fourteen, Messrs. Brown & Godfrey have some mines in operation 
 from which they are preparing to ship large quantities of coal. Both 
 the D. V. and B. & M. Railroads run near each other within a mile of 
 their mines which will give them- unusual advantages in shipping 
 coal to various markets on both roads. The quality of their coal is 
 good, and the bed measures from four to four and a half feet thick. 
 Northwestward from these mines, and about a mile southward from 
 Kirkville, several other mines have been opened, all apparently in 
 
2]^() . REPORT OF STATE GEOLOGIST. 
 
 the same bed. Those latterly known as Smith's mines have been on 
 fire for several months, probably the work of an incendiary, but are 
 now nearly extinguished. The coal of these mines has long been in 
 good repute, and Mr. Smith will soon have them in working order 
 again. Mr. Joshua Marshall has a good five - foot mine in good 
 condition on section seventeen, township seventy - three, range 
 fourteen, and has a good local market for his coal. In the immedi- 
 ate vicinity of Eddyville several mines are worked in a bed which 
 ranges from three to four and a half feet in thickness. From these 
 mines some specimens of coal were obtained as fine as any I have 
 seen in the West. An exposure of cannel coal was reported to exist 
 in the immediate bank of the Des Moines river, about half a mile 
 above the town, but the river was too high at the time of my visit to 
 see it. From indications observed in the northwestern quarter of the 
 county there is reason to believe that this region will furnish very 
 large quantities of excellent coal for export, which may be readily 
 run down to the railroads by branch tracks laid along the numerous 
 small streams which empty into the Des Moines river. This will 
 make Wapello one of the principal exporting coal counties of the 
 State; indeed, more coal is now shipped upon the Burlington & 
 Missouri Railroad from this county than from any other through 
 which it passes. 
 
 Thus far very little coal has been found in the southwestern and 
 northwestern quarters of the county, but in the former, if not also 
 in the latter, it is probable that coal may be found at a moderate 
 depth beneath the surface, but down to which the valleys of the 
 creeks, being small ones, have not been cut, as has been the case 
 along the river and the larger creeks. A large amount of coal, 
 however, is found in the southeastern part of the county, the princi- 
 pal mine of which is worked at Alpine Station, on the D. V. Rail- 
 road by the Alpine Coal Company, under the direction of Mr. 
 
 C. J. Love. 
 
 This mine furnishes large quantities of coal for the Keokuk 
 market, where it is in good repute, being shipped there upon the 
 
 D. V. Railroad. The bed is from four to five feet thick, and since 
 the mine was opened it has furnished about one million bushels of 
 
REPORT OF STA.TB GEOLOGIST. m 
 
 coal, which is probably more than the product up to this time of any 
 other mine in the State. 
 
 The St. Louis limestone without doubt underlies the whole of this 
 county in the same manner that it underlies those described in the 
 preceding pages. It is exposed at numerous points along the Des 
 Moines and its tributaries at and above Ottumwa. It furnishes 
 excellent material for lime, and also good building rock, much of 
 which is suitable for dressing. 
 
 Below Ottumwa the limestone rapidly dips beneath, so that the 
 coal -measure sandstone is seen near the water's edge, a mile below 
 town, and just below Alpine station, eight or nine miles from Ottumwa, 
 a bed of coal is found in the bed of the river. The sandstone referred 
 to, is of the same general character as the coal - measure sandstone 
 before spoken of, but it is not quite so firm, nor so uniform in quality 
 as that obtained at Red Rock. It will hardly be used where good 
 limestone can be easily obtained, but yet much of it will answer well 
 the purposes of common masonry. 
 
 Usually the strata of the Iowa coal - field, as well as the underlying 
 sub - carboniferous limestone, are very regular and undisturbed, but 
 commencing a little above Ottumwa and going down the valley there 
 is seen to be considerable evidence of disturbance of the strata. 
 
 This disturbance has not been violent, but yet sufficient to pass the 
 limestone beneath the level of the river just below Ottumwa, so that 
 it does not appear again below that point in this county. At 
 the Alpine mines below referred to, the coal and its associated beds 
 also partake of the disturbance so that the bed of coal is entirely cut 
 off at one place within the mine, by what seems to have been a settling 
 of the superincumbent mass in longitudinal folds, the folds having a 
 general direction from northeast to southwest. A number of these 
 folds have been met with in the mine, depressing the roof, but only 
 one of them has been found to cut the coal entirely off. Judging 
 from the character of the others, the miners may expect to find the 
 coal again after passing a short distance through the material which 
 now occupies its place. The cause of these disturbances is not at 
 present clearly seen, from the fact that the efiects have not been 
 traced in a longitudinal direction over a considerable extent of 
 country as they usually may be in such cases. 
 
Ii2 REPORT OF STATE GEOLOGIST. 
 
 Thus far no similar evidences of disturbances of coal - measure 
 strata have been observed in Iowa, although the older rocks in the 
 adjoining States are often found disturbed. 
 
 No minerals of value except coal, have been discovered in this 
 county, and it is hardly probable that any such will be found. Small 
 quantities of iron ore have been found in this, as well as in many 
 other of the coal counties. It is usually in the form of small, irreg- 
 ular, lenticular masses, called clay -iron stone, Or in still mere irreg- 
 ular masses of per - oxide of iron, usually called red haematite. The 
 latter is an excellent ore of iron, but to be profitable it must exist in 
 large quantities and easy of access. One can not fail to see that 
 these small quantities of iron ore, however excellent, are valueless 
 when he learns the fact that iron ore is now being shipped from the 
 famous Lake Superior mines to the furnaces in north - eastern Ohio 
 and north - western Pennsylvania, which were built for smelting the 
 ores of their own regions. Upon the completion of our iiorth and 
 south railroads the iron region of Missouri will supply us much more 
 cheaply than we could produce that metal, even if our supply of'ore 
 were many times greater than it is. In the fissures of the clay- 
 iron nodules founjl in the dark shale just north of Ottumwa, small 
 quantities of the sulphuret of zinc were found. This discovery is 
 valuable, however, only as an interesting fact in mineralogy. 
 
 Wapello county is well supplied with timber, which will always 
 keep wood at a reasonable price for those who prefer it to coal as a 
 fuel. It is well watered by the Des Moines river and its numerous 
 tributaries, as well as by numerous excellent springs. Good wells 
 are easily obtained almost anywhere. It is superfluous to say that 
 the soil is excellent, for no poor soil exists along the great valley of 
 the Des Moines. 
 
 VAN BUREN COUNTY. 
 
 Van Buren was one among the first counties in the State known 
 to contain coal, consequently some of the oldest mines in the State 
 are found here. It was quite fully reported upon by Prof. Worthen 
 in the reports of the former geological survey ; and the principal 
 object of my visit there was only to obtain some more definite ideas 
 in relation to its coal. ' 
 
REPORT OF STATE GEOLOGIST. 
 
 113 
 
 Commencing in the north - western part of the county, all the 
 mines were visited in succession which were in a condition to enter. 
 The first was McHugh's mine, on section seventeen, township sev- 
 enty, range eleven, a little below the town of Independent. The 
 bed is about three feet thick, but is not now much worked. 
 
 Two and a half miles eastward from the last named town, on sec- 
 tion ten, township seventy, range eleven, Mr. Rodefer has a good 
 mine in operation, the coal of which is of good quality and the bed , 
 four feet thick. On the same section, and about half a mile further 
 up the small creek upon which the Rodefer mine is situated, there is 
 another exposure of a four-foot bed of coal, the identity of which 
 with that of Rodefer's mine seems impossible, as it is evidently many 
 feet above it. 
 
 Upon a branch of the same creek, near the last-named exposure, 
 another is seen about one foot in thickness, which seems to be sepa- 
 rate from both the others, probably lying between them. Should this 
 supposition prove correct, there are three separate beds of coal in 
 this county, all of which are to be seen upon section 10, township 
 70, range 11. The thin bed just mentioned is overlaid by shales of 
 the same character and containing the same species of fossil fish 
 remains as the upppr bed does in Wapello and Monroe counties. 
 Half a mile south of Business Corners, Mr. Alexander Findley is 
 working a mine in a three-and-a-half-foot bed, which has supplied a 
 large district around for many years. About a mile from the latter 
 mine, on lands of Hon. Eliab Doud, at Doud's Station, several open- 
 ings were formerly made, and a considerable quantity of coal taken 
 out. They are now abandoned, although much good coal may doubt- 
 less yet be obtained here. 
 
 At and in the vicinity of Keosauqua several openings have been 
 worked for a long time, but to the extent only of supplying the local 
 demand. The bed ranges from two to three feet in thickness. These 
 openings are all upon the right bank of the river, but there seems to 
 , be no good reason why the same bed should not be found beneath 
 the higher lands of the great bend in which Keosauqua is situated, 
 where they are above the level occupied by the limestone. 
 
 Coal has formerly been mined at several points along Chequest 
 
 creek, but operations are now suspended there. 
 15 
 
124 KEPORT OF STATE GEOLOGIST. 
 
 A couple of miles northward from Bentonsport, Mr. Carter is 
 working a three -foot bed of coal, and several other openings have 
 also been made in that township. 
 
 At Farmington very large quantities of coal were formerly mined 
 for shipment on the Pes Moines Valley Railroad to the Keokuk and 
 other markets. On the south side of the river there the principal 
 mines are owned by Messrs. Dibble, Wright & Tuttle, and no doubt 
 they can yet be made to furnish large quantities of coal whenever 
 the demand will warrant it. 
 
 On the north side of the river, a mile above Farmington, a New 
 York Company own and formerly worked extensive mines, having a 
 branch track from the railroad. In the northeastern corner of the 
 county, near Hillsboro, several mines have been worked for several 
 years to supply a local and northward market. Mr. Martin has a 
 mine on section fourteen, township seventy, range eight, said to be 
 seven feet thick, but learning that it was not in a condition to enter, 
 it was not visited. There is evidently much coal in Van Buren 
 county, but at present it is only worked to supply local demand. 
 
 Both the magnesian and calcareous members of the St. Louis lime- 
 stone (sub - carboniferous) are freely exposed along the valleys of the 
 Des Moines and its larger tributaries. This is particularly the case 
 from Independent nearly to Bentonsport. At the latter place the 
 Keokuk limestone appears beneath the St. Louis limestone, the latter 
 there appearing near the tops of the hills. The same limestones are 
 also seen in similar positions at Bonaparte, but upon reaching Far- 
 mington the Keokuk limestone has dipped down beneath the river 
 again, and the St. Louis limestone is seen occupying a position near 
 the water level. 
 
 It is always found that when these sub - carboniferous rocks are 
 elevated, the coal - measure strata which rest upon them are also 
 elevated with them. This proves that the elevation took place since 
 the coal - measure strata were deposited, and since these have often 
 suffered denudation, it is believed that this was accomplished by 
 glacial action, and consequently the elevation of the strata took place 
 before the glacial epoch. 
 
 In this county the limestones also show considerable evidence not 
 only of unevenness of surface at the time of the deposition of the 
 
REPORT OF STATE GEOLOGIST. 215 
 
 coal - measure strata but also of some disturbance during the time of 
 its own deposition. This is shown by the brecciated character of 
 the rock in many places, and also by the evidences of the fracture 
 and slipping of some portions past the other, producing something 
 approaching to what are called faults. These fractures are always 
 lodal, and can not be traced to any considerable distance, as faults 
 usually can. During the deposition of the rock the disturbance was 
 often so great as to break up the continuity of the beds and mix 
 masses of limestone with the sandstone of the same formation, as 
 may be seen above Thatcher's mill near Keosauqua. 
 
 These disturbances, together with the erosion which the formation 
 seems to have suffered before the deposition of the coal - measures, 
 left the general surface so uneven then that it has had the effect of 
 causing a want of uniformity in the thickness of the beds of coal and 
 also of their associated strata. Thus in this county, even where the 
 continuity of the coal - beds can be made out, they are found to be 
 in good workable condition in some places, and so thin in others as 
 lo be worthless. Thus the best mines of this county may be expected 
 to occupy limited but not necessarily entirely isolated basins. 
 
 The St. Louis limestone presents at least three distinct subdi- 
 visions in Van Buren county, which are more distinctly seen in 
 Keosauqua than elsewhere. The first presents the usual charac- 
 ters of that limestone ; is about twenty - five feet thick, and imme- 
 diately underlies the coal - measure strata there, as usual in other 
 parts of the coal - field. The second is a sandstone about twenty 
 feet in thickness, and is seen well exposed just above Thatcher's 
 Mill, where it underlies the first. This sandstone is sometimes 
 soft and shaly, but near the residence of Hon. J. Thatcher it pre- 
 sents quite a firm texture, and has the general appearance of the 
 coal - measure sandstone before mentioned, but is lighter colored. 
 Most of it will doubtless serve a good purpose for ordinary build- 
 ings, and being quarried with much less labor than the ordinary 
 limestone, it will probably be found desirable for many purposes; 
 The third division is magnesian limestone, and is to be seen at the 
 water's edge below the dam at Kinnersly's Mill. 
 
 On Lick creek, near Kilbourne station, on the D. V. Railroad, 
 Messrs. Knapp and Wright, of Keosauqua, own extensive quarries 
 
IIQ REPORT OF STATE GEOLOGIST. 
 
 of light - brown stone, which belong to th emagnesian portion of the 
 sub - carboniferous limestone. These rocks were extensively quarried 
 manv years ago for the Des Moines River Improvement. Bridge 
 abutments built then of these stone are standing now entirely 
 unchanged, showing that the material is excellent for such pur- 
 poses. 
 
 The layers are massive, yet they are easily worked and may be 
 obtained of almost any desired size. They are of two distinct varie- 
 ties, although both possess nearly the same color ; the lower layers 
 being properly magnesian limestone, and the upper layers being 
 more properly an arenaceous limestone with a little carbonate of 
 magnesia. Both derive their brown color from iron. Both varie- 
 ties will make good building material, but I think the arenaceous 
 variety a very superior stone for heavy masonry. 
 
 The upper limestone also furnishes much good building - rock, and 
 also excellent lime. Messrs. Castor & Tuttle have a lime - kiln just 
 opposite Keosauqua, and upon the same ground a coal - mine, from 
 which they obtain the fuel for burning the lime. 
 
 On the farm of Mr. A. W. Mangum, two and a half miles from 
 Keosauqua, a good bed of fire - clay is found, from which the prin- 
 cipal supplies are obtained for the pottery of Mr. R. M. Dickson, at 
 Vernon. Mr. Dickson employs twenty hands and uses two kilns, 
 manufacturing all kinds of common pottery, and also drain - tiles. 
 
 No minerals of practical value, except coal, have been found in 
 Van Buren county, nor does it seem probable that any such will be 
 found. Samples oi good iron ore — red haematite — were obtained 
 from lands of Hon. J. Thatcher and Mr. Trebblecock, near Keo- 
 sauqua, but there is no prospect that it will be found in sufiicient 
 quantities for profitable manufacture. Indeed, the Missouri and Lake 
 Superior iron regions seem destined to supply the whole West with 
 iron ; for their ores are now carried long distances to be smelted 
 with profit in furnaces which were built for the purpose of smelting 
 ores from the grounds they stand upon. 
 
 Some citizens of Farmington within the last two years have bored 
 an artesian well to the depth of seven hundred and five feet. It is 
 now discharging water very freely, although the boring is not tubed. 
 It has been conducted in i tube to a hight of forty feet above the 
 
REPORT OF STATE GEOLOGIST. 117 
 
 top of the well, still discharging freely. Thus far no use has been 
 made of it. The temperature of the water is much above that of 
 common well - water, and appears to taste slightly of sulphuretted 
 hydrogen. 
 
 Hon. C. G. Dibble kindly forwarded a quantity of it to the labo- 
 ratory for analysis, but the vessel containing it was unfortunately 
 b'-oken in its passage, and no opportunity has since presented itself 
 for obtaining more. 
 
 Mr. J. J. Kinersly, in digging a well on his farm a mile northward 
 from Keosauqua, came down upon coal - measure shale within fifteen 
 or twenty feet of the surface. Water, presenting no unusual color, 
 came in somewhat freely, having a very acid and acrid taste, so that 
 he abandoned the well for ordinary purposes. An analysis of this 
 water shows it to be very strongly impregnated with proto - sulphate 
 of iron — common copperas — with some free sulphuric acid. The 
 substances contained in this water are so cheap in the market that 
 they may in this case be considered entirely worthless. The deep - 
 red liquid seen standing in puddles about the &ouths of coal-mines 
 is of the same general character as that of Mr. Kinersly's well, 
 except that the per- oxidation of the iron gives it the dark color. 
 
 MARSHALL COUNTY. 
 
 The reason why this county is so briefly reported upon, or rather 
 why it is not reported upon at all at the present time, is because it lies 
 directly in the path which it was necessary to travel to reach that 
 portion of the State which it was proposed to examine for peat The 
 immediate surface of the greater part of Marshall county is under- 
 laid by sub - carboniferous rock, beneat hwhich no coal need be sought 
 for but upon which the coal - measure sandstone is seen to rest at 
 some points in the vicinity of Linn creek. 
 
 This sandstone and its associated shales has no aoubt a consider- 
 able development just beneath the surface drift and soil of the 
 western and southwestern part, although they may not be exposed 
 to view. The general dip of all the strata being to the southward, 
 these coal - measure strata would be expected to increase in those 
 directions, while the sub - carboniferous rocks before mentioned, pass 
 
218 KEPORT OF STATE GEOLOGIST. 
 
 beneath them and are seen no more. In defining the borders of a 
 coal - field, geologists designate a line upon the map within which 
 those rocks are found exposed that are known to be associated with, 
 and of the same geological nature as the coal, although no coal may 
 be discovered by them, or even if none actually exists there. Thus 
 we know that the border of the Iowa coal-field so determined runs 
 through Marshall county in a southeasterly and northwesterly 
 direction. 
 
 Although there are some instances of a considerable development 
 of coal within a short distance of the well defined - border of the 
 coal field as above described, as for example near Eldora in Hardin 
 county, yet such favorable exceptions are not often to be expected. 
 While it is not at all impossible that coal may be discovered in the 
 western and southwestern portions of the county, yet in view of the 
 facts just mentioned, justice requires that I should not encourage a 
 large expenditure of money or labor in the search for it. 
 
 The rocks of the eastern and central parts of the county 
 have been spoken of as sub - carbaniferous. There are several 
 distinct formations which constitute the rocks of sub - carboniferous 
 period, inost of which are found in our State. These are first — and 
 lowest in the series — these rocks and their geological equivalents 
 which are seen at the base of the exposures at Burlington, and called 
 by the Illinois geologists the "^Kinderhook group ; " next the 
 "Burlington limestone ;" next the " Keokuk limestone ; " next and 
 highest in the series in our State, the " St. Louis limestone. " It is 
 the latter that the coal - measure rocks of Iowa are usually found 
 resting upon ; but the sub - carboniferous rocks of this county are 
 geologically equivalent to the upper part of the Kinderhook group, 
 and perhaps also to the lower part of the Burlington limestone. 
 
 Consequently the coal - measure sandstone which rests upon the 
 limestone in this county is in geological language unconformable to 
 it, because the upper Burlington limestone, Keokuk, and St. Louis 
 limestones are all wanting from their places between the two. 
 
 The county is well supplied with stone for building purposes and 
 for lime, from the limestone before mentioned, and the coal - measure 
 sandstone is also used for rough masonry to a limited extent. The 
 general surface is of a pleasing and gently undulating outline, and 
 
REPORT OF STATE GEOLOGIST. Ug 
 
 delightful landscape views are numerous. The soil is everywhere 
 fertile, but perhaps more especially so along the beautiful valley of 
 the Iowa river, which runs obliquely through the county in the same 
 general direction as the borders of the geological formations before 
 mentioned. The whole region is well watered by springs and 
 streams of constant and remarkably pure water. 
 
 Timber enough for the use of the present and prospective inhab- 
 itants is found in the groves, and in large bodies skirting the streams. 
 Thus there is no real element of prosperity wanting to make Mar- 
 shall county one of the most prosperous in the State. 
 
 FRANKLIN COUNTY. 
 
 Although it was expected from the first that this county would be 
 found to contain peat, yet it was thought best not to devote time 
 enough at present to the full examination of it, but to go to the 
 more northern counties and return to this if time should permit. — 
 From some knowledge of the general character of the surface, and 
 from information since received, it is believed that large quantities 
 of peat exist in the north-western and south-western parts of the 
 county. 
 
 The first peat observed in the county was in the northern part of 
 township ninety, range nineteen, a little north of the farms of 
 Messrs. Smith and Hedge. It is found in a grassy slough, is from 
 two to four feet deep, and probably covers two or three acres. The 
 peat here is not of the best quality, but will make a desirable fuel 
 when thoroughly dried. About half a mile north of this locality, in 
 another slough, a real mossy peat bog of limited extent is to be seen. 
 It occupies about an acre, and is somewhat peculiar in its accumula- 
 tion, for it is raised in a slightly mound - like form above the surface 
 of the surrounding parts of the slough in which it is located, so that 
 it can all be easily drained. A spring evidently comes out here 
 which afi'ords constant moisture for the growth of the moss that 
 forms the peat. This is a good clear article of peat, free from 
 earthy matter, and is known to be more than seven feet deep in the 
 center, but thins out toward the edges. 
 
 A small marsh, containing two or three acres, was seen in the 
 southeastern part of township ninety - one, range twenty. It is 
 
120 
 
 KEPORT OF STATE GEOLOGIST. 
 
 covered with grass, but the usual moss is seen to thickly cover over 
 the surface at the roots of the grass. 'The peat reaches about three 
 feet in depth, and will make a very fair fuel. 
 
 Another marsh was found on section twenty - five, township ninety- 
 two, range twenty, two miles east of Hampton, the county - seat of 
 Franklin county. It is estimated to contain twenty acres of peat 
 which will average two and a half feet in depth. Although these, and 
 other marshes of this county will doubtless furnish large quantities 
 of valuable fuel, it can not be too strongly urged upon the inhabitants 
 to plant largely of our forest trees, for there is no danger that any 
 of them will not grow to be excellent timber, nor any danger that 
 the supply will ever be too great. 
 
 Aside from the comparatively insignificant portion of the surface 
 occupied by the marshes, there is hardly an acre in the whole county 
 which will not produce a good crop of all kinds, for the farm ; and a 
 crop of trees, although slower in bringing a return, will eventually be 
 found to be as profitable and certain as any other. Beside the 
 certainty of pecuniary reward for the labor and money thus expended, 
 there is the consideration of a duty which those owe, who are able to 
 perform it, to provide this indispensable material for their children's 
 use, and also for their own, in the chilling winters of their old age. 
 
 Let those theorize who will, concerning the origin of the prairies, 
 but every day's observation in the whole State from south to north, 
 and from east to west convinces me that there is nothing more 
 certain than the growth of all kinds of our native trees upon prairie 
 soil, and their rapid encroachment upon the prairies without further 
 aid from man than keeping out the annual fires. 
 
 Extended observation has also convinced me of the fact that there 
 is now more timber growing in Iowa than there was twenty - five 
 years ago. 
 
 The immediate surface of this county is underlaid in the southern 
 parts by rocks of sub - carboniferous age, and in the central and north- 
 western parts, by rocks of Devonian age, consequently the whole 
 county is beyond the limits of the coal - field. It is well watered, 
 and the streams and springs are beautifully clear. There is a 
 sufificient supply of stone for all ordinary purposes of building, and 
 the manufacture of excellent lime. The surface is nearly all beautiful 
 
REPORT OF STATE GEOLOGIST. 121 
 
 aud fertile rolling prairie ; the groves, and strips of timber along the 
 streams afford sufficient fuel and fenciog for the use of the present 
 inhabitants, the only deficiency being the want of a full supply of this 
 material to meet the demands of the prospective population of a 
 region otherwise so inviting. 
 
 PEAT. 
 
 It "was intended that extensive examinations of the northern part 
 of the State should be made in the search for peat in the autumn of 
 1866. and in September of that year a brief article was published 
 by me in several of the newspapers of the State, calling attention to 
 the fact, and stating at the same time the reasons which induced the 
 belief that peat would be found there. The substance of that article 
 is repeated in the following, because there are so many of our 
 citizens who are unacquainted with that fuel. It may be that the 
 following description of the conditions under which peat is found, 
 will not fully, answer for all the deposits that maybe discovered in 
 the State, for these descriptions were drawn from observations made 
 principally in the counties of Franklin, Wright, Cerro Gordo, 
 Hancock, Winnebago, Worth and Kossuth. 
 
 Peat had its origin in the partial decomposition of vegetable 
 matter under water, or in a condition of gteat moisture on, or near 
 ths site of its growth. Ii some parts of the world, having a moist 
 atmosphere, it is tound occupying elevated positions ; but in our 
 State it may usually be looked tor in low marshes, most of which 
 have doubtless once been ponds. Wherever a pond has existed, 
 ra'nk grasses, rushes and other plants, have grown upon its borders, 
 and the frosts of each returning Novemb'i'r laid them beneath its 
 surface, their comminuted fragments narrowing the area and lessen- 
 ing the depth of its waters until the surface become the proper 
 habita of a peculiar moss which continues to flourish upon the 
 rapidly - decomposing bodies of the parent stems without a proper 
 root, and which, with the remains of the grasses and other plants 
 that grew with it, has filled some of them with the carbonaceous 
 matter thus produced. A few of these ponds we find only partially 
 so filled, a large margin of peat marsh surrounding the open water 
 in the middle. 
 16 
 
222 REPORT OF STATE GEOLOGIST. 
 
 Again, upon the gentle slopes of some valleys, a belt of springy- 
 land often exists, where the water constantly oozes oat along a 
 considerable distance, and is not gathered into a definite spring 
 stream. Under such conditions the necessary constant supply of 
 water will be furnished for the growth of the moss and other plants, 
 the remains of which form the peat. In such cases the accumulation 
 of peat is not in the bottom of the valley, but upon its slope, 
 commencing just where the water begins to issue. But in a country 
 so dry as ours, we can seldom expect to find peat where there have 
 been no ponds, and consequently it is not to be expected in the well- 
 drained regions of our State in large quantities. 
 
 At the close of that period in our earth's history known among 
 geologists as the glacial epoch, when the continents which now exist 
 had already assumed their present dimensions and shapes, that por- 
 tion of the surface in which our State is situated was much more 
 uniform than it now is. Shallow depressions only existed then, and 
 these save initial direction to the courses of the streams into which 
 the surface waters were gathered. 
 
 The rains, floods and frosts of the unnumbered years that have 
 passed since then, together with the steady flow of the streams, have 
 worn iheir channels deeper and deeper, causing the deepening also 
 of their tributaries as well as the small ravines which lead into them. 
 Thus wherever the streams are numerous, and their valleys deep, the 
 country is perfectly drained ; and consequently few or no ponds are 
 found. But m a region where streams have their rise the depressions 
 will, for a part of the year at least, be filled with water, because 
 there is no accumulation of water beyond to send a current across 
 them to cut a channel for their outlet. In the northern portion of 
 Iowa the streams are numerous, and the region consequently well 
 drained ; but many of those streams having their rise in the northern 
 part ot the State, the physical conditions exist there which are neces- 
 sary to the formation of peat. It must not however be understood 
 that peat does not exist elsewhere, for it is well known that many 
 excellent deposits are found, even as far south as the center of the 
 State ; yet the northern portions may be regarded as pre - eminently 
 its peat regions. 
 
 The general surface occupied by the counties before named is of a 
 
REPORT OF STATE GEOLOGIST. 123 
 
 more or less undulatory character, and although not possessing very 
 strongly marked features, its prairies seldom present that well defined 
 ocean- like horizon -which one frequently observes upon the prairies 
 further to the southward. A very large proportion of the surface is 
 prairie ; that is, it is covered with the usual prairie grasses and 
 plants ; and being largely destitute of trees, it presents to the eye a 
 great many slight, irregular, rounded elevations associated with cor- 
 responding depressions. Some of these depressions are occupied by 
 ponds and lakes because tliey do not communicate with each other so 
 freely as the depressions do in well - drained regions ; and a part of 
 these ponds and lakes have become changed into peat marshes. Why 
 they have not all become so changed is not known, but there are a 
 few ponds and small lakes in this region which show little or no ten- 
 dency to the formation of peat, even along their shallower borders. 
 A range of these peatless lakelets, comprising a quite a number, 
 exists along the " divide " between the Iowa and Boone rivers in the 
 counties of Hancock and Wright. 
 
 They vary from half a mile to a mile and a half across, to some 
 of which the settlers have applied appropriate^names and some have 
 none. Indian names are sometimes beautiful and perhaps appropri- 
 ate, if we new their real signification, but Indian names are not 
 popular among those who have so lively a recollection of the 
 atrocities of Inkpadutah and his murderous band, and who have 
 lived so near the scenes of their carnage. It is, therefore, thought 
 not inappropriate to apply the personal names of Iowa's fair daught- 
 ers to these beautiful lakelets. Thus Lake Cornelia will be found to 
 lie principally in section sixteen, township ninety - two, range 
 twenty four. Lake Flora is near the southeast corner of township 
 ninety - four, range twenty - five, and Lake Mary is within ,a quarter 
 of a mile to the eastward of it. The two last named, have been 
 called Twin lakes, but this is an appellation given in a number of 
 instances, in the northern part of the State, to lakes which happen 
 to lie near each other. Lake Gertrude is about three miles west of 
 Belmond, lying principally in section twenty- eight, township ninety- 
 three, range twenty -four. 'Close to the border of the latter lake is 
 a small pond which lies five or six feet below its level, and well 
 
124: REPORT OF STATE GEOLOGIST. 
 
 illustrates the relation which the peat marshes are sometimes found 
 holding to each other. 
 
 The streams of this region have not those well - defined bottom 
 lands which are so characteristic of the majority of the streams of 
 Iowa, but there is generally a gentle and almost imperceptable 
 descent from the higher lands between them, so that one can not say 
 where the highland begins and the bottom ends. The whole surface, 
 from near the streams to the low dividing ridges, is undulatory, so 
 that the appearance of the descent is sometimes obscured. Thus 
 the peat marshes are as numerous among the low knobs of the 
 " divides " as they are nearer to the streams. 
 
 As before said the common prairie grasses and plants cover the 
 general surface, but usually as soon as the border of the peat marsh 
 is reached, there is a sudden and almost entire change of vegetation. 
 The peat vegetation may be said to consist of a single species of moss 
 and another of a peculiar grass. While other plants may, and do 
 often grow upon, and enter into the composition of peat ; mineral 
 impurities, such as common soil and sand, which form the natural 
 habitat of those plants, may, from this circumstance, be expected to 
 have been diffused in the peat through the agency of floods, high 
 winds, etc.; because these mineral constituents of soil seem to be 
 indispensable to the growth of these plants, while they do not seem to 
 be necessary to the growth of the moss and wire - grass. The peat of 
 marshes near the banks of streams is subject to such impurities, 
 while that of those marshes which are so situated that they can 
 receive no washings from the surrounding surface, is found compara- 
 tively pure. Such marshes are covered almost exclusively, with the 
 two species of vegetation just mentioned. Thus a very correct 
 judgmenc may often be formed of the character of a marsh, by 
 seeing its vegetation, without going upon it. It has been noticed 
 that where the scouring rush grows profusely among the real peat, 
 vegetation, we do not usually find the peat very thick, nor very 
 pure ; yet none of the marshes are entirely free from this rush. 
 
 As we stand upon the higher land and look over one of these 
 marshes, almost the only vegetation growing upon it which meets 
 the eye is the peculiar grass before referred to, known among the 
 inhabit3,nts as wire- grass. 
 
REPORT OF STATE GEOLOGIST. 125 
 
 No specimen of this grass was found in flower or seed, but it is 
 seen that it increases and renews its growth by lateral budding near 
 the roots. These roots form a somewhat loose but very tough sod 
 upon the surface. The leaves are long, slender, somewhat rounded 
 and cellular. Being of nearly uniform length — two or three feet — 
 the level marsh, stretching sometimes more than a mile away, presents 
 much the appearance of a lake, as the wind blows over the waving 
 grass. This is the general appearance of the peat marshes, but 
 there are some marshes presenting this general appearance which 
 contain little or no peat, although its formation there is probably 
 in progress. These are generally small and consequently shallow. 
 Considering the undulatory character of the surface before men- 
 tioned, it would be expected that the smaller marshes would be 
 shallow, but this would of course depend in a great degree upon 
 the abruptness of the undulations. Again, there are very broad 
 marshes in a comparatively flat region, the peat of. which, for obvious 
 reasons, is quite shallow. 
 
 Those marshes which lie upon the more undulating surfaces are 
 frequently arranged in series, each successively occupying a little 
 lower level than the other, and not far apart, like the pond before 
 mentioned near Lake Gertrude. In such cases the marshes may be 
 easily drained from one to another, and finally into the brooklets to 
 which they give rise. 
 
 Approaching the marsh, we find in most cases, as soon as we reach 
 th(! moist ground in the vicinity of its border, the presence of grow- 
 ing moss among the ordinary prairie grass and plants. The moss 
 increases in quantity as the surface becomes more moist, and upon 
 reaching the peat surface we usually find it covered with a thick, 
 soft carpet of moss at the roots of the wire - grass. As we walk 
 upon the surface, if the peat is of any considerable depth, we per- 
 ceive it quaking beneath us, producing the feeling of danger that 
 we may slip through the loose but tough sod into the soft material 
 below. Cutting through this sod with a sharp spade, and lifting out 
 a piece as deep as the spade -blade, we find it a thickly interwoven 
 mass of moss and grass roots in different stages of decomposition, 
 which increases with the depth, so that the lower portion of it may 
 be easily pulled to pieces with the fingers. This, and all between it 
 
12Q KEPORT OF STATE GEOLOGIST. 
 
 and the earthy muck at the bottom, is peat, yet the sod itself, when 
 dry, will make a good light fuel. 
 
 Peat, in various parts of the world, differs much in quality — from 
 a fibrous mass, almost as light as sponge, to a smooth, homogeneous 
 substance, almost as dense, when dried, as coal. Our Iowa peat par- 
 takes of the fibrous character, but is not of tho lightest varieties. 
 It varies considerably in quality, or perhaps more properly speak- 
 ing, in ripeness, by which is meant the more or less complete 
 destruction of the vegetable texture in which it had its origin as 
 a top sod, and which has been left beneath to perfect its peculiar 
 decomposition, by the accumulating growth above. Thus when we 
 bring up specimens from various depths we find that the deeper ones 
 will usually-dry into a more compact mass than the others. This is 
 consequently a better fuel ; not that it will burn any more perfectly, 
 but being more compact it is more durable and capable of producing 
 a more intense heat. Peat in the marsh holds within its substance 
 almost an incredible amount of water, and where it is of considerable 
 depth it quickly absorbs the rain which falls upon it, the surface 
 rising and falling to a limited degree as the moisture dries out by 
 evaporation, or is supplied by the rains ; consequently the surfaces 
 of the deeper marshes have no water standing upon them during the 
 greater part of the year, even when communicating with the open 
 water of an adjoining pond. 
 
 The citizens of Iowa are so universally acquainted with the numbers 
 used in the government land surveys that no explanation is deemed 
 necessary to a list of localities presented in that form. Indeed it is 
 the only method by which localities in such a region could be defi- 
 nitely indicated. The marshes indicated in the list were all visited 
 and tested by myself in pei'son, but for the numbers indicating them 
 I am indebted chiefly to the principal inhabitants, who are well 
 acquainted with the land surveys, and many of whom accompanied me 
 in the examinations. They indicate that the marsh lies wholly or 
 principally upon the sections whose numbers aj-e given, and are doubt- 
 less in the main correct. The number of acres given in the table was 
 estimated, not measured, but an effort was always made to be quite 
 within the limits of truth. The depth mentioned, is the greatest depth 
 ascertained. Most of those indicated as six feet are doubtless deeper, 
 for that was the length of the probe handle used, and when a greater 
 depth was reached, a hole was dug with a spade in which to work the 
 probe. Towards the borders of the marshes the depth was of course 
 
REPORT OF STATE GEOLOGIST. 
 
 127 
 
 always less than that indicated in the list, but the borders having less 
 than two feet of peat were always excluded from the estimates. 
 
 NAME OF COUKTT. 
 
 
 
 Q- 
 
 
 CO 
 
 
 
 
 
 
 
 
 ,13 
 
 
 fc- 
 
 
 C 
 
 
 
 
 ■s 
 
 o 
 
 n 
 ft 
 
 < 
 
 
 
 
 
 rf 
 
 
 
 
 O 
 
 :s 
 
 rn 
 
 ^ 
 
 Ics 
 
 ^ 
 
 fin 
 
 CERRO GORDO 
 
 WORTH. 
 
 •WINNEBAGO. ..-{ 
 
 HANCOCK. 
 
 WRIGHT 
 
 KOSSUTH I 
 
 34 
 
 3 
 11 
 13 
 ( 13 
 14 
 14 
 15 
 35 
 36 
 
 2 
 
 5 
 
 23 
 25 
 26 
 33 
 
 8 
 37 
 
 li 
 
 34 
 
 13 
 
 2 
 
 34 
 
 19 
 
 7 
 
 rl4 
 
 15 
 
 37 
 
 (37 
 
 (38 
 
 5 
 
 5 
 
 35 
 
 f30 
 
 J 21 
 
 1 28 
 
 [39 
 
 (19 
 
 (30 
 
 1 
 
 10 
 
 3 
 
 1 
 
 9 
 
 4 
 
 16 
 
 86 
 
 11 
 
 4 
 
 35 
 
 16 
 
 21 
 
 31 
 
 1 
 
 38 
 
 16 
 
 97 31 
 
 97 
 97 
 97 
 97 
 
 97 32 
 
 97i33 
 
 96 '32 
 
 97'20 
 
 96119 
 
 97 1 20 
 
 100130 
 
 100 30 
 
 100:20 
 
 100!20 
 
 99 20 
 
 99 
 99 
 99 
 99 
 
 99 33 
 
 99 23 
 
 99 23 
 
 99 23 
 
 100122 
 
 100 23 
 
 IO0I23 
 
 100,32 
 
 98 33 
 
 98 33 
 
 100 34 
 
 IOOI24 
 
 100124 
 
 100 24 
 
 98 23 
 
 98 23 
 
 97 25 
 
 97>4 
 
 97 23 
 
 95 24 
 
 95 24 
 
 95 24 
 
 95 1 24 
 
 96|25 
 
 94 24 
 94I34 
 93 34 
 90 34 
 90 24 
 90 33 
 
 95 29 
 97 28 
 9629 
 
 200 6 
 
 )■ 100 
 
 I 200 
 
 125 
 
 150 
 
 100 
 
 50 
 
 [ 250 
 
 50 
 
 150 
 40 
 
 ( ,= 
 
 20 
 40 
 40 
 
 I 450 
 
 40 
 
 I 100 
 
 300 
 
 j- 300 
 
 40 
 
 50 
 
 100 
 
 1 
 
 1-1000 
 I 
 
 J 
 
 [1000 
 
 500 
 60 
 50 
 80 
 
 [ 500 
 
 150 
 100 
 100 
 150 
 
 j- 250 
 
 50 
 
 40 
 
 200 
 
 100 
 
128 HEPORT OF STATE GEOLOGIST. 
 
 The foregoing list of marshes is intended by no means to be a 
 complete one for the region named, the principal object being to call 
 public attention to the fact of the existence of large quantities of 
 valuable fuel which have thus far been overlooked. All the ma,rshe3 
 known to exist in this region were not visited, and many were seen 
 that are larger than some of those here enumerated. Besides these, 
 small marshes containing from ten to thirty acres each, with from 
 two to four feet of peat, are very numerous. These arOynot included 
 at all, although they will be capable of supplying the persons who 
 own them with all necessary fuel within their own means. Other 
 beds, again, it will be seen, are so large that they will supply 
 material for the most extensive machinery, as soon as the demand 
 will warrant it. Residents of this region have estimated, and 
 perhaps correctly, that the counties of Cerro Gordo, Hancock, 
 Worth and Winnebago, contain four thousand acres each of good , 
 peat lands. Certain it is that the supply is so abundant, and so 
 generally distributed, that it will be very difficult for capitalists to 
 obtain a monopoly of it. Kossuth county has been only partially 
 examined, but it is known to contain some very fine marshes, and it 
 is expected that its northern part will be found to contain many 
 more. 
 
 In other parts of the world we learn that peat is found having a 
 depth of thirty or forty feet; but we have as yet no reason to expect 
 the discovery of any such beds in Iowa. In the region under 
 discussion, the character of the surface, as before described, forbids 
 it ; the inequalities are too gentle to leave depressions of that depth 
 which might become filled with peat. The majority of the marshes 
 • have probably less than six feet of peat at their greatest depth ; yet 
 some are already known to be more than eight feet deep. 
 
 So little is known by those who live in the West concerning the 
 use of peat, that many questions which naturally arise, can not at 
 present be answered. From the fact that much is said about the 
 manufacture of peat, and that many machines are offered in the 
 market, those who find themselves the owners of peat marshes 
 earnestly ask the question : " Is it indispensable that- peat must 
 pass through a process of manufacture before it can be burned ? If 
 so, it is necessary that a capitalist with |5,000 or $10,000 should 
 
JIEPORT OF STA.TE GEOLOGIST. 129 
 
 stand between us and a supply of fuel from our own lands ; or may 
 we not prepare a good article within our limited means ? " 
 
 These are important questions and will be answered as clearly as 
 possible, It is not indispensable that peat should be manufactured 
 before it is burned, for it has been used in the crude state for hun- 
 dreds of years. Drain the marsh by cutting one or more ditches 
 clear through it, communicating with the outlet, and put a gate at 
 the outlet that you may protect it from the annual prairie fires by 
 flooding it. Wh^n well drained, strip off the sod with a very sharp 
 spade. Then with the same spade, or better still, with an Irish 
 slane, cut the peat into convenient blocks, dry them on the ground, 
 and store them in a dry place for use. The slane is an instrument 
 something like a spade with the blade, which is of thin steel, about 
 sixteen inches long and ten inches wide, bent at right angles like a 
 'carpenter's corner - chisel, so that the two sides will cut the width 
 and thickness of the peat block at the same thrust. 
 
 This is the simplest method of its preparation, but the same peat 
 which thus prepared will answer in a satisfactory manner all the 
 purposes of ordinary fuel, can be rendered a very superior article, 
 both for doipestic and manufacturing purposes, by a condensing pro- 
 cess of manufacture. The advantages gained by manufacture are 
 the reduction of bulk, so as to require less storage room, and the in- 
 crease of density enables us to produce a hotter fire within a small 
 space. 
 
 Machines have been constructed for compressing peat into blocks 
 when partially dried, and, although the fuel is much improved 
 thereby, it has been found that the compressed blocks quickly disin- 
 tegrate by absorption of moisture from the atmosphere, and by hand- 
 ling, so as to render it inconvenient and troublesome. It is now 
 generally conceded that a condensing, and not a compressing process, 
 is the proper one to be adopted in the manufacture of peat ; and 
 this view is without doubt the correct one. The condensing process 
 consists in grinding the peat while wet, in a properly constructed 
 mill, into a smooth pulp, which is then moulded into convenient 
 blocks, without great pressure, and dried for use. While these 
 blocks are drying, the cellular spaces which existed between the 
 fibres of the crude peat, being broken up by the grinding process, 
 
 IT : .. 
 
J 30 REPORT OF STATE GEOLOGIST. 
 
 they shrink into a compact mass, quite unlike the light, crude peat 
 from which it was manufactured. When thoroughly ground and 
 prepared in this manner, it shrinks by the natural process of drying 
 alone, into denser masses than blocks of the same peat would be 
 when dry, after having been compressed by the most powerful 
 machinery, without previous grinding, when, of course, the violent 
 compression would be useless. 
 
 No data have been obtained by which to estimate the difference in 
 value between the well - manufactured and crude peat, but, judging 
 from specimens in my possession, it is certainly as great as that be- 
 tween bass - wood and good hickory. 
 
 Well - dried hickory is probably the best fire - wood in use, but, 
 from the fact that it will float upon water, while pure, dry, well- 
 manufactured peat will sink in it, it is evident that the latter con- 
 tains the greatest amount of combustible matter, bulk for bulk. 
 
 There is no doubt of the value of the large condensing machines, 
 such as Leavitt's and others, for those who wish to establish a busi- 
 ness for the manufacture and sale of peat, but a great desideratum 
 IS a small machine which will come within the means of every family 
 in the peat regions, so that they may prepare their own fuel by their 
 own labor. Peat being much improved in quality, even by an im- 
 perfect grinding, it is not improbable that small machines may soon 
 be introduced that will produce an excellent article of domestic fuel, 
 in a more convenient form than it usually is when taken from the 
 marsh without preparation. 
 
 Upon comparing Samples of Iowa peat with my specimens from 
 Ireland, and from various parts of our own country, no doubt is 
 entertained that ours is all of excellent quality, nOr that it will sooii 
 become invaluable in the settlement of the region where it is found. 
 Estimates have been made as to the value of peat compared with 
 wood and coal. According to some of these estimates a ton of well 
 dried, compact peat is equal in heating power to a cord of hickory 
 wood, but as far as the greater part of the Iowa peat region is 
 concerned, it is perhaps, sufficient to say that the results have not 
 been disparaging to peat, but such estimates are not at all necessary 
 in this case, for the real peat region lies wholly beyond the limits of 
 
 ( { 
 
REPOET OF STATE GEOLOGIST. X31 
 
 the coal - field, and the timber although enough for the present inhab- 
 itants, can not supply a tithe of^the fuel which the prospective 
 population of a region so fertile and inviting, will soon demand. 
 Peat has there a local value which can never be questioned. 
 
 Peat may be burned in ordinary fire - places, grates and stoves, 
 but appliances, peculiarly constructed for its use, will doubtless be 
 found in the market as soon it is generally known that there is a 
 demand for them, and experience as to the best methods of its use 
 will be gradually acquired. Messrs. Mumford & Bmsley of Mason' 
 City, are making great efi'orts to introduce the use of peat among 
 the inhabitants of their neighborhood and have just started a small 
 mill for its manufacture at that place. These gentleman have 
 resolutely overcome many difficulties, and the supervisors of Cerro 
 Grordo county have very commendably encouraged them by giving 
 them a favorable contract for furnishing the county offices with fuel. 
 
 The amount of fuel which the marshes of this region may be 
 made to produce is immense ; and yet they are not sufficiently 
 numerous to be a reproach, as they are in some parts of Ireland ; 
 nor of such a character as to be an unsightly blemish upon its fair 
 and fruitful surface. 
 
 The following data are believed to be reliable as to the amount of 
 peat to be obtained from a given number of acres, and of its value 
 as fuel ; 
 
 Two hundred and fifty tons of dry fuel per acre of well - drained 
 marsh for every foot in depth ; the marsh being estimated to settle 
 from one quarter to one third of its original depth by draining. 
 
 Thus we may estimate upon the annual allowance of thirty tons 
 of peat to each family, that one hundred and sixty acres of peat, 
 four feet deep will supply two hundred and thirteen families with 
 fuel upward of twenty -five years. , 
 
 Knowing the rapidity with which our forest trees will grow upon 
 our soil, this would give ample time to grow a supply of fuel to be 
 used when the peat should become exhausted. 
 
 Having necessarily been familiar with the few diseases prevalent 
 in Iowa, I took particular care while in the region of peat marshes 
 to make inquiries and observations concerning the health of the 
 
132 REPORT OF STATE GEOLOGIST. 
 
 people who live there. The time occupied by my examinations was, 
 that portion of the year, when malarial diseases prevail (if they 
 ever do) ; but I did not see or hear of a single case of those diseases 
 nor of any other. The presence of the peat marshes is evidently in 
 no way prejudicial to health, from the fact that the profuse vegeta- 
 tion does not reach a complete state of decomposition, the resulting 
 peat being itself antiseptic in its properties. 
 
 After the examinations referred to in the foregoing pages were 
 made, three important marshes in the central parts of the State were 
 visited, beside one in Whiteside county, Illinois. It has been ob- 
 served in the northern part of the State that those marshes whose 
 vegetation is almost exclusively wire - grass and moss contained the 
 purest peat, and that those which contained a greater proportion of 
 foreign matter had a mixed vegetation growing upon them. These 
 marshes in the central parts of the State all have a somewhat mixed 
 vegetation, yet the peat is usually very pure. Whatever may be the 
 character of the more conspicuous vegetation, the moss is always 
 present upon all marshes, and always enters largely into the compo- 
 sition of the peat. 
 
 Peat has been manufactured from all but one of these during the 
 past season, and from these sources some very encouraging data were 
 ■obtained concerning its manufacture and the great favor with which 
 it is received as a fuel by those who have tried it. 
 
 The first marsh visited is situated in Muscatine county, principally 
 lupon section fifteen, township seventy -seven, range four, eight miles 
 south of West Liberty, and about twelve miles from Muscatine. It 
 ■contains about one hundred and fifty acres of peat, and the depth is 
 reported to reach thirteen feet in some places. This marsh is on the 
 line of the Burlington & Cedar Rapids Railroad, three - quarters of 
 a mile from the right bank of Cedar River, and occupies an ancient 
 ibed of that river which was deserted as it cut its channel deeper, so 
 as to leave a pond there which is now beyond its highest floods. 
 This pond, supplied with a large part of the necessary moisture by 
 ;sprmgs which ooze out from the base of a sandy bluff about twenty 
 feet high which partly encircles the marsh, has become filled with 
 peat. 
 
REPORT OF STA.TB GEOLOGIST. J 33 
 
 The reason why other similar depressions left by the receding river 
 have not become so filled, may perhaps be found in the fact that they 
 do not possess th^e surroundings that this one does, namely : stretch- 
 ing away from the low bluff which borders the marsh is a level tract 
 of land which is itself bordered on the west by another low ridge 
 having the general direction of the course of the river. Along the 
 base of this ridge is marshy ground, but it is not a peat marsh, 
 although it doubtless occupies a still more ancient bed of the same 
 river. Between these two marshes the soil and subsoil is sandv, so 
 that the water which falls upon the level tract quickly percolates 
 through to the peat marsh or to the river. The peat of this marsh 
 is good, and it will be of great value to the region where it is located. 
 
 The next marsh visited contains about thirty acres, and is situated 
 on section eleven, township eighty - three, range six, about four miles 
 west of Marion, Linn County. It is reported to reach ten jjeet in 
 thickness, but where it is now worked, it is about five feet deep of 
 drained peat. Mr. Hoffman and Mr. Cougill are the owners of the 
 land, but Messrs. Traer and. Bundy have leased it, and have com- 
 menced manufacturing the peat for market, using a machine which is 
 an invention of the last - named gentleman. It was not in operation 
 at the time of my visit, but some very good specimens of the peat 
 prepared by it were obtained for the State collections. This is one 
 of the best examples of a " spring marsh " yet seen. It lies wholly 
 upon the gentle slope bordering one of the upper branches of a 
 tributary of Cedar River, hardly reaching the branch itself. It is 
 fed with moisture by springs which issue along this slope, while 
 upon the opposite one there is little or no peat, doubtless because 
 few or no springs exist there. The deposit is so rounded in its 
 central portions that in general aspect it has very much the appear- 
 ance of one of the ordinary elevations of the undulating surface of 
 that vicinity. The marsh has been easily drained by cutting a ditch 
 from its upper to its lower border, in which pure water flows, a 
 perpetual spring. The above-named firm are producing a good 
 article of fuel, and will no doubt be able to supply the demand next 
 year. 
 
 Another marsh, containing about two hundred and fifty acres, two 
 hundred acres of which contains peat of good workable depth, is 
 
134 REPORT OF STATE GEOLOGIST, 
 
 found in Clinton County, upon section twenty -nine, township 
 eighty - one, range two, about two and a half miles south of Calamus 
 station on the Northwestern Railway. A dense fog prevailed 
 during the whole day this marsh was visited, so that the surrounding 
 features of the country could not be seen, but there are some indi- 
 cations that it was formerly a pond. The subsoil of the region 
 around it, however, being sandy, it is quite probable that it has 
 derived its moisture largely from springs. 
 
 A firm have established machinery here for the manufacture of 
 peat, but the season closed before they were fairly able to introduce 
 the fuel to the market. Mr. Isaac Heald, of West Liberty, one of 
 the proprietors, informs me that they expect to prosecute the busi- 
 ness energetically as soon as the spring Opens. 
 
 In Illinois, about seven miles eastward from Clinton, there is a 
 very large peat -marsh where two or three machines have been in 
 effective operation during the past season. At this marsh an oppor- 
 tunity was had to see some very satisfactory results of the manufac- 
 ture, although none of the machines were in operation. The blocks 
 of peat manufactured here are almost as dense as coal, and Mr. 
 Dodge, one of the proprietors, informs me that he has not been able 
 to supply the demand which already exists for it at seven dollars per 
 ton. He also tells me that the cost of manufacture does not exceed 
 two dollars per ton. Here is a profit, then, which ought to satisfy 
 any one. 
 
 A ton of prepared peat being equal in value to a cord of hickory 
 wood, and the latter averaging throughout the State, after being 
 prepared for the stove, at least six dollars per cord, it is easy to see 
 that peat will be valuable anywhere. But this is not the only way 
 to estimate the value of peat to the northern part of the State. 
 For instance, if by some possible disaster all the forest trees of a 
 region dependent upon that source alone for fuel, should be swept 
 out of existence. The loss would not be the market value alone of 
 the fuel destroyed, but that loss would greatly lessen the value of all 
 the other property of the region thus affected. The converse of this 
 is also true; a region possessing all other elements of wealth, but 
 heretofore supposed to lack one essential element, receives additional 
 
REPOET OF STATE GEOLOGIST. 135 
 
 value by the discovery of that element. The assurance that a suffi- 
 cient amount of fuel exists in those almost treeless but fertile 
 regions of Northern Iowa, will cause its settlement nearly a genera- 
 tion before it otherwise would be. 
 
 GYPSUM. 
 
 Although gypsum has been known to exist in the vicinity of Ft. 
 Dodge, in Webster county, for more than twenty years, the public 
 have had very little information concerning it. Information of this 
 kind being desirable to the people of the State, about two weeks of 
 last October were given to the examination of the region by myself 
 and Mr. St. John, upon my return from the peat region further north. 
 Although all the exposures of gypsum are found within an area of 
 six miles in extent, northward and southward, and three miles east- 
 ward and westward, the amount of material is so great that it is 
 practically inexhaustible, and, withal, it is one of the most remarka- 
 ble deposits of this substance yet known. 
 
 The region round about has the general prairie surface so charac- 
 teristic of a large portion of Iowa, but along the Des Moines River 
 and its tributaries there is a good supply of timber covering the 
 valleys and slopes which, with the bold features of the river valleys, 
 give many interesting landscape views, and make Ft. Dodge one of 
 the most pleasantly located towns in the State. The river has eroded 
 its valley here to a depth of more than one hundred and twenty feet 
 from the general prairie level, and it is along its steep bluffs and upon 
 the sides of the creek valleys and ravines which lead into it that the 
 gypsum is found. It is exposed in bold quarry - fronts, having in 
 the distance almost the exact appearance of limestone, and one at 
 first finds it difficult to believe that it is any thing else. At one 
 exposure on the southwest quarter of section thirty - three, township 
 eighty - nine, range twenty - eight, we measured twenty - eight feet in 
 perpendicular thickness of solid gypsum. There is no doubt that it 
 reaches thirty feet in thickness at that place, further into the bluff, 
 and it is believed to be equally thick in other places. The gypsum 
 rests upon shale, which, when exposed to atmospheric influence, 
 softens into clay. Upon this, large masses have slidden down in some 
 
236 REPORT OF STATE GEOLOGIST. 
 
 places from their natural position, increasing the apparent thick- 
 ness of the gypsum deposit, but we saw nothing to convince us that 
 it is anywhere much more than thirty feet thick. The lines of strati- 
 fication are horizontal and well marked, and no doubt is entertained 
 that the formation is continuous horizontally over a great portion of 
 the area, and perhaps further, just as limestone formations are. 
 
 Gypsum in other parts of the world is often found in irregular 
 masses associated with shales and limestone, but here the deposit is 
 one of solid gypsum, not intermixed with layers of shale or any 
 other substance. It is proper to say, however, that all we yet know 
 of this, or other deposits, leads to the belief that ours may not 
 actually extend much beyond the region in which it has been dis- 
 covered. The clearly defined base of the gypsum was several times 
 found, but the top of it is always indefinite in consequence of erosion 
 by water which reaches it from the surface. 
 
 The base of the gypsum deposit being so well defined we were 
 able to clearly ascertain that it rests unconformdbly upon the strata 
 beneath it. In consequence of this unconformability and the fact 
 also that it contains no fossils, we do not know with certainty its 
 geological age ; but it is probably much later than the carboniferous 
 age, since the strata of that age are now well understood in the west, 
 and no true unconformability has been found to occur among them in 
 Iowa, above the sub - carboniferous. Any one paay recognize this 
 unconformability by going down Two -mile creek from the exposure 
 just mentioned where the base of the gypsum is seen resting upon 
 the coal - measure shales. Following down the creek he sees the 
 shales, clays and sandstone, as well as a little coal, exposed at 
 intervals along the creek, and the gypsum above it all in the sides of 
 the hills. Reaching the mouth of the creek and going three - quar-. 
 ters of a mile down the river shore he will find a small exposure of 
 the same limestone formation that is seen in Lizzard and Soldier 
 creeks above town. He will thus have passed down through a 
 vertical thickness amounting to about one hundred feet. Now let 
 him go to Mr. Mitchell's gypsum quarry on Soldier creek, which is 
 about five miles to the northward from the last named locality, and 
 he will find the base of it in such position that it must rest almost, 
 
REPORT OF STATE GEOLOGIST. 137 
 
 if not directly upon the limestone which Mr. Cummins is quarrying 
 for his kilns a few rods distant; showing that although some coal 
 measure shales are exposed on Soldier creek they are wanting at this 
 particular point. This is what is meant by unconformability, and it 
 gives in this case, satisfactory evidence of the want of other forma- 
 tions between the coal - measures and the gypsum. The limestone 
 just mentioned is known by its fossils to be the same as that on 
 Lizzard creek, and also that just mentioneil on'section five, township 
 eighty - eight, range twenty - eight. It is sub-carboniferous limestone, 
 and although not seen in all places along the river and creeks, 
 doubtless underlies the whole region at no great depth. 
 
 The principal exposures of gypsum are three or four miles below 
 Fort Dodge, but some important ones are almost within the city 
 limits. Upon sections six and seven, township eighty- eight, range 
 twenty - eight ; sections one, two and twelve, township eighty - eight, 
 range twenty - nine, and section thirty - three, township eighty - nine, 
 range twenty - eight, they are very extensive and easily accessible. 
 Very important exposures are also found on other sections, all of 
 which have been mapped by us for publication in the final report, 
 and we estimate that following down all the creeks and ravines in the 
 region, limited as it is, one will find not less than seven miles of con- 
 tinuous exposure of gypsum, upon which quarries may be opened 
 anywhere by a day's labor. 
 
 Masses of a few hundred pounds weight of white gypsum, almost 
 chemically pure, have been found associated with that of the main 
 deposit, but so far as observed they seemed to be somewhat concre- 
 tionary in form, and partially detatched from it. The main deposit 
 is of a rather uniform grey color, somewhat in shade like that of a 
 printed page, yet plaster - of- paris prepared from it is nearly white. 
 It has been fully tested at the Geological Rooms, and found inferior 
 to none in quality. 
 
 It may be necessary to state for the benefit of some readers that 
 
 gypsum is a chemical compound of sulphuric acid, lime and water. 
 
 It is much softer than ordinary stone, and when crushed and ground 
 
 to a fine powder in an ordinary grist - mill, it goes by the common 
 
 name of "plaster," in which form it is largely and beneficially used 
 
 as a fertilizer. If this dry powder is placed over the fire in an iron 
 18 
 
138 REPORT OF STATE GEOLOGIST. 
 
 cauldron it boils as if water had been artificially added to it. This 
 is caused by the escape of the water before inentioned, which, when 
 thus chemically combined, although nothing but common water, is 
 just as much a solid as the lime is with which it combines. When 
 the boiling has ceased the powder consists of sulphuric acid and 
 lime alone, in which form it is called " plaster - of- paris," and is 
 used in the arts for stucco work, models, ornaments, statuary, &c. 
 
 When plaster -of- paris has been long kept it absorbs water from 
 the atmosphere, and thus approaches its original condition again. It 
 can be fully restored to its former quality by re - boiling, of course 
 adding no water. 
 
 The reason why objects formed in plaster - of- paris do not shrink 
 in the process of drying, as other substances do when mixed with 
 water, is because a large part of the water used to mix the powder 
 with, enters again into chemical union with it, and is not again evap- 
 orated at ordinary temperatures. 
 
 The principal uses to which gypsum is applied are those just men- 
 tioned, but the people of Fort Dodge have been using it in the place 
 of common stone. Some years ago, Hon. John F. Duncombe built 
 a large, fine residence of it in the city, and he informs me that he 
 is perfectly satisfied with it as a building material. Several other 
 smaller buildings have been built of it, and large slabs which some 
 of the quarries afi'ord make excellent sidewalks, because they do not 
 become slippery as stone walks do. We have no information that 
 gypsum has ever been used as a building stone anywhere else than 
 at Fort Dodge, consequently its citizens are as competent to decide 
 that question as any one, but the following facts are worthy of con- 
 sideration in estimating its value for such purposes. About three 
 parts, by weight, of gypsum are soluble in one thousand parts, by 
 weight, of water. If water which already holds gypsum in solution, 
 rests upon it, it will not be afi"ected thereby, but if it be exposed to 
 the action of running or falling water, it will be rapidly destroyed. 
 This eflfect is often seen where little rills of water caused by the 
 rains, run over the face of an unused quarry, and cut deep grooves 
 into it, sometimes giving it the appearance of melting ice around a 
 waterfall. 
 
 When built into the walls of a house only a small portion of its 
 
REPOKT OF STATE GEOLOGIST. 139 
 
 surface is exposed to occasional rains, the effect of wliich must be 
 very slow, indeed, upon it. This effect can be almost. entirely pre- 
 vented by an occasional coat of linseed oil, which also improves its 
 beauty, as can be seen in Mr. Buncombe's house. Wooden buildings 
 require such protection, and even with it are probably no more 
 durable than those built of gypsum, for those thus far built of the 
 latter material show no signs of failure or decay. With the imme- 
 diate prospect that Fort Dodge now has for railroad communication, 
 her gypsum quarries must become very valuable. 
 
 By rough estimate it is calculated that there is now annually used 
 in our State about seven thousand dollars worth of plaster -of-paris, 
 for mechanical and artistic purposes alone, all of which is brought 
 from other States, and from the province of Nova Scotia ; the near- 
 est of which localities is more distant from our State than Fort 
 Dodge is from the most remote town within it. Should the manufac- 
 ture of plaster be commenced at Fort Dodge, the State of Iowa 
 would not furnish the only market for it, but Minnesota, Nebraska, 
 and parts of Missouri, Illinois and Wisconsin would also find it more 
 convenient to obtain their supplies of this material from Fort Dodge 
 than from any other source. 
 
 This estimate does not include fertihzing plaster, which it is 
 believed will largely benefit even the rich soils of Iowa, for it is 
 doubtful whether the action of plaster upon soil is so much a fer- 
 tilizer, in the common meaning of the term, as an agent effecting the 
 retention of moisture. In either case, it& effects are beneficial. 
 
 Allowing that the gypsum does not extend beneath the greater 
 part of the area before mentioned, as it is believed to do, but that 
 it is no more than fifty feet wide from the face of the exposures, 
 and only twenty instead of thirty feet deep, the following figures 
 show the supply of material that can be obtained from the estimated 
 seven miles of exposure ; 36,960,000 cubic feet of material as quarry 
 rock, or 2,648,800 tons of plaster for fertilizing purposes, or 
 2,092,860 tons of plaster - of- paris for use in the arts. These esti- 
 mates are based upon the following data : Quarry gypsum weighs 
 143J pounds per cubic foot. When this is separated from its water 
 of crystalization by heat, it leaves 113i pounds of plaster - of - paris. 
 These estimates are believed to embrace only a fraction of the 
 
140 REPORT OF STATE GEOLOGIST. 
 
 amount of material which actually exists there, and are only given 
 to call attention to the great importance of that deposit. 
 
 Gypsum is much more easily quarried than stone. Instead of 
 being drilled for blasting, it is bored with an augur as readily as 
 wood, and blocks are dressed into any desired shape with common 
 axes and saws, instead of being done with stone - masons' tools. 
 Thus the labor of preparing it for building purposes is much les8 
 than that required for the preparation of stone for the same uses. 
 
 Salt is so often found in connection with gypsum deposits, that 
 the suggestion often arises whether we may not expect to find it in 
 connection with that deposit at Ft. Dodge. All that can be said 
 upon this point is that no indication of the presence of salt in that 
 region has yet been observed, and that since we are quite well 
 acquainted with the condition and character of the strata which 
 underlie the gypsum, the probabilities that a salt deposit exists 
 there are not encouraging. 
 
 COAL, STONE, &c., AT FT. DODGE. 
 
 The season being so near its close, very little time could be given 
 -to the examination of the coal - measure strata in this vicinity ; but 
 enough was seen to convince us that the Ft. Dodge region, as a coal- 
 producing district, has been much underrated. There is good reason 
 to believe that the coal - field does not extend much to the northward 
 of the city, but there is evidence that up to a point four or five miles 
 below the city there is a very important development of the produc- 
 tive coal - measures. 
 
 A short time was spent in that vicinity, in company with Mr. Dun- 
 combe, visiting the mines and exposures of coal. These are princi- 
 pally along Holladay's creek, and the branches which lead into it, 
 and also into the river. 
 
 We saw evidence of the existence of four different beds of coal 
 here, all lying above the level of the Des Moines River, two of which 
 are very important. One of these beds is known to reach a thickness 
 at one point of nearly five feet. This is now thought to be the highest 
 bed in the series in this vicinity, but we are not fully satisfied upon 
 this point. It is believed to be one of the lower beds that is operated 
 by Hon. Samuel Rees, near the bank of the river, just below town. 
 
REPORT OF STATE GEOLOGIST. 141 
 
 This is evidently not very far above the limestone, and is probably 
 the lowest bed of bituminous coal in the region. Thomas Sargent, 
 Esq., has an exposure of coal at his farm on Lizzard creek, some 
 four miles west of town, which is believed to be identical with the 
 bed of Mr. Rees' mine, and if so there is probably no other coal 
 beneath it, unless it be the bed of impure cannel coal which is seen 
 in the river bank, on section seventeen, township eighty - eight, 
 range twenty - eight, which bed also probably underlies Mr. Rees' 
 mine. 
 
 The sub - carboniferous limestone, before mentioned as occurring at 
 the base of the coal- measures at Ft. Dodge, is known by its fossils 
 and general characters also to belong to the St. Louis division, and 
 is identical with that so often mentioned before as forming the floor 
 (so to speak) of the coal-measures in Marion, Mahaska, Wapello, 
 Van Buren, Jefferson and other counties to the southward, as well as 
 in Hamilton, the next county eastward from Webster. This lime- 
 stone seems to rise and disappear with considerable rapidity to the 
 northward, after its appearance from beneath the river in the vicinity 
 of Ft. Dodge. Mr. Cummins manufactures large quantities of excel- 
 lent lime from it on Soldier creek, just north of town, and both upon 
 this and Lizzard creek much building stone may be obtained. Along 
 the Des Moines river for a distance of a few miles there are also 
 large exposures which thus far have remained almost untouched, be- 
 cause the gypsum is obtained with less labor for the same uses that 
 common stone is usually applied to. 
 
 In some places in the vicinity considerable quantities of the ordi- 
 nary coal -measure sandstone are to be obtained, some of which 
 would make good coarse building material, but much of it is poor. 
 
 In the spring of 1866, a very small deposit, containing a few hun- 
 dred pounds of fine columnar sulphate of strontia was found in the 
 coal - measure strata near Mr. Rees's mine just below town, and at 
 the top of the gypsum on Soldier creek, a small quantity of the same 
 mineral was also found. This is believed to be the first instance of 
 the discovery of that mineral in Iowa. It is true it has very little 
 economic value, except that it is used to produce the red light in 
 fire - works, but it is very interesting to the mineralogist. 
 
2^12 REPORT OF STATE GEOLOGIST. 
 
 BOONSBORO COAL MINES. 
 
 While on the way home at the close of the season a very brief 
 visit was made to the coal mines at Boonsboro. 
 
 These mines are opened at intervals along each side of the valley 
 of Honey creek, which empties into the Des Moines river near 
 Boonsboro and also along the hill sides bordering the river ; all of 
 them opening almost directly upon the Northwestern Railway. Two 
 beds are now being worked here, one of which is a little over three 
 feet, and the other two feet in thickness. These it will be seen, 
 although they furnish large quantities of good coal are not by any 
 means so heavy beds as some others in Iowa ; and yet there are no 
 mines in the State which have a greater present, and perhaps I may 
 add, a greater prospective value, than those of Boonsboro. This 
 arises from their unusually favorable location, affording them a good 
 market at high prices, and also, from the further fact that they are 
 intelligently and extensively worked. A number of the mines are 
 in the hands of private individuals, but far the greater part of the 
 coal land is held, and the coal taken out by two companies, the 
 Northwestern Coal Company and the Moingona Coal Company. 
 The former company, beside the products of its own extensive 
 mining, purchase a great part of the coal taken out by private 
 parties for shipment with their own. Much the greater part of 
 the coal which this company ships, goes to the great Pacific Rail- 
 way, the Northwestern Railway being supplied principally by the 
 Moingona Company. From the fact that these two great lines of 
 railway consume nearly all the coal of this region as fast as it is 
 mined, very little has hitherto been known, by the general public, of 
 the importance of the Boonsboro mines. 
 
 The Northwestern Coal Company are shipping about one hundred 
 tons of coal per day, and this is probably not much more than half 
 of the aggregate amount mined per day in that neighborhood. All 
 the coal is sold as fast as it is raised, and the demand is constantly 
 increasing. The energy with which these mines are worked gives 
 some faint indication of the immense quantities of coal which our 
 mines in other parts of the State will furnish when railroad facilities 
 and other improvements shall have opened a market for it. 
 
MISCELLANEOUS. 
 
 OBSERVATIONS UPON THE DRIFT PHENOMENA OP SOUTH- 
 WESTERN IOWA. 
 
 The following article was first published in the American Journal 
 of Science and 'Arts (Silliman's Journal), for May, 1867: 
 
 In the year 1858, I discovered distinct glacial scratches upon an 
 exposed layer of the Upper Burlington limestone (sub-carboniferous), 
 and made full notes and drawings of the same, which having been 
 unfortunately destroyed by fire within a year afterward, no account 
 of the observations was ever published. No opportunity has since 
 presented itself to verify those observations, but I think I am not 
 mistaken in the recollection that there was but one set of scratches, 
 which were straight, distinct, and rather numerous ; having a direction 
 south, about twenty- two degrees east. This, so far as I am aware, 
 was the first observation of glacial scratches upon rocks in situ in 
 the State of Iowa, although boulders with similar scratches upon 
 them are often seen in various parts of the State. 
 
 During my official labors last season, although considerable atten- 
 tion was given to the drift deposit, no similar traces of glacial, phe- 
 nomena were ever discovered, until I reached the Missouri River in 
 Mills county, where, on section sixteen, township seventy-one, range 
 forty-three, west of the fifth principal meridian, very distinct glacial 
 scratches were found upon limestone of the upper coal. -measures not 
 far from the middle of the series. 
 
 The locality is upon the western abrupt slope of the bluifs which 
 border the bottom land of the Missouri River. The river being dis- 
 tant nearly three miles to the westward, the exact hight of the 
 scratches above it was not definitely ascertained, but it is probably 
 not much less than one hundred feet above the ordinary stage of 
 water. About four feet in thickness of ordinary drift material rested 
 
X44 REPORT OF STATE GEOLOGIST. 
 
 upon the straited surface. This had been partially removed by the 
 quarrymen, exposing the scratches to view. Resting upon this light 
 deposit of drift, and sloping upward to the high lands, are about one 
 hundred and fifty feet of that peculiar lacustrine deposit called by 
 Dr. Owen " siliceous marl," and by Prof. Swallow the " bluff forma- 
 tion," which deeply covers the drift and underlying rocks of this 
 region, except where they have been exposed by fluviatile denuda- 
 tion. 
 
 The boulders and pebbles contained in the drift material of this 
 locality are both granitic and metamorphic. They are well- 
 rounded and worn, and straited faces were observed upon quite a 
 number of them, thus as nearly as possible detecting them in the 
 very act of scoring the rocks in situ. 
 
 The scratches here are in two sets, a coarser and a finer ; those of 
 the latter more numerous than the former, but those of both sets 
 being perfectly parallel with their fellows, distinct and straight. The 
 surface of the rock had been ground level and smooth, removing all 
 unevenness of the natural bedding surface. The directions of the 
 striae were determined by a very good pocket - compass. That of the 
 coarser set (No. 1) was found to be S. 20° B., and that of the finer 
 set (No. 2) S. 51° E. No allowance was made in either case for the 
 variation of the magnetic needle, which the local surveyors calculate 
 at about eleven degrees east of north. 
 
 At an exposure of the same limestone one mile below Omaha, the 
 capital of Nebraska, immediately upon the right bank of the Missouri 
 river, and only some six or eight feet above the ordinary stage of 
 water, other scratches of a similar character were observed. They 
 were found upon the upper surface of a firm layer, which the work- 
 men had exposed and were removing for building purposes. Here, 
 however, there is but one set of scratches, their direction being 
 S. 41° W. (set No. 3), not allowing for variation of the magnetic 
 needle. The surface of the rock is nearly or quite level, but the 
 roughness of the natural bedding surface has not been entirely 
 removed, yet the striae were so distinct that no difficulty was found 
 in ascertaining their true direction. 
 
 The drift at this locality is principally composed of a dark colored, 
 stiff, clayey material, intermixed with sand, gravel and boulders, and 
 
REPORT OF STATE GEOLOGIST. 245 
 
 varies from one foot to eight feet iu thickness. Upon this rests the 
 bluff formation as before described. The face' of the bluff at the 
 locality -where the latter observations were made is nearly at right 
 angles with the direction of the strias. 
 
 Considering that the whole region surrounding these localities, and 
 for a long distance to the northward of them, is an entirely open 
 country ; that the present prominently uneven features of the^region 
 had their origin at a period subsequent to the drift ; and the extreme 
 simplicity and uniformity of the strata over which the glaciers must 
 have moved, the direction of their currents which these scratches 
 apparently indicate seems very remarkable. We not only see at the 
 Mills county locality that the scratches upon one and the same 
 surface prove that two separate currents existed there during some 
 portions of the glacial epoch, having a divergence of thirty - one 
 degrees with each other, but also, only about twenty miles to the 
 northward, we find the evidence that another current moved in a 
 direction which formed an angle of ninety - three degrees with one of 
 those in Mills county. 
 
 Since we see no evidence of the cotemporaneous existence of 
 obstructions which might have deflected the current of a regular 
 southerly - moving glacier, and thus have produced the scratches in 
 the various directions shown, it seems necessary that we should seek 
 for some other explanation of them. Observations thus far made 
 certainly aff'ord very inadequate data upcn which to base a definite 
 theory concerning the real direction of glacial currents over this part 
 of the continent, but the coincidence of the direction of those 
 scratches which have been observed with the general course of the 
 ■draing.ge of the region in which they occur, is worthy of careful 
 consideration. By reference to the mention of the locality, near 
 Burlington, at the commencement of this article, and to a map of 
 Iowa, it will be seen that the direction of the scratches observed there, 
 coincides pretty nearly with the general direction of the drainage of 
 the eastern watershed of the State. 
 
 Set No. 3 represents a current coinciding quite as nearly with the 
 general direction of the drainage upon the western watershed; 
 and sets No. 1 and No. 2 respectively represent currents approxim- 
 ately coinciding with the general courses of the Missouri and Platte 
 19 
 
146 REPORT OF STATE GEOLOGIST. 
 
 Rivers. That the close of the drift epoch left the surface of our 
 State unmarked by strong features, and with shallow, longitudinal 
 depressions which gave initial direction to the courses of the 
 streams, and that these subsequently cut out their own valleys by 
 erosion, there seems to be no reason to doubt. It seems not improb- 
 able, also, that these initial depressions in the surface, whether 
 primarily caused by flexures of the earth's crust, as Whitney has 
 suggested, or not, may be regarded to some extent as ir, dices of the 
 general direction of ancient glacial currents. 
 
 There is another interesting matter in connection with these 
 observations of drift phenomena along the Missouri River, and the 
 existence of the important lacustrine deposit there. The close of 
 the drift epoch evidently left a large depression of the general 
 surface in the region, a portion of which is now occupied in part by 
 the counties of Fremont, Mills, Pottawattamie, Harrison and 
 Monona. This depression became a large fresh -water lake, the 
 borders of which have not yet been definitely ascertained, but no 
 satisfactory evidence of its existence eastward of the East Nishna- 
 botany River has been observed in Iowa. The Missouri River 
 evidently emptied into this lake, and flowed from it, until it became 
 filled with the peculiar deposit of fine, siliceous, marly material, 
 known as the blufi" formation, the character of which is very much 
 the same as that of the muddy material which would now be depos- 
 ited from the waters of the river if it were possible to throw a 
 permanent obstruction across it. As the valley of the river was 
 gradually deepened during the Terrace epoch, its waters found no 
 difficulty in sweeping out the fine homogeneous material which they 
 had before deposited, leaving those high peculiar blufi"s upon each 
 side of its broad bottom. Fresh - water and land shells of existing 
 species, principally Gasteropods, are often found in this deppsitj 
 from base to top, and its thickness sometimes reaches more than two 
 hundred feet above the drift material upon which it rests. 
 
 Seventy or eighty miles to the eastward of the Missouri River, in 
 the southern tier of counties, there are evidences that the drift 
 deposit reaches a thickness of more than a hundred and fifty feet. 
 Westward from that region a sensible diminution of its thickness is 
 seen, and, reaching the region of the bluff formation along the 
 
REPORT OP STATE GEOLOGIST. 147 
 
 Missouri river, the drift material is found in all cases comparatively 
 thin, being thinnest where the blufif material is thickest. 
 
 At the localities where the scratches were observed, the drift 
 material showed evidences of unusual violence of glacial action, 
 being, as before remarked, only a few feet in thickness ; and in some 
 places in the same neighborhood it was entirely wanting, the bluff 
 material resting directly upon the coal - measure limestone. 
 
 An explanation of these facts is naturally sought for. The most 
 plausible seems to be, that glacial action extended more deeply 
 beneath the general surface here than elsewhere, and that the direc- 
 tion and character of the currents were such that the greater part of 
 the drift material was swept away to other places, leaving the lake 
 basin to be filled with water at the close of the glacial epoch. Fur- 
 ther investigations, however, are needed to decide such questions as 
 these. 
 
 It is understood that the most reliable information we can obtain 
 in relation to the general direction of ancient glacial currents will be 
 the identification of the transported materials with those at the 
 places of their origin. Very few observations of this kind 
 have yet been attempted in Iowa, and it is but fair to state that 
 those few are not now seen to harmonize clearly with the directions 
 of the glacial scratches just described. I refer to the reputed dis- 
 coveries of galena and native copper in several of the counties upon 
 the eastern watershed of the State. The only known localities from 
 which such materials might have been derived lie to the northeast- 
 ward, in a direction nearly at right angles with the eastern drainage 
 lines. Again, profusely scattered over the region between the Mis- 
 souri river and the middle of the State, so far northward as the 
 fourth tier of counties and probably much farther, are boulders and 
 fragments of reddish - colored quartzite, closely answering the 
 description given by Dr. Hayden of the rock which encloses the 
 pipestone of southwestern Minnesota, and suspected to be of the 
 same origin.* Should this be the case, it is not easy to see how 
 they could have reached their present locations with glacial currents 
 in the direction of the drainage of the western watershed, particu- 
 
 * bee P. V. Havden on the Geology of Northeastern Dakota; this JourDal, 
 January, 1867. 
 
148 REPORT OF STATE GEOLOGIST. 
 
 larly if they are of the age to which Dr. Hayden has referred the 
 rocks of that famous locality ; for in that case they can not be pre- 
 sumed to have ever existed much farther to the eastward. 
 
 The quartzite boulders in the region referred to are promiscously 
 intermixed with those of other metamorphic and of granite origin, 
 but those of the red quartzite are everywhere a little less waterworn 
 and more angular than the others, suggesting a less distance of 
 transportation, which would really be the case if derived from the 
 pipestone region. 
 
 INDIAN MOUNDS*. 
 
 The whole history of the American continent, previous to its 
 discovery by Columbus, is so wrapped in impenetrable mystery, that 
 the least memento of its ancient inhabitants is regarded with unusual 
 interest. Of the race which existed when Europeans first visited 
 America, and which now occupies a large portion of it, we have 
 comparatively full information ; yet of their origin or advent upon 
 the continent, we know nothing with certainty. 
 
 Notwithstanding this want of knowledge of their early history, the 
 evidence seems to be satisfactory, that an aboriginal race more 
 ancient than they, and having entirely different customs, once 
 inhabited the country now occupied by the northern and north- 
 western States, as well as parts of Canada. 
 
 The principal features of this evidence within the area named, 
 consists in the remains of ancient copper- mining in the Lake 
 Superior region, and the presence of what are commonly known as 
 Indian Mounds. It is believed that the present race of Indians, at 
 the time of the first visit of the whites, knew nothing of the working 
 of any metal, not even of lead, and they also seem to be in as utter 
 ignorance as ourselves concerning the origin of the mounds. 
 
 Thse mounds are rounded elevations of earth evidently scraped 
 up from the surrounding surface ; usually small, often scarcely 
 distinguishable, but occasionally of considerable size. They are 
 usually circular, sometimes oval, and even in some cases bear a 
 fancied resemblance in outline to some animal. They are almost 
 
 ■ From the Annals of Iowa for January, 1868. 
 
REPORT OP STATE GEOLOGIST. I49 
 
 invariably in groups, numbering from two or three, to fifty or more. 
 Sometimes they seem to be arranged on a definite ground - plan, but 
 are often distributed without order. 
 
 Concerning the purposes for which they were constructed we are 
 much in doubt, but they are usually regarded as memorials of the 
 dead. Human remains have often been found in connection with 
 them, but this is by no means invariable. When such remains are 
 found they are usually placed around the base of the mound, where 
 they are sometimes marked by the presence of flat stones, but they 
 seldom if ever occupy the centre, with the earth heaped upon them. 
 Rude pottery and other relics are frequently found with these 
 remains, to which the present race of Indians seem to be entire 
 strangers. 
 
 The mounds commonly occupy prominent, or otherwise interesting 
 locations, in the majority of cases being found upon the brow of the 
 bold characteristic bluffs which border the valleys of our Western 
 rivers, but are not unfrequextly located upon an elevated plateau 
 which is skirted around by a low range of bluffs or hills. Standing 
 among any of these mounds, one finds the surrounding scenery 
 invariably interesting, and often very impressive, showing that a 
 certain sentiment guided the builders in their selection of the ground, 
 but what this sentiment was, whether of religion, veneration of the 
 dead, or an appreciation of the beautiful and sublime in nature, we 
 are left to conjecture. They are quite numerous along the bluffs of 
 the Mississippi river, and the lover of that romantic scenery, having 
 sought out some point from which to obtain a view more beautiful 
 and impressive than the rest, will almost always find himself in the 
 immediate presence of a group of mounds. 
 
 During the progress of the State Geological Survey, many of 
 these interesting pbjects have been observed, but the press of other 
 matters has prevented that careful examination of them which the 
 interest of the subject requires. Along the bluffs of the Iowa 
 River between Iowa City and Columbus City, a large number of 
 them have been observed, a very numerous group of which occur 
 just below the mouth of English River, about twelve miles from 
 Iowa City. An interesting group is found on the land of Hon. 
 Eliab Doud, near the Des Moines River in Van Buren County. 
 
150 REPORT OF STATE GEOLOGIST. 
 
 Visiting Sac City, Sac County, last autumn, I observed several 
 mounds within the village, and having no time to devote to a careful 
 examination of these, Mr. D. Carr Early, an attorney of that place 
 has kindly furnished me with data for the following account of them, 
 accompanied by a carefully drawn plat, which I regret can not be 
 published with this article. 
 
 Sac City is pleasantly located in an abrupt bend of Raccoon river, 
 which sweeps around it upon the north, east and south, and rests 
 upon one of those level, or gently inclined spaces called by the 
 settlers " second bottom." They were doubtless true bottom lands 
 ages ago, long before the river had cut its valley so deep as it now 
 is, and long before the mound - builders occupied the ground, but 
 they are now, and were when the mounds were built, some of the 
 most interesting and fertile spots, and far above the reach of floods. 
 On the west the town is bordered by a moderately elevated bluff, and 
 thus the whole space is surrounded by strongly-marked topograph- 
 ical features rendering it one of the most interesting spots in the 
 whole region. It is about the centre of this space that we find the 
 mounds, and doubtless an appreciation of the surrounding features 
 guided the mound-builders in the one case, and the town-builders in 
 the other, in the selection of grounds. The mounds are eight in 
 number, arranged in a general direction from northeast to southwest, 
 but without regular order, the distance between the two extremes in 
 that direction being a little less than six hundred feet, and in the 
 transverse direction, less than one hundred feet. 
 
 Two of these mounds are oval in outline, and all the others are 
 circular. The oval ones are located further to the northeast, and 
 commencing with the first of these, which is near his residence, Mr. 
 Early gives their dimensions, as follows, progressing in the order of 
 their occurrence to the southwest. 
 
 No. 1, 96 feet in diameter, east and west, and 36 feet north and 
 south, and two feet high. 
 
 No. 2, 60 feet in diameter, east and west, and 30 feet north and 
 south, and two feet high. 
 
 No. 3, circular, 66 feet in diameter and 5 feet high. 
 
 No. 4, " 80 " « « 6 " 
 
 No. 5, " 60 " " « 3 a 
 
REPORT OF STATE GEOLOGIST. 15I 
 
 No. 6, circular, 60 feet in diameter and 3 feet high. 
 
 No. 7, " 50 " '' " 21 « 
 
 No. 8, « 60 " " " 3 « 
 
 It will be observed that three of these mounds are of exactly the 
 same dimensions, and that the long axes of two oval ones are in an 
 east and west direction, and not in the line of their distribution. 
 
 Nos. four, five and six have been dug through the centre to the 
 undisturbed earth, the public well having been dug through number 
 five, and the flatg - staff set in number six ; and nothing of human 
 remains or works of art have been discovered. 
 
 It is to be hoped that during the progress of the State work 
 sufiicient time may be devoted to the careful examination of these 
 works of the former owners of our soil. 
 
 LAKES OF IOWA — I AST AND PREsBNT. 
 
 After returning from the northern peat regions, I published in 
 several of the Iowa newspapers an article upon "Walled Lakes." 
 Subsequently the following article was communicated to the American 
 Naturalist, (Salem, Mass.,) and is inserted here, in place of the other, 
 because it contains some additional matter, and because it is fuller 
 upon the subject of those lakes : 
 
 Within the last ten or fifteen years a number of articles have ap- 
 peared in the newspapers and periodicals of the country in relation, 
 more particularly, to two small lakes of Northern Iowa. Some of 
 the writers have contented themselves with merely a- description of 
 what they saw, while others have told strange stories in which they 
 described the " remains of the wonderful handiwork of a departed 
 race of men." While in that part of the State during the past 
 season, excellent opportunities were had of examining both of the 
 lakes just named, as well as others of the same character, fourteen 
 in number, of which the following is a list : 
 
 1. Clear Lake, Cerro Gordo county. 
 
 2. Rice Lake, Worth county. 
 
 3. Silver- Lake, Worth county. 
 
 4. Bright's Lake, Worth county. 
 
 5. Crystal Lake, Hancock county. 
 
 6. Eagle Lake, Hancock county. 
 
]^52 KEPORT OF STATE GEOLOGIST. 
 
 7. Lake Edward, Hancock county. 
 
 8. Lake Mary, Hancock county. 
 
 9. Lake Flora, Hancock county. 
 
 10. Owl Lake, Humboldt county. 
 
 11. Lake Grertrude, Wright county. 
 
 12. Lake Cornelia, Wright county. 
 
 13. Elm Lake, Wright county. 
 
 14. Wall Lake, Wright county. 
 
 15. Twin Lakes, Calhoun county. 
 
 16. " Wall Lake," Sac county. 
 
 According to those stories the remains consisted of walls of huge 
 stones encircling the lakes like that ol an artificial fish-pond, so raised 
 as to prevent an overflow of water upon the adjacent low ground, 
 sloping to the water's edge with a pavement like a Mississippi levee, 
 rounded and graded with earth upon the top, forming a good road 
 upon which the Jehus of that departed race doubtless drove their elk 
 or buffalo chariots in pursuit of pleasure or of their daily vocations, 
 and the whole finished with a garniture of sage reflections upon the 
 mutability of human affairs. Such fantastic stories have rendered 
 those modest little lakelets so lamous that many pilgrimages have 
 been made to their borders with the hope of finding something to aid 
 in penetrating the mystery that shrouds the early human history of 
 our continent. 
 
 It is such lakelets as these, and their origin, that will now, in part, 
 engage our attention; and while showing the groundlessness of the 
 stories referred to, we hope to present still more interesting and 
 wonderful facts, because, in the realm of nature, truth is stranger 
 than fiction. 
 
 First, let us go back to their origin, for they originated from causes 
 so definite that we are often able to comprehend them as clearly as 
 if we saw them in operation ; and the time of their formation in rela- 
 tion to other geological changes is as accurately determined as that 
 of any other. Not only have the lakes had a definite origin, but, as 
 we shall presently see, some of them have also had an end, and we 
 know they once existed only by means of the records they have left 
 in the earth they once covered. Hence the addendum to the above 
 title — past and present. 
 
REPORT OF STATE GEOLOGIST. X53 
 
 Lakes have doubtless existed upon the earth's surface in every 
 geological age, but those of which we are speaking had their origin 
 at a period really very remote, when considered in relation to the 
 historic era, but very recent when compared with the geological ages 
 which preceded it. 
 
 All geologists are agreed that at the close of the Tertiary age, 
 after the stratified rocks had been formed, and before the present 
 condition of things existed upon the face of the earth, a long period 
 of time elapsed, during which the whole northern hemisphere, as far 
 south at least as the thirty -ninth degree of north latitude, was cov- 
 ered thickly and constantly with ice ; which time they call the Glacial 
 epoch. All are not entirely agreed as to what condition the ice was 
 in, whether floating in a shallow sea in the form of floes and ice- 
 bergs, or in the more completely frozen condition of a widespread, 
 continuous and southerly moving glacier ; yet the latterhy pothesis 
 is generally accepted as according with the greatest number and most 
 important of known facts. All are, however, agreed that the boul- 
 ders and pebbles which we see every where scattered over the face 
 of the country are of northern origin, and that they have received 
 their rounded forms by attrition in water or moving ice during the 
 time of their journeyings from their northern homes. We see those 
 boulders and the gravel upon the surface only, because we can look 
 no deeper, but we have abandant proof that they are intermixed with 
 all that incoherent mass of material which geologists call drift — 
 that material which meets our eyes every where, forms our soil and 
 subsoil, and covers all the stratified rocks like a mantle, except 
 where they have been bared by erosion. Some of the finer material 
 of the drift was doubtless brought from the north with the boulders, 
 but, with the exception of the latter, it has been largely derived by 
 attrition from the rocks over which the glaciers passed, or from those 
 which now underlie the drift. Thus the soil is nothing more than 
 pulverized rock, and the whole drift formation, composed as it is of 
 boulders, gravel, sand, clay and soil, had its origin as such through 
 the agency of ice. 
 
 At the close of the glacial epoch the ice disappeared from the 
 temperate zone, the present condition of the seasons was estab- 
 lished, and the continent assumed very nearly its present dimensions 
 20 
 
l^^ REPORT OF STATE GEOLOGIST. 
 
 and form. The northern part of the Great Valley — it is to this 
 region which more especial reference is made — was then unmarked 
 by strong topographical features, for it was traversed by no ranges 
 of mountains, nor by any rivers or streams. Shallow depressions 
 only, marked the surface, which were filled with water from the 
 rains and the melting ice. These were the primitive lakelets and 
 existed before any definite streams were formed. Where the depres- 
 sions were longitudinal, or connected in chains, they gave initial 
 direction to the courses of the streams into which the surface waters 
 were gathered, and carried away to the sea. These are the streams 
 of to - day, and their ceaseless flow, aided by the rains and frosts of 
 the unnumbered years that have passed since then, have worn their 
 own channels down, not only through the incoherent drift, but often 
 also through solid stratified rocks, the edges of which we see pro- 
 truding from their valley - slopes. Thus all the valleys of this 
 region are valleys of erosion, and it is meterological erosion alone 
 that has given it its most prominent physical features. 
 
 As one stands upon the broad, level prairies of Southern Iowa, 
 and sweeps the well-defined, ocean -like horizon with his level, he 
 finds the bubble everywhere resting upon the cross - wire, except 
 where the distant dark line of forest foliage reveals the presence of 
 a stream. Approaching this, the turface becomes undulating like 
 the smooth rolling of a sea; but looking closely he will see that 
 every depression leads into a still deeper one, until the" upper 
 branches of the streams are reached, the surfaces of which are often 
 more than one hundred and fifty feet below the prairie level from 
 which he started; and the surfaces of the larger streams are some- 
 time a hundred feet deeper still. The higher prairie surface of 
 to - day is the same surface which was left by the retiring waters at 
 the close of the glacial epoch, and the time which has passed since 
 then — that during which the valleys were formed — is called by 
 geologists the Terrace epoch, because the oscillations of the streams 
 from side to side of their valleys in the process of their erosion 
 have left frequent terraces of material which successively constituted 
 " flats " or " bottoms " bordering the streams, but which are now 
 far above the reach of their highest floods. The Terrace epoch 
 verges upon the present time, because the same streams still flow, 
 
EEPORT OF STATE GEOLOGIST. I55 
 
 and earthy matter is still carried by them to the sea, as rapidly per- 
 haps as it ever was, although only occasionally sufficient in amount 
 to muddy the water. Thus it will be seen how slowly the mightiest 
 operations of nature are performed; for this most recent of the 
 geological changes has doubtless required a length of time so great 
 that the human mind is incapable of comprehending it. 
 
 In Northern Iowa the prairie horizons are not so clearly defined, 
 as they are further to the southward, and it was doubtless so at the 
 beginning. The drift also contains more gravel and boulders there, 
 from the fact that nearly all of those materials originating, still farther 
 to the northward, their abundance diminished with the diminishing 
 force of the glaciers to the southward. Numerous irregular rounded 
 elevations or knobs mark the surface, between which are correspond- 
 ing depressions ; not produced, however, by erosion since the drift 
 was deposited, as the river valleys were, but are, like the knobs, 
 inequalities left by the glaciers. 
 
 Some of these depressions have become drained ; some of them are 
 still occupied by the lakelets, and some by peat marshes. Streams 
 are numerous in Southern Iowa and their valleys deep ; consequently 
 the country is so well drained that all trace of the primitive lakelets 
 is usually obliterated. But many of those streams have their rise in 
 Northern Iowa, and many of those lakelets still exist there, because 
 no accumulation of water beyond has sent a current across them to 
 cut a channel for their outlet. Lake- basins are sometimes hollowed 
 very deeply into the earth, showing bold exposures of stratified or 
 unstratified rocks upon their shores. But the lakelets of which we 
 we are speaking had their origin in shallow depressions left in the 
 surface of the drift alone at the close of the glacial epoch. By the 
 action of subsequent causes they, in certain regions, became " walled 
 lakes," for a majority of them are as worthy of that designation as 
 those are of which the fanciful stories have been told. Nor are lakes 
 of that character confined to Iowa alone, but are known also in Min- 
 nesota, Wisconsin, Michigan, and even in Connecticut, yet all except 
 two, one in Wright county and the other in Sac county, Iowa, seem 
 never to have been favored with the visits of an imaginative writer 
 to tell fanciful stories of their associated remains of human handi- 
 work. 
 
156 REPORT OF STATE GEOLOGIST. 
 
 It seemed necessary to make the foregoing statement of facts and 
 the geological principles which they involve, before attempting a 
 description of the lakelets themselves, that such a description might 
 thus be rendered more intelligible, and which is here given as the 
 result of long - continued observation of sixteen such lakelets in 
 Northern Iowa, including the two which have become noted as walled 
 lakes. They usually occupy an open prairie region. Sometimes 
 small groves are near them, but trees are often entirely wanting, 
 especially since the settlers mercilessly destroy them for fuel. They 
 are from .one to five miles across, but always very shallow, because 
 the undulations within which thoy rest are very gentle. None of 
 them are more than fifteen feet deep, and the majority are so shallow 
 that they permit a luxuriant growth of wild rice and other aquatic 
 plants from their bottoms over the whole, or a large part of their 
 areas, among which water -fowl find shelter and abundant food, but 
 which renders them rather uninteresting features of the landscape. 
 
 A true description of the so-called walls, but which we shall term 
 embankments, will be best understood if given in connection with a 
 description of their origin. 
 
 When a pile of sand, obtained from the river - shore, has been left 
 by the workman for a long time exposed to the washings of the rains, 
 the gravel which it contains, and which at first is hardly visible, 
 becomes in some cases even more conspicuous than the sand itself, 
 because a part of the latter has been wasted, while the gravel 
 remains. Thus, it has been upon an extended scale with the drift, 
 which, as before stated, is composed of boulders, gravel, sand, clay 
 and soil, although little except the latter is usually seen upon the 
 prairie and surfaces. Sometimes the drift is more than a hundred 
 feet thick, and all the boulders contained in the whole mass which 
 has been swept out to form the valleys, have gradually rolled down 
 upon their slopes, and many of them into the streams. Tor this 
 reason we usually find them more numerous upon surfaces that have 
 suffered erosion than anywhere else. Again, the ceaseless dashing 
 of a lakelet's waves stir up the finer material beneath its waters to 
 be carried away in the form of muddy water at the times of its over- 
 flow, leaving the boulders and gravel strewn upon its bed ; while they 
 may not be. seen at all upon the prairie - surfaces around them. This 
 
REPORT OF STATE GEOLOGIST. J 57 
 
 latter fact, being misunderstood, has led to the supposition that being 
 absent upon those surfaces they had been gathered up by human 
 hands and carried to the shores to build the "walls," while the 
 truth is, the embankments, as well as the presence of the materials 
 of which they are composed, are due to natural causes alone, and 
 their origin is wholly referable to the periodic action of ice, aided in 
 some degree by the force of the waves. 
 
 The water in the lakelets is usually very low in late autumn, and 
 when winter comes it is sometimes frozen nearly to the bottom in 
 their deepest parts, so that occasionally all the fish are killed by this 
 means. The ice of course freezing fast to the boulders as well as to 
 whatever else may be within its reach, and the expansive power of 
 from one to five miles of freezing water is exerted upon them in a 
 direction from the centre toward the shores — a power ■ much more 
 than sufficient to move the largest boulders upon those gentle slopes. 
 
 The embankments are from two, to six feet high, and from two, to 
 twenty feet across the top ; and always separate a low piece of 
 ground from the lake, because where the original shore is a little 
 abrupt, and higher' than the high - water level, no embankment is 
 formed, but the boulders are merely thrust against the shore with 
 such force as to render it steep, and often thickly studded with them. 
 Meeting no such obstruction on a marshy side, the material thrust 
 out, accumulates just where the expansive force of the ice is spent. 
 This process repeated year after year, from age to age, has cleared 
 the bottom of the lakelets of the boulders and other materials, and 
 piled them up in circular ridges upon their shores ; and these are 
 the "walls" which have excited so much wonder. It has been 
 observed that the embankments are heaviest on the sides opposite the 
 prevailing winds. This may be accounted for, at least in part, by 
 the fact that the ice being burthened with the material to which it 
 had frozen fast would thus be floated against those shores when the 
 spring floods had raised the water of the lakes ; and in part also by 
 the further fact that the dashing of the waters would be most con- 
 stant against those shores. 
 
 Thus it will be seen that whatever was originally upon the bottom, 
 whether boulders, gravel, sand or mud, has been carried to the shore, 
 
l^Q BEPORT OF STATE GEOLOGIST. 
 
 and Tvefind the embankment composed of all these materials arranged 
 in perfectly natural disorder. If boulders were numerous the 
 embankment is largely composed of them. If sand prevailed, a 
 broadly rounded embankment is formed, just such as we should 
 expect from such material; and where a peat marsh extends out 
 into the land an embankment of turf is thrown up at the water's 
 edge which being supported by living rootlets, is frequently high 
 and very narrow. The latter are somewhat numerous and are often 
 called beaver - dams ; but this is also a misconception, because 
 beavers never attempt to dam still waters. They dam running 
 streams to obtain ponds of still water. 
 
 Thus we see that the same natural force placed the boulders in 
 the embankments that brought them down from their northern homes, 
 namely, the expansive power of ice. The embankments are really 
 very interesting natural objects, and it is not strange that they have 
 attracted attention ; but with a correct knowledge of the action of 
 natural forces, it is difficult to understand how any one could suppose 
 that human hands had any thing to do with their construction. 
 There is certainly nothing in the arrangement of the materials that 
 indicates such an origin, and the liveliest imagination refuses to 
 suggest any object for which human beings could have desired them, 
 or-to point out any evidence of intelligence in their location and 
 plan. 
 
 If its crust should remain perfectly stable long enough, the earth 
 would become nearly a perfect sphere by the disintegration of its 
 exposed substance, and the levelling force of gravitation. It is true 
 that its inequalities of surface are now very insignificant compared 
 with the vastness of its bulk ; but in such a case there would be no 
 mountains, no islands, no continents. All would be an endless and 
 shoreless sea. The erosion of the river valleys, and the consequent 
 drainage of a majority of the primitive lakelets may be regarded as 
 the first steps in this levelling process, after the glaciers had ceased 
 from the Great Valley ; for its post - glacial geology seems to 
 warrant no subdivision into epochs such as are made for other regions; 
 therefore the whole is here referred to the Terrace epoch. Long 
 before this levelling process can approach completion other elevations 
 and depressions will be formed upon the changing surface, just as the 
 
REPORT OF STATE GEOLOGIST. 159 
 
 present seas and continents occupy the places of other seas and other 
 lands that existed long before them ; because perfect stability of the 
 earth's surface never has existed, and probably never will exist. 
 See then how small a part of such a result has been accomplished 
 even by the erosion of the valleys of the great Mississippi and its 
 branches. A part of the primitive lakelets, and a part of the 
 original surface of the drift still remain almost unchanged since their 
 formation. The prairies have still their ocean - like surfaces, and 
 the greatest change the lakelets have undergone in that immense 
 lapse of time is the formation of their insignificant embankments, if 
 aught in nature may be called insignificant. 
 
 Let us look a little to what has been accomplished by erosion in 
 the Great Valley * during the Terrace epoch, as before defined, and 
 we will find enough to excite our wonder and admiration. 
 
 Along the courses of what are now the Mississippi and Missouri 
 Rivers, large depressions formerly existed, which formed lake - like 
 expansions of those rivers. Thus, after the Mississippi had made 
 for itself a definite valley, but before it had cut its channel nown to 
 its present level through the rocky obstruction at the Keokuk rapids, 
 that portion of it which borders a large part of the eastern side of 
 Iowa was little else than a lake which averaged about five miles wide 
 and filled the space between what are now the bluffs that border each 
 side of its broad, flat valley. 
 
 This is proven by the existence there of the terraces, composed of 
 very fine sedimentary material, such as could have been deposited 
 only in comparatively still waters, and also by the existence in 
 that sediment of shells which inhabit still waters only — the same 
 species which now inhabit fresh - water lakes. River shells, such as 
 now exist in the river, are found on the sides of the bluffs near the 
 rapids at a bight of seventy feet above the present high - water mark ; 
 and since such beds of shells exist only at low - water mark when 
 alive, upward of eighty feet must be estimated as the hight of the 
 river above its present level at the time they lived. 
 
 It will be observed that river, and not lacustrine shells, are found 
 
 *it will be observed that the word mlley is used with two separate signiflcations 
 —one applied to the liydrographic basin drained by a certain principal stream 
 and its tributaries, and the other to the depreasioa occupied by any particular 
 stream, and which its own waters have cut out of the general surface. 
 
160 REPORT OF STATE GEOLOGIST. 
 
 near the rapids. This is accounted for by the fact that the obstruc- 
 tion which caused them, being a flinty formation, and not so easily 
 disintegrated as the other rocks over which the river runs, has existed 
 as such from it its earliest history. Consequently the water there 
 always had a considerable current, while further to the northward 
 there was too little current to produce a congenial habitat for 
 those shells. The estimated eighty feet is doubtless only a part of 
 the actual hight from which the erosion of the Mississippi Valley 
 has reached, because it now averages about two hundred feet deep 
 from the ge-aeral prairie surface. Thus we see that when that 
 lake - like expansion existed in the Mississippi river, its valley had 
 already been eroded to considerable depth, and the Terrace epoch 
 was well advanced. Bat on the other side of the State we have 
 proof of the existence in the early part of that epoch of a lake 
 which was larger and deeper than Lake Erie. This proof consists 
 principally in the presence there of a peculiar lacustrine deposit, 
 extending at least from the Big Sioux to the mouth of the Kansas 
 river, and from twenty to thirty miles on each side of thfe Missouri 
 river, through which the latter has cut its present valley, in some 
 places to a depth ot more than two hundred feet, before it reached 
 the drift which was deposited there during the Glacial epoch. That 
 material is known to have been deposited in fresh water, because 
 only fresh-water shells are found in it, and they are found in it from 
 top to bottom. It is known to have been deposited in still water, 
 because the same kinds of shells are now living in still water only, 
 and because the whole deposit is a fine, homogeneous material, with- 
 out sand, gravel, boulders, or any thing else, except what would have 
 been deposited in a lake of muddy water. 
 
 It has been claimed by a few geologists, that at the close of the 
 Glacial epoch a shallow fresh - water lake occupied the whole 
 hydrographic basin of the Mississippi, and that the fine soil and 
 subsoil of the prairies and other lands of the whole region, as well 
 as the peculiar deposit just referred to, are identical in their forma- 
 tion, and had theirs origin in one and the same broad lake. Upon 
 this hypothesis some have accounted for the origin of the prairies 
 and for the absence of trees upon them, but the fact is, prairies exist 
 upon both these deposits; and it would require direct effort 
 
KEPOET OF STA.TE GEOLOGIST. Jgl 
 
 to keep all kinds of indigenous trees from encroaching upon 
 kinds of indigenous trees from encroaching upon the prairies if there 
 were no annual fires. 
 
 It is not improbable that such a wide -spread sheet of fresh water 
 did exist at that time, and that a large part of the sedimentary- 
 material that composes our soil and subsoil had such an origin. But 
 that is widely diiferent in physical characters from the deposit under 
 discussion, which evidently had a different, as t, ell as a subsequent 
 origin. These circumstances seem to leave no room to doubt that a 
 well - defined lake existed there after the continent was in great part 
 dessicated, but before the great rivers had cut their valleys down to 
 any considerable depth. 
 
 The lake, although so large and deep, was doubtless filled with sedi- 
 ment to the general prairie level within a comparatively short time 
 after the glaciers ceased, just as the sediment of the same river 
 which then flowed into and from it, now speedily fills the reservoirs 
 of the St. Louis water - works, so that they must often be re - excav- 
 ated. Just as the same river would now fill with the same kind of 
 sediment, any depression, however large, if such existed in its 
 course. 
 
 The great Northern lakes are not thus filled, because their tribu- 
 tary streams are pure ; and their streams are pure because they flow 
 over geological formations that are not easily disintegrated; while 
 the main tributary of that ancient lake — the Missouri river — is 
 even now one of the muddiest streams on the globe. In the earlier 
 portion of the Terrace epoch, it was, if possible, more so; for then, 
 as now, it gathered up its sediment from that broad region occupied 
 by the friable rocks of the Tertiary and Mesozoic ages, stretching 
 far away towards the Rocky Mountains, at that time strewn with the 
 grindings fresh from those "mills of the gods" — the glaciers. 
 
 The formation of the basin in which the lake rested is known to 
 
 have taken place during the glacial period, because the drift with its 
 
 striated boulders now covers its bottom beneath the lacustrine 
 
 deposit, and because the cutting out of the river valley has exposed, 
 
 in a number of places, the stratified rocks which the drift rests upon, 
 
 the surfaces of which are scored and striated by the moving glaciers 
 
 of that period. It is known that the filling of the lake with sediment 
 21 
 
1Q2 REPORT OF STATE GEOLOGIST. 
 
 occurred in the early part of the Terrace epoch, because it was 
 filled up even 'with the prairie surfaces, which would not have been 
 done if the Missouri river had first eroded its valley to any consid- 
 erable depth below the lake. We know that the lake was so far filled 
 with sediment before it was drained, that it was little else than a 
 marsh, because the top of that deposit of sediment is now nearly 
 even with the higher prairie surfaces, and because the river bluffs 
 which it forms are as high as those formed of the usual materials, — 
 the drift and stratified rocks. 
 
 The physical characters of this lacustrine deposit are so peculiar 
 that they attract the attention of every person who becomes 
 acquainted with it, although a stranger might pass over the forma- 
 tion without observing more than its peculiar outline of bluffs. It 
 is perfectly uniform in character and color from top to bottom, and 
 a hundred miles of distance show no more difference than a hundred 
 feet. It is of a slightly yellowish ash color, except where rendered 
 darker by decaying vegetation, very fine, not sandy and yet not 
 adhesive.. At the surface it makes excellent soil, and is just as fer- 
 tile if obtained at a depth of two hundred feet. It is easily exca- 
 vated by the spade alone, and yet it remains so unchanged by the 
 atmosphere and frost that wells dug in it require to be walled only 
 to a point just above the water - line, while the remainder stands so 
 securely without support that the spade - marks remain upon it for 
 many years. Road - embankments, upon the sides of excavations, 
 stand like a wall, showing the names of ambitious carvers long after 
 an ordinary bank of earth would have disappeared. As that part of 
 the valley of the Missouri river below the lake was deepened during 
 the Terrace epoch by the natural process of erosion, the peculiar 
 material which its own waters had previously deposited, offered little 
 obstruction to that process, but was readily swept out again as 
 muddy water, and sent on its way to the sea. Thus no more of it 
 was cut out than served to form the valley, which is from four to six 
 miles wide, while the larger part remained, forming the bluffs and 
 extending far inland from the river. The tributary streams which 
 at first emptied into the lake, now traversed its ancient bed of sedi- 
 ment to the river, and cut down their own valleys to meet it. The 
 sides of these valleys, where they traverse that sedimentary deposit 
 
REPORT OF STATE GEOLOGIST. Jg3 
 
 are steep like the river bluffs, and the streams being smaller, their 
 valleys are narrow and very deep. This is particularly true of all 
 those Iowa streams that empty into the Missouri river above Council 
 Bluffs, and they thus present great obstacles to the construction of 
 lines of railway directly east and west through that State. For 
 this reason, and for the purpose of connecting with the great 
 Pacific Railway at Omaha, the more northern of those lines are 
 diverging to the southward down the valleys of the streams, instead 
 of crossing them, so that passengers will pass dry - shod through the 
 bed of that ancient lake, although many fathoms beneath the level 
 at which its waters used to rest. 
 
 The peculiar outline of the bluffs along the Missouri river valley 
 is one of the most interesting features of this remarkable deposit. 
 As one views them in the distance, and in their nakedness, for they 
 are often entirely destitute of trees, towering up from the level bot- 
 tom land, sometimes more than two hundred feet in bight ; so steep 
 in some places that a man can i^ot climb them, he can hardly rid 
 himself of the idea that they are supported by a framework of rocks 
 as other bluffs are. Yet not a rock or pebble of any kind or size 
 exists above their base of drift, except a few calcareous concretions 
 which were formed from the limy water that now percolates through 
 the whole mass. The form and arrangement of their numerous 
 rounded prominences sometimes present views of impressive beauty 
 as they stretch away in the distance, or form bold curves in the line 
 of hills. A few miles below the city of Council Bluffs they present 
 a full crescentic view to the westward, with the broad Missouri bot- 
 1;om stretching miles away from their base to the river. Their only 
 vegetation here is a covering of wild grasses, and as the mound -like 
 peaks and rounded ridges jut above each other, or diverge in various 
 directions while they recede backward and upward to the higher 
 lands, the setting sun throws strange and weird shadows across them, 
 producing a scene quite in keeping with that wonderful history of the 
 past of which they form a part. 
 
 THE IOWA COAL-FIELD. 
 
 The character of the field - woi'k of the survey has thus far been 
 that of a general reconnoisance, so that the boundaries of the 
 
154 REPORT OF STATE GEOLOGIST. 
 
 coal - field has not been determined with precision. So far as the eas- 
 tern and northern borders are concerned, they were at least approxi- 
 mately determined by the former geological survey. As that report 
 may not be possessed by all into whose hands this shall fall, a descrip- 
 tion of it, somewhat modified, is here given. 
 
 Draw a line on the map of Iowa from the southeast corner of Van 
 Buren county directly northward until it touches the south line of 
 Washington county; thence northwestward, keeping six or eight miles 
 to the northward of North Skunk river, to the south line of Marshall 
 county, a little west of its centre ; thence to a point three or four 
 miles northeastward from Bldora, Hardin county ; thence to Webster 
 City, Hamilton county: thence to Fort Dodge, Webster county, — and 
 you have approximately the eastern and northern borders of the 
 productive coal - field of Iowa. It is not claimed that all the coal of 
 the State exists southward and westward of this line, for it is already 
 known to exist in Lee, Henry and Washington on the other side of 
 it as well as in Muscatine and Scott counties, but it is believed that 
 very little coal will be found outside of the line thus designated. 
 
 Indications of coal are often found to the northward and eastward 
 of this line, but although the strata discovered are really coal- 
 measure strata, yet they are small isolated deposits, called outhers 
 by geologists, too small and too thin to aff"ord a workable bed of coal. 
 An exception to this rule is the large outlier extending from Musca- 
 tine almost to Davenport, where a small bed of coal has been worked 
 several years. A number of other small outliers have been discovered 
 in Johnson, Louisa, Benton, and doubtless may be also found in other 
 counties. The dip of the strata (the general dip, not the local dip ; 
 the general dip is too slight to be perceptible to the eye), being to 
 the southward and westward, it follows that at the northern and 
 eastern borders ot the coal - field it would have a thinner develop- 
 ment phan further within the field. Thus it will be seen that one 
 encounters greater hazard in exploring for coal along its thinning - out 
 border than he would within the main portion; yet some instances 
 are known of the existence of good mines very near the well - defined 
 border. 
 
 To the westward, and southward of the Des Moines river, it is not 
 known how far the productive coal formation actually extends, for it 
 
REPORT OF STATE GEOLOGIST. Ig5 
 
 passes beneath the unproductive series of coal - measure strata, and 
 beneath the heavy deposits of drift which are not deeply cut along 
 the dividing ridge of the State as they are in other parts. 
 
 Some coal has been found in Webster, Boone, Dallas, Madison, 
 Lucas and Wayne counties, west of the Des Moines river, beside the 
 thin bed in the upper coal - measures, along the Nodaway river ; 
 while Polk, Warren, Marion, Monroe, Mahaska, Wapello, Appanoose, 
 Davis and Van Buren, lying wholly or partly upon the west side, are 
 among the most important coal counties. Thus far, however, the 
 greater part of our coal is obtained northward and eastward of the 
 Des Moines river. Fcr further remarks upon the probabilities of 
 finding coal, by deep mining in the western part of the State, see 
 introductory chapter. 
 
 In that part of the productive coal - field thus far explored, there 
 is satisfactory evidence that no very deep mining will be necessary 
 in any part of it. This is inferred from the fact that the larger 
 streams are found to have cut their valleys down through all the 
 coal - measure strata to the sub - carboniferous limestone. 
 
 The distance down to this limestone from some of the higher 
 surfaces in this portion of the coal - field may sometimes be as great 
 as three hundred feet, but it probably will not exceed this depth 
 anywhere to the northward and eastward of the Des Moines river, 
 and may usually be expected at a much less depth. 
 
 Although the known area of the productive coal - field of Iowa, as 
 thus defined, is smaller than some have supposed, yet it will be seen 
 that its area is equal to that of the whole State of Massachusetts 
 beside which, it is expected that this area will be extended to the 
 westward by the discovery of coal at an increasing depth beneath 
 the surface. 
 
 SOIL, VEGETATION, &c. 
 
 There is probably not an equal area upon the earth that contains 
 proportionally less untillable land than does the State of Iowa. 
 
 By far the greater part of it is of drift origin, all of which is 
 scarcely less fertile than the rich alluvial and lacustrine soils found 
 bordering the rivers. 
 
 The drift deposit is very deep in all parts of the State, and 
 
^"VW 
 
 j^gg EEPORT OF STATE GEOLOGIST. 
 
 consists of so much fine material ttat the boulders, gravel and sand it 
 usually contains are almost nowhere the least obstruction to farming 
 operations. It has been estimated by some that seven - eighths of the 
 surface of the State are occupied by the prairies. These prairies 
 are always fertile and exist upon all varieties of soil, and their origin 
 can not therefore be due to any one of them. The greater part of 
 the forest trees are found in the vicinity of, and skirting the borders 
 of the streams ; and there is little variation in the kinds of trees 
 which compose the forests throughout the whole State that can be 
 ascribed to a difference of climate. Its principal forest trees are 
 several kinds of oaks, black and white walnut, hickories and pecan, 
 white and sugar maple, cottonwood and aspen, linden, red birch, 
 horse chesnut, box elder, ash, honey locust, red and slippery elm, 
 &c. It is a notable fact that all these trees will grow thriftily upon all 
 varieties of our prairie soil; even those whose chosen habitat is in the 
 neighborhood of the streams. 
 
 Thus far no chestnut nor beech have been found in the State, but 
 a few of the former have been introduced. Of introduced trees, 
 the black -locust succeeded well for many years and until it was 
 attacked by the borers in 1863, since which time almost all the trees 
 have been killed by this means. The osage - orange succeeds well in 
 at least the southern half of the State, where some as perfect and 
 effective hedges of it as one could desire have been in use a number 
 years, and its use is rapidly increasing. It has not yet been fully 
 tested in the northern part of the State. The prairies are always 
 covered with rank, and usually nutritious grasses, beside a great 
 variety of other plants which differ little in species throughout the 
 State. Of shrubbery there is almost as little difference ; hazel, 
 wild -plum and crab - apple being the principal kinds everywhere. 
 Of edible berries, the blackberry, raspberry and strawberry are the 
 chief. The common cranberry has not thus far been observed in the 
 State, although the so - called high - bush cranberry is occasionally 
 found in the northern part. It is not properly a cranberry, for it 
 has only a single seed like the black haw, to which it is closely 
 related, and which, except in the color of its fruit, it much resembles. 
 
 The adaptability of our soil to grapes, all kinds of orchard fruits, 
 
REPORT OF STATE GEOLOGIST. Ig7 
 
 grasses and staple cereals, is too well and widely known to need men- 
 tion at this time. 
 
 COAL AT DES MOINES. 
 
 No connected observations have yet been made in Polk county, 
 but while making visits to Des Moines on business, several of the 
 coal - mines in the vicinity of the cit}' have been examined. These 
 are those of Messrs. Redhead & Vincent, just- above the city on the 
 west side of the Des Moines River, and two or three on land of Mr. 
 C. C. Van, almost within the city, on the south side of Raccoon 
 River. 
 
 The most that can now be said of these mines is that the coal of 
 all is of good quality, much of it excellent. There is no doubt that 
 the high lands surrounding the city are all underlaid by a bed of 
 coal, but it is doubtless better and more workable at some points than 
 others. It is at present believed that the coal - beds now worked at 
 Des Moines belong to the upper part of the lower coal - measure 
 series, in which opinion Mr. St. John concurs, who has also visited 
 them, and has also traced out the geology of the Raccoon river 
 region with much care. If this opinion is correct, it is not improba- 
 ble that other beds of coal exist beneath the one now worked ; and if 
 our present estimate of the thickness of the lower coal - measure 
 series of strata is correct, a shaft commenced in the valley would 
 pierce all those strata by reaching a depth of from one hundred and 
 fifty to two hundred feet. It will of course be seen that we infer 
 that some of the mines worked in Marion and othjr counties are in 
 beds which belong in the series below the Des Moines coal, yet these 
 beds may or may not exist beneath those at Des Moines. 
 
 COLLECTIONS. 
 
 During the progress of the work, important collections of fossils, 
 minerals, rocks, coals, &c., have been made, the greater part of which 
 yet remain at the rooms in Iowa City for want of time to distribute 
 them as the law provides ; yet some excellent selections have already 
 been sent to the following - named Institutions, and their receipts 
 taken therefor, viz : State Agricultural College, four boxes ; Cornell 
 College, one box ; Iowa College, one box ; Tabor College, one box. 
 
Ig3 REPORT OF STATE GEOLOGIST. 
 
 These specimens have all been carefully ticketed and plainly - written 
 catalogues sent with each collection, so that by observing the number 
 written upon the small ticket which is pasted upon each specimen, 
 and the corresponding number in the accompanying catalogue, its 
 name, locality, and geological position will all be known. A com- 
 plete record of all is kept in the oflSce, so that in case of the loss of 
 the catalogue, it can be restored by writing to the office and sending 
 a list of the numbers upon the specimens. 
 
 Every specimen, great and small, receives this small ticket, about 
 a quarter of an inch in diameter, as soon as they are unpacked at 
 the office and washed, and the locality and geological position at least 
 are immediately recorded, so that whatever disarrangement they may 
 afterward suffer, so long as the tickets remain pasted upon them, 
 their history and character can always be known. 
 
 Thus far the collections have been made principally from the 
 upper, middle and lower coal- measures, the sub - carboniferous, and 
 part of the lower Silurian rocks. Beside this, the specimens con- 
 sist chiefly of coal from different parts of the coal-field; grey, white 
 and fibrous gypsum from Fort Dodge ; sulphate of strontia from Fort 
 Dodge ; geodes from Bentonsport, &c., &c. 
 
 While examining the collections during the winter of 1866-7, 
 we found among them fourteen or fifteen species and three new 
 genera which were new to science. These have been described under 
 the authorship of White and St. John, and published gratuitously by 
 the Chicago Academy of Science, the survey receiving credit for 
 priority of labor. The new genera referred to are Meekella, Crypta- 
 canthia, and Tomoceras, the following being the full list : 
 
 Amplexus fragilis Keokuk limestone. 
 
 Aulosteges spondyliformis Upper coal - measures. 
 
 Axophyllum rudis Upper coal - measures. 
 
 Beyrichia petrif actor St. Louis limestone. 
 
 Beyrichia foeioida Upper coal - measures. 
 
 Crania modesta Upper coal-measures. 
 
 Cryptacanthia compada .\ Upper coal-measures. 
 
 Crypioceras Springeri Upper coal - measures. 
 
 Cythere simplex St. Louis limestone. 
 
REPORT OF STATE GEOLOGIST. Ig9 
 
 Hydreionocrinus verrucosus Upper coal- measures. 
 
 Meekella striatocostata {Cox sp.) Upper coal - measures. 
 
 Nautilus divisus Upper coal - measures. 
 
 Pinna Hinrichsiana St. Louis limestone. 
 
 Tomoceras Oillianum Upper coal - measures. 
 
 Besides the above, numerous specimens of a small object was found 
 in the upper coal - measure marlites, ^Yhich is supposed to belong to 
 the Protozoan genus Amphistegina, specimens of which have been 
 sent to Dr. William B. Carpenter of England for examination, since no 
 one in our country is known to be giving especial study to those 
 unusual objects. 
 
 22 
 
LETTERS 
 
 OF 
 
 MR. O. H. ST. JOHN 
 
 ASSISTANT STATE GEOLOGIST. 
 
GEOLOGY OF THE RACCOON RIVER REGION. 
 
 During the past season, through the kindness of the Director of 
 the Geological Survey, the writer was permitted to spend a consider- 
 able portion of the autumn in the country traversed by the Raccoon 
 rivers, with the view of studying the stratigraphical geology of that 
 section of the State. The counties of Polk, Dallas, Guthrie, Greene 
 and Carroll held out important inducements to that end, and the 
 result of the season's work was satisfactory in a high degree. The 
 counties lying to the southward and bordering upon those above 
 mentioned, had been already examined, and their geological struc- 
 ture made known through the labors of Dr. White during the pre- 
 vious season. But heretofore little, I may say nothing, was known 
 of the character of the strata in the country drained by the Rac- 
 coon rivers, save that they were coal - bearing. Their relations to 
 the well - developed upper coal - measures found along the North, 
 Middle and South rivers, in Madison and adjoining counties, and to 
 the lower coal - measures which are exposed on the Des Moines, 
 remained to be determined. Nor was the nature of the coal - beds 
 themselves any better known beyond the localities where they made 
 their appearance ; and their relations to one another were unex- 
 plained. Indeed, the field was new, and gave promise of valuable 
 results in behalf of the economic interests of the State. 
 
 To facilitate our review of the ground, I will at once introduce a 
 vertical section of the strata with which we have to deal, presenting 
 only such details as shall be essential to our purpose. 
 
171 
 
 REPORT OF STATE GEOLOGIST. 
 COAL-MEASURES.^ 
 
 p 
 
 
 
 Sandy shales and sandstones. 
 
 
 C3 
 
 •a 
 
 w 
 Q 
 
 § 
 
 50 FEET. 
 
 Black fossiliferous shales and sandy shales, 5 to 10 ft. 
 COAL C. 
 
 Clays, with layers of compact, Impure, fossiliferous 
 limestone, 40 feet and upwards. 
 
 Lower black shales of upper group. 
 
 
 
 
 •> 
 C 
 
 5 
 
 
 H 
 
 
 n 
 
 5 
 
 
 Clays, arenaceous shales and saAdstone. 
 
 H 
 
 70 TO 90 FEET. 
 
 COAL B. 
 
 Clays, arenaceous shales and bands of micaceous 
 sandstone: towards upper part, layers of impure 
 fossiliferous limestone, and locally developed black 
 shales— 70 to 90 feet. 
 
 
 
 
 
 
 o 
 
 Q 
 W 
 o 
 
 5 FEET. 
 
 Layers of argillaceous, fossiliferous limestone. 
 
 
 5 TO 10 FEET. 
 30 TO 50 FEET. 
 
 Black shale, clays, impure limestone band. 
 COAL A. 
 
 Variegated clays, with nodular bands and arena- 
 ceous layers — 30 to 50 feet. 
 
 
 
 
 
 o 
 
 
 20 TO 45 FEET. 
 
 Sandstone, 20 to 45 feet. 
 
 < 
 > 
 
 10 TO 15 FEET. 
 
 Argillaceous and arenaceous shales, 10 to 15 feet. 
 
 Des Moines Coal, 3 to 5 feet. 
 Concretionary sandy shales. 
 
 
 
REPORT OF STATE GEOLOGIST. J 75 
 
 It will be observed from the section that we have all three of the 
 coal - measure series represented in this region, but of the lower and 
 upper measures only their upper and lowermost members are acces- 
 sible. The middle coal-measures, however, here attains its full 
 development, and it is with this division our attention shall be 
 mainly occupied. 
 
 MIDDLE COAL-MEASURES. 
 
 The middle series of coal - measures, as developed in this part of 
 the State, may be sub - divided into three groups, each of which 
 possesses its own peculiar lithological characters in distinction from 
 the other groups. The lower group has a thickness of from forty to 
 seventy feet, the middle one eighty to one hundred feet, and the 
 and the upper groups, probably, upward of fifty feet ; making the 
 average thickness of the middle series about two hundred feet. 
 ■Towards the top of each of the groups the deposition of carbona- 
 ceous matter took place, forming as many distinct coal -horizons. 
 The upper bed, coal 0, is the most valuable one of the middle series. 
 Its thickness varies between fifteen and thirty inches, and is a work- 
 able bed. It is overlaid by two to four feet of dark shales, 
 abundantly charged with fossil remains which serve to distinguish 
 this coal horizon from any of its associates. At the base of the 
 upper group a well - marked carbonaceous bed is found, but it seldom 
 presents any coal, though the highly carbonaceous black shale, 
 capped by a single layer of compact argillaceous rock, is always met 
 with wherever it has not been denuded. A bed of sandstone five to 
 ten feet thick, forms the upper bed of the middle group, immediately 
 beneath which the second carbonaceous horizon, coal B, occurs. 
 This bed is very variable in thickness, ranging from one inch to two 
 feet, and presenting even in short distances all the gradations from 
 a black shale to coal of an excellent quality. It constitutes, how- 
 ever, a constant horizon, notwithstanding at certain localities it 
 becomes so attenuated as scarcely to retain its identity. In the 
 middle and lower portions of this group local developments of dark 
 shales, sometimes more or less carbonaceous, are not unfrequent, 
 beside there are bands of impure fossiliferous limestone, and the 
 lower half is made up of clays and arenaceous beds. The lower 
 
]^76 REPORT OF STATE GEOLOGIST. 
 
 group is limited above by several layers of argillaceous lime rock, 
 five to ten feet below which coal A, occurs, varying from three to 
 fifteen inches in thickness, overlaid by black shale and a band of 
 compact argillaceous rock. This latter horizon is subject to the 
 most remarkable variations of any of the beds previously described. 
 Sometimes the black shales have a most exagerated development, and 
 then, again, the layer of earthy rock is reduced to a lenticular 
 nodular band, or lost entirely. The base of this group rests 
 immediately upon the sandstone overlying the Des Moines coal, 
 which is regarded as the upper bed of the lower coal-measures. 
 
 The coal which is being so extensively mined in the vicinity of 
 the city of Des Moines, presents the interesting feature of three 
 distinct layers of coal separated by thin seams of clay, so that the 
 whole are wrought as one bed, the maximum thickness of which is 
 about five feet. But, independently, the layers are very variable in 
 thickness — sometimes the upper ones are the most important, then 
 again the lower ones become the best developed, as may be' seen by 
 examining the out - crops upon either side of the Des Moines, in the 
 upper part of the city. The middle stratum, however, is more con- 
 stant in this respect, averagmg about eighteen inches in thickness, 
 while the upper and lower ones range from six to thirty inches. 
 Overlying the Des Moines coal, which is practically but one bed, 
 we find about ten feet of clay, capped by eight to twelve feet, or 
 more of soft sandstone, which in turn is overlaid by variegated clays,' 
 exhibiting a vertical section of the strata associated with this coal 
 horizon of about forty feet. The line of outcrop of the coal is 
 probably fifteen to twenty feet above the level of the river, and 
 could not be more accessible for advantagous mining. Its product 
 has received the local name of " Diamond coal," and in quality it is 
 esteemed the best coal in this market. The importance of this coal 
 to the manufacturing interests of Des Moines can not be overesti- 
 mated. 
 
 Now, that we have made ourselves somewhat familiar with the 
 characters associated with the Des Moines coal on the Des Moines 
 river, let us at once transfer our examinations to the Raccoon river 
 coal-field proper, immediately to the westward. Taking the road 
 which passes along the north side of the valley of the Raccoon, 
 
REPORT OF STATE GEOLOGIST. -^jn 
 
 three miles above Des Moines, at Fagan's Mill, in the bluiF on Wal- 
 nut creek, at an elevation of about sixty feet above the stream there 
 are indications of a thin stratum of coal, overlaid by black shales 
 and a layer of clayey limestone, and in the slope above, clays and 
 fragments of impure, thin - bedded limestone, affording us our first 
 section in the middle coal-measures. The exposure represents the 
 upper portion of the lower group, including coal A. This bed has 
 been prospected by drifting into the bank, but we presume it was 
 found too thin for profitable working, as the entry is now in 
 ruins, and appears to have been abandoned for some time. 
 
 The fact that the coal at Fagan's mill holds, apparently, a position 
 forty feet above the Des Moines coal, very naturally would seem to 
 offer conclusive evidence that this bed overlies the latter by as many 
 feet as constitute the difference in their respective levels above the 
 level of the Des Moines river. It is not thus, however, the geologist 
 arrives at his conclusions regarding the order of superposition of 
 strata ; else discrepancies would constantly embarrass the observer, 
 and errors without number would unavoidably accumulate in the end, 
 compelling all mining enterprises to resort wholly to the expensive 
 and uncertain expedient of practically demonstrating the existence of 
 mineral wealth, which experience proves has oftener than otherwise 
 resulted in the irrecoverable expenditure of millions. Therefore if 
 we would master the details of structural geology, thereby rendering 
 our science subservient to the interests of man, we must apply our- 
 selves diligently to the study of all the various strata, both their 
 lithological and external peculiarities, and the organisms they contain, 
 which latter, though they may range through a greater or less 
 thickness of strata, always give us reliable data in the manner of 
 their association in the various horizons, which will render invaluable 
 aid in our examinations, as I shall presently endeavor to show. 
 
 Four or five miles above Fagan's mill, in the bluff banks and 
 
 ravines upon the north side of the Raccoon, in the vicinity of Fitzsim- 
 
 mon's mills, several layers of impure limestone are quarried for 
 
 building stone, which give a tolerable exposure at an elevation of 
 
 twenty feet above the stream. A quarter of a mile or less above, 
 
 however, just below the mills, the same beds out -crop in the river 
 
 bank ten to fifteen feet below tlieir level at the quarries. By the 
 23 
 
178 EEPORT OF STATE GEOLOGIST. 
 
 association of fossils found in these thin layers of argillaceous lime- 
 stone, we at once recognize them as belonging to the horizon 
 observed at Pagan's mill, though then shown only by a few fragments 
 out-cropping here and there a few feet above the thin coal A. By 
 making a liberal estimate of the fall of the river between the two 
 above - named localities, the beds at Fitzsimmons' are found to occupy 
 a much lower level by, probably, not less than thirty feet, showing that 
 the beds gently incline as we ascend the valley to the westward from 
 Des Moines, which has carried coal A below the river bed at Fitz- 
 simmons'. The inclination of the strata is so gradual, and the beds 
 are so subject to local inequalities and undulations, that it would be 
 extremely difficult, to say the least, to make any trustworthy observa- 
 tions on the general dip of these beds at any one exposure. This is 
 true, too, of nearly all the exposures in this region ; so that the 
 impracticability, the absurdity, of recognizing equivalent horizons at 
 remote localities by comparing their positions in reference to a 
 common base of level, will be apparent from the illustration afforded 
 by the localities already mentioned. 
 
 The next considerable exposures ascending the river are found in 
 the vicinity of the Boone estate, and a couple of miles above in the 
 bluffs upon the right side of the valley (sections twenty - six and 
 twenty - seven, township seventy - eight, range twenty -seven, Dallas 
 county), near Mr. Benjamin Colton's, to whom I am indebted for my 
 knowledge of this locality. The strata at this point outcrops in the 
 sides of deep, narrow ravines, and though the exposures are limited 
 and isolated, they exhibit when brought together nearly seventy feet 
 thickness of strata, all of which pertain to horizons higher in the 
 series than those heretofore mentioned, or to the middle groups of 
 t"he middle coal. Sixty to seventy feet above the river, coal B is met 
 with, resting upon clays, and overlaid by sandy clays and a five -foot 
 bed of sandstone, embedding large trunks of ancient club -mosses; 
 and above the sandstone the lower black shales of the upper group, 
 capped by a foot layer of impure limerock charged with fossils, com- 
 pletes the top of the section. Thirty feet below coal B, layers of 
 compact argillaceous rock, interbedded with dark shales and varie- 
 gated clays, are seen ; but in a thickness of seventy feet only the one 
 little six - inch bed of coal occurs. 
 
REPORT OF STATE GEOLOGIST. ]^79 
 
 Four miles nearly due north from the above locality, on the head- 
 waters of Sugar creek, near Mr. Huston's place, coal B outcrops in 
 the margin of the stream, presenting the same association of beds 
 as noted in the section near Colton's. Here, however, the black 
 shales at the base of the upper group have a much greater develop- 
 ment than at the former locality, and the bed is finely exposed all 
 along the creek for half a mile or more above, when it disappears 
 beneath the bed of the stream at the quarry on Mr. Frank Graham's 
 farm (section six, township seventy - eight, range twenty - six, Dallas 
 county). The same coal- bed also appears on a branch of Walnut 
 creek near Mr. John Cutler's place, four or five miles north of Hus- 
 ton's. 
 
 Regaining the valley, three miles above the confluence of the 
 North Raccoon at Vanmeter's Mills on the South Raccoon, the bluffs 
 on the left bank give a very perfect exposure of the upper half of 
 the middle group. Coal B, a thin band of rotten coal three to six 
 inches thick, is seen in the face of the bluffs twenty - five feet above 
 the river, and overlaid by the upper sandstone of this group. Below 
 the coal, clays and layers of argillaceous rocks alternate to the water 
 level. The lower black shale of the upper group does not appear 
 in the section at Vanmeter's, but in the bed of a little branch on Mr. 
 Miller's place, and at the crossing of the Winterset road on the 
 Bulger, two miles south of the mills, the uppermost layers of the 
 sandstone appear in the bed of the stream, supporting a few feet of 
 clays, upon which rests the black shales and bands of clayey lime- 
 stone, presenting a section identical with that at Colton's, five miles 
 below. It will further be observed that the position of coal B, at 
 this locality would still indicate a slight westerly inclination of the 
 strata. 
 
 Again let us make a detoar, and ascend the valley of the Bulger 
 to the southwestward. This little valley has been selected for the 
 route of the C, R. I. & P. Railroad, in its ascent from the Raccoon 
 Valley to the " Quaker Divide," and consequently its importance 
 as a great commercial thoroughfare far exceeds that of the larger 
 streams of which it is but one of many diminutive afiluents. Near 
 the head waters of the Bulger, and just within the borders of Madi- 
 son county, limestone ledges are met with, which doubtless belong 
 
180 REPORT OF STATE GEOLOGIST. 
 
 to the upper coal-measures, and are high above any rock exposures 
 we shall see on the Raccoon rivers. These ledges afford a very excel- 
 lent, durable building stone, and when the railroad shall have been 
 completed to these quarries, their value will be greatly enhanced. 
 There are also thin beds of carbonaceous shale in the upper coal- 
 measures, as shown by Dr. White ; and on the head - waters of Bear 
 creek, on the southern line of Dallas county, in the vicinity of Mr. 
 Price's, one of these black shale horizons of the upper coal-measures 
 is found underlying limestones, very similar if not indentical with 
 those on the upper course of the Bulger. The elevation of these 
 quarries above the South Raccoon at Vanmeter's can not be far from 
 two hundred feet ; and when we take into consideration the inclina- 
 tion of the middle coal strata in the same direction, we may safely 
 estimate their elevation above coal B at one hundred to one hundred 
 and fifty feet. 
 
 From Bear creek we strike across the beautiful upland prairie, 
 known as the ''Quaker Divide," to the northward, and gain the bights 
 overlooking the valleys of the South and Middle Raccoon rivers 
 in the vicinity of their confluence. The south side of the valley is 
 bounded by steep, wooded bluffs, and a low sandstone ridge crowned 
 with forests rises between the two streams The north side of 
 the valley rises, terrace upon terrace, to the general upland level, 
 and dotted in every direction with thrifty farms. ■ Upon one of these 
 high benches, on the east bank of the Middle Raccoon, the prosper- 
 ous manufacturing village of Redfield is located. 
 
 Descending into the valley, the first exposures we meet with in the 
 river bank, just below the Newport Woolen Mills, presents arena- 
 ceous beds crowded with lenticular concretions, which strongly recall 
 the deposits underlying the coal at Des Moines. Ascending thence 
 the Middle Raccoon, a short distance above its mouth, in the left 
 bank (section nine, township seventy-eight, range twenty-nine, Dallas 
 county) on lands belonging to J. Ward Redfield, Esq., a bed of 
 coal outcrops, overlaid by clays and a heavy - bedded sandstone, 
 thirty to fifty feet thick, presenting a section of strata essentially 
 like tnat described at Des Moines. The Redfield coal, like the Des 
 Moines bed, is not a single bed, but consists of two layers separated 
 by a thin clay parting. It differs, however, from the Des Moines 
 
REPORT OF STATE GEOLOGIST. 
 
 181 
 
 bed, in being one layei- less, although it still retains an aggregate 
 thickness of three feet. With these facts alone we could hardly 
 prove beyond a doubt the identity of these banks. It is well known 
 that coal-beds are very variable in their physical characters, and 
 not unfrequently the lithological characters of the associated strata 
 become changed to such a degree as to be almost or quite unrecogni- 
 zable at distant localities. However, in this instance, we are not left 
 in doubt regarding the validity of the identification ; and notwith- 
 standing the exaggerated enlargement of sandstone above the cOal 
 at Redfield, we shall be able to show conclusively that the Des Moines 
 and Redfield coals belong to one and the same horizon. 
 
 If we take the valley road leading from Redfield to Panora, we 
 will meet with exposures of the sandstone, which overlies the Red- 
 field coal, at frequent intervals in the bluffs between Redfield and the 
 Musquito. A short distance above the Musquito creek bridge, in the 
 bluffs on the east side of the creek, at Parker's bank, coal A of the 
 middle series outcrops at an elevation of thirty feet above the level of 
 the Middle Raccoon. The coal is six inches thick, and is overlaid by 
 the black shales, band of argillaceous lime -rock and clays usually 
 associated with this bed. At Piatt's bank, a few hundred yards 
 above, the black shales have increased in thickness from eighteen 
 inches to forty inches ; the " cap - rock" only exists as thin pyritif- 
 erous modules, above which brown, yellowish and grey shales occur, 
 which are in places charged with fossils. The coal is about the same 
 thickness at both banks, but in other respects they could hardly be 
 more dissimilar. About a quarter of a mile southwesterly from Par- 
 ker's bank, a ledge of rocks juts into the Middle Raccoon, which upon 
 examination proved to be the upper argillaceous layers of the lower 
 group of the middle series, and present almost the same characters 
 they possess at Fitzsimmons', eighteen miles east. Although these 
 beds are not seen at Parker's and Piatt's banks, having been removed 
 by denudation, they nevertheless overlie that coal-bed, and their 
 occurrence in the river margin, thirty feet below the level of the coal 
 at Parker's, indicates a southwesterly inclination of the beds equiva- 
 lent to about one hundred feet to the mile at this locality. Presently, 
 however, we shall see the sequence of these- beds fully exemplified, 
 and also their relation to the coal at Redfield. 
 
Ig2 REPORT OF STATE GEOLOGIST. 
 
 Crossing the South Raccoon a short distance above the confluence 
 of the Middle Raccoon we ascend by a steep acclivity to the uplands 
 upoi) the south side of the valley. The road passes over a natural, 
 though somewhat obscure, exposure composed of layers of impure 
 limestone, identical with those last observed in the banks of the 
 Middle Raccoon near Mr. Fee's. This band, clays and fragments 
 of hard, earthy lime - rock are seen, and a faint trace of a carbon- 
 aceous band indicates the horizon of coal A, at a level of sixty - five 
 to seventy - five feet above the coal at Redfield, a mile to the north- 
 east. Continuing up the valley of the South Raccoon two miles 
 above the last - named locality, on the borders of Dallas and Guthrie 
 counties, one of the most interesting and important exposures in the 
 valley was examined. The discovery of this locality I owe to Mr. 
 Peter Marshall, who by intelligently - directed practical examinations 
 had already made himself perfectly familiar with the local geology, 
 and to the writer it is a particular pleasure here to acknowledge the 
 valuable co - operation he gave me in ray field - examinations, and the 
 kindness he showed to the members of my party during our stay in 
 this vicinity. At this locality, which we shall call the " Marshall 
 section," the strata have a very decided westerly dip. At the lower 
 end of the bins', a six -inch bed of coal outcrops at the water-level, 
 and which is overlaid by a bed of black shales and impure limestone, 
 five to eight feet of clay, and four feet of earthy lime -rock with 
 clayey partings, upon which thirty feet or more of clays, sandy shales 
 and thin beds of sandstone are superimposed, afibrding a complete 
 section of forty - five feet, the lower part of which presents a typical 
 exposure of coal A and the beds forming the top of the lower group 
 of the middle coal - series. No other locality, to my knowledge, ex- 
 hibits so satisfactorily at a single exposure the direct order of super- 
 position of the members which form the upper part of the lower 
 group and the base of the middle group of this series. Five hundred 
 yards below the "Marshall section," coal A outcrops in the hill -side 
 forty feet above the level it occupies at the latter exposure. The 
 easterly - rising of the strata at this locality corresponds precisely 
 with what was observed in connection with the same horizons on 
 Musquito creek, four miles northward. The forces which upraised 
 the Des Moines coal above the level of the Middle (;Raccoon at 
 
REPORT OF STATE GEOLOGIST. 283 
 
 Keilfield, also uplifted the superincumbent strata of the middle series, 
 giving rise to a broadly - arched anticlinal ridge, upon whose flanks 
 the strata sweep down in opposite directions, and gradually accumu- 
 late vertically, bed upon bed, as they approach the axis of the shallow 
 synclinal depression Which occupies the intervening country between 
 the Des Moines and the mouth of the Middle Raccoon, a distance 
 of thirty miles. Hence, we shall at once understand the occurrence 
 of beds pertaining to the middle and upper groups of the middle 
 coal, as at Vanmeter's, at the same levels occupied by much lower 
 strata whose edges are exposed high upon the flanks of the two 
 parallel anticlinal ridges which define the east and west margins of 
 the intervening depression. 
 
 Nearly three miles west of the Marshall section, at Miller's coal- 
 bank, a six to ten inch coal - bed has been opened, which is equiva- 
 lent to the black shale horizon at the base of the upper group of the 
 middle series. It is very seldom that coal is found with this bed, and 
 its occurrence at this locality aS'ords an interesting illustration of the 
 local deposition of a thin layer of coal at the bottom of a well- 
 characterized and constant horizon of carbonaceous shales. Coal B, 
 and the overlying sandstone are not exposed at Miller's bank; but 
 in the banks of the South Raccoon, south, of Morrisburg, the sand- 
 stone and carbonaceous horizon above were observed, and in a boring 
 half a mile above, a bed of coal is said to have been found, which may 
 be equivalent to coal B. 
 
 Four miles south of Morrisburg, on Deer creek (section twenty, 
 township seventy - eight, range thirty, Guthrie county) at Lonsdale's 
 bank, a two - foot bed of coal outcrops, and is overlaid by three to 
 four feet of dark, highly - fossiliferoua shales. Ten feet above the 
 coal a soft, yellow sandrock is imperfectly exposed, between which 
 and the dark shales a second band of impure coal is said to occur. 
 In the slope forty - iive feet above the coal, layers of compact grey 
 limestone are seen, which is the highest rock exposed at this locality. 
 The coal at this locality is regarded as the uppermost coal - bed of 
 the middle - series, or coal C. It is one of the conspicuous palaeon- 
 tological horizons in the coal - measures ; containing an assemblage 
 of minute fossil - forms, which readily distinguish this from all other 
 carbonaceous horizons of the middle coal-measures. The present 
 
jgj. REPORT OF STATE GEOLOGIST. 
 
 workings at this locality are on lands belonging to Mr. John Lons- 
 dale of Dale City. The coal varies in thickness from twenty to thirty 
 inches. Its elevation above the creek greatly facilitates the working 
 of the bank. The coal is excellent in quality, and with the rapid 
 settlement of the beautiful country about, it will prove an important 
 source of wealth to that section. 
 
 Four miles west of Dale City, on Spring Branch of Beaver creek, 
 near Mr. Loring Mann's, horizons equivalent to coal B and the lower 
 carbonaceoas'horizon of the upper group are found; but neither of 
 the carbonaceous horizons are here coal -bearing. However, higher 
 up the Beaver, two miles northwestward from Spring Branch (in 
 lot 4, section 5, township 78, range 8, Guthrie county,) the same 
 beds appear, presenting a marked contrast to their appearance 
 on Spring Branch. Coal B here affords a twelve -inch bed of coal; 
 and twelve to fifteen feet above, the lower black shales of the upper 
 group are underlaid by a four - inch layer of coal, presenting pre- 
 cisely the same appearance possessed by this bed at Miller's bank. 
 Mr. Thos. Coleman informed us of other localities in this neighbor- 
 hood where the same bed has been seen, and it is not improbable 
 that coal B may be found much thicker in this vicinity. Indeed, at 
 Marshall's coal bank, on Long Branch in the southeast corner of 
 Guthrie county, a very good bed of coal one to two feet thick is 
 being mined, and which, I am inclined to believe, belongs to this 
 horizon. 
 
 Thus far our examinations have been confined to the valleys of 
 the Raccoon and South Raccoon rivers, along a nearly direct line 
 extending west from Des Moines forty -five miles into the interior. 
 We have had opportunity to study all the members of the middle 
 coal -series, from the Des Moines coal of the lower coal-measures 
 to the arenaceous deposits and limestones at the base of the upper 
 coal- series. And it now remains only to describe the principal coal- 
 exposures found along the Middle and North Raccoon rivers, both of 
 which streams have afforded excellent facilities in the prosecution 
 of the investigations of this division of our coal - measures. 
 
 At frequent intervals along the Middle Raccoon between Mr. Fee's 
 and Huggin's branch two miles above, rock - exposures appear in the 
 bluffs, and as we ascend the stream the westerly inclination of the 
 
REPORT OF 8TATB GEOLOGIST. 185 
 
 strata brings successively to view higher and higher beds, comprising 
 the arenaceous and argillaceous bulk of the lower half of the middle 
 group of the middle series; and, finally, in the high bluff opposite the 
 mouth of Huggin's branch, the remainder of this group may be seen, 
 crowned by the bed of sandstone. A few feet below the sandstone, 
 coal B is represented by a six -inch band of impure coal at an eleva- 
 tion of about one hundred feet above the river. Ascending Huggin's 
 branch in a westerly direction, the same beds are again observed, but 
 at a much lower level, and the black shale at the base of the upper 
 group here makes its appearance. Near the head of the branch, 
 about a mile from its mouth, at Huggin's bank, a characteristic sec- 
 tion of the Lonsdale coal, or coal C, is found, (Section 2, Township 
 78, Range 30, Guthrie county.) The coal is two feet thick, and is 
 overlaid by the dark shale which presents its usual varied fauna. 
 
 About three miles above Fee's, at Duck's Mill, a fine section of 
 strata appears in the bluffs upon either side of the Middle Raccoon, 
 exhibiting in detail the upper portion of the middle group, and in 
 the tops of the bluffs northwest of the mills, coal C is obscurely 
 exposed. The lower black shale of the upper group is finely 
 developed at this locality, but no coal is associated with it. Ten to 
 fifteen feet below this shale coal B occurs, varying from four to ten 
 inches in thickness, as may be seen in the bluff above the mills. 
 
 In the vicinity of Tarn's mills, one or two miles above Duck's 
 
 mills, numerous exposures are met with in the main identical with 
 
 those just discovered. In the hillside near the mills, coal B outcrops 
 
 at an elevation of forty - five feet above the river, and is represented 
 
 by a six inch layer of rotten coal. The sandstone overlying the 
 
 coal is well developed, being some ten feet thick. Three or four feet 
 
 above the sandstone, the lower black shale of the upper group, capped 
 
 by its argillaceous cap -rock, is also well shown. But no signs of 
 
 the presence of coal C were detected at this locality. A mile north of 
 
 of the mills, on Hook's branch coal B affords a handsome layer of coal 
 
 eight inches thick. Descending this picturesque little dell, the 
 
 argillaceous limestone layers of the upper part of the middle 
 
 group are successively passed over, affording a plentiful harvest of 
 
 fossils; and toward its entrance the arenaceous beds of the lower 
 
 portion oif the group are met with. At this point the Middle Raccoon 
 2i 
 
186 REPORT OF STATE GEOLOGIST. 
 
 abruptly bends westward, and half a mile above the branch, on 
 the north side of the river, a high bluff gives an imperfect section of 
 the same beds above described. Ninety feet above the water the 
 black shales of the upper group appear at the surface, and eight feet 
 below this bed the sandstone which overlies coal B outcrops. The 
 elevation of the above horizons at this exposure, compared with 
 their level above the river at the mills, shows a westerly uprising of 
 the strata at the rate of about thirty - five feet to the mile. A few 
 hundred 'yards above the last mentioned exposure, coal A has been 
 brought to view above the water level. This bed is six to ten inches 
 thick, and capped by a massive sheet of dark calcareous, fossiliferous 
 shales twenty inches thick, above which twelve to fifteen feet of blue 
 clays are exposed. The whole aspect of this horizon at this locality 
 is so unlike its usual condition, that we would be at a loss to 
 determine its stratigraphical position under less fortunate circum- 
 stances. ' 
 
 In the vicinity of Panora, Guthrie County, the lower group of the 
 middle coal is well exposed, afibrding at several localities interesting 
 sections of coal A. At Brumbaugh's Mill, and in the vicinity of 
 the Panora Woolen Mills, the coal is ten to fourteen inches thick, 
 and of good quality. The cap -rock here is more regular than at 
 many localities, and gives a self-supporting roof to the entries, 
 which renders the working of the coal economical and remunerative. 
 The principal bants are Knowlton's, Frazier's, Wilson's and 
 Wasson's. At the latter bank, the uppermost layers of the lower 
 group are exposed in the ravine above the coal -bank, and in the 
 bottoms near at hand a shaft has penetrated the underlying clays 
 and sandstone, to the depth of forty feet below coal A, which I 
 hardly think has yet reached the heavy deposit of sandstone over- 
 lying the Redfield coal-bed. At the Panora Mills the same 
 horizons are exhibited, but here presenting some striking modifica- 
 tions. The elevation of the coal above the river level is about the 
 same at all the localities — twenty to twenty -five feet — which 
 indicates a gentle rise of the strata as we ascend the stream north- 
 westerly. Messrs. Hanyan and Nichols, at the latter locality, have 
 caused a shaft to be sunk in the bed of the river, which encountered 
 the same beds noted in the shaft at Wasson's bank, a mile and a half 
 
REPORT OF STATE GEOLOGIST. 
 
 187 
 
 below. Coal A, also outcrops in a ravine near Panora Mills, but the 
 coal is reduced to a two- inch seam. Above the coal, massive beds 
 of sandstone and shales occur, which are seen to advantage opposite 
 the mills. Should the strata continue to rise as we ascend the 
 valley, the upper beds of the lower coal - measures would be brought 
 to the surface a few miles above Panora. Indeed, this seems to be 
 really the case. 
 
 Some miles northwest of Panora, at Shaw's bank, a coal - bed has 
 been opened in the river bank but little above low - water mark. 
 The entry was closed with rubbish, precluding any actual examina- 
 tions, and in consequence only the most meagre and unsatisfactory 
 data were gained respecting the physical characters of the bed and 
 its stratigraphical positionf Three miles above Shaw's, on Spring 
 run, a coal - bed has been opened on lands belonging to Mr. John 
 Clark. The bank, however, was concealed by the debris from the 
 disintegrating sandstone which immediately overlies the coal. Still 
 higher up the valley, in the northern part of Guthrie County, and 
 in Carroll County, sandstones and clays are seen in many of the 
 bluffs, which frequently give exposures of an hundred feet in hight. . 
 Here and there, thin, interrupted carbonaceous bands occur in the 
 ferruginous grits and clays, and thin sheets of gravel are interstrati- 
 fied with the finer materials. 
 
 At Mount's coal -bank, seven miles below Raccoon Rapids, (sec- 
 tion twenty - eight, township eighty - one, range thirty - two, Guthrie 
 County) a one - foot bed of coal has been opened, overlaid by black, 
 fossiliferous shales, and light - colored clays with concretionary band 
 at top, upon which rests a soft sand deposit. And three miles and 
 a half above (section twenty -four, township eighty -one, range 
 thirty - three), apparently the same bed shows itself in the right 
 bank of the Middle Raccoon, characterized by the same shales and 
 organisms found at Mount's bank. There are other coal -banks in 
 this vicinity, which are doubtless referable to the same bed. 
 
 On Musquito creek, five miles east of Panora, at Howell's bank, 
 coal A is again met with, affording a twelve -inch bed, and agreeing 
 in all essentials with the banks near Panora, although'the bed at this 
 locality is high above the level of its outcrop on the Middle Raccoon. 
 
 The North Raccoon river passes nearly through the middle of Dallas 
 
238 RE POET OF STATE GEOLOGIST. 
 
 county in a northerly and southerly course, cutting across the middle 
 coal - measures nearly at right angles to the northern border trend of 
 this series. Ascending the valley from its coniluence with the South 
 Raccoon, the strata ascend or uprise to the northward at a much 
 more rapid rate than the fall of the stream in the opposite direction; 
 and reaching a point a few miles north of Adel, the most northerly 
 exposures of the lower members of the middle coal appear in the 
 ravines high above the river. Beyond the borders of the middle 
 series, horizons are encountered which present a marked contrast 
 to the strata found along the lower course of the stream, in some 
 respects recalling the beds on the Middle Raccoon above Panora. 
 
 One or two miles east of Adel, on Hickory and Miller's branches, 
 the upper beds of the middle group are finely exhibited. On Hick- 
 ory branch the upper sandstone of the middle group furnishes a very 
 good freestone, which is extensively quarried for building purposes. 
 Just above this bed, at one or two places, the same black shale of 
 the upper group is imperfectly exposed ; and four feet below the 
 sandstone a thin carbonaceous band appears, which is the represen- 
 tative of coal B. In the section on Miller's branch the same beds 
 are displayed, and in the lower portion of the bluff a local develop- 
 ment of .black shale is found, but which is not a reliable horizon. A 
 short distance north of Adel, on Butler's branch, at the base of a 
 low bluff composed of sandy shales and sandstone, a twelve -inch 
 bed of coal is said to occur. 
 
 At Chaney's coal- bank, four miles north of Adel, coal A appears, 
 which is here twelve inches thick, overlaid by the claj^s and thin,fos- 
 siliferous limestone layers which form the top of the lower group. 
 Lower down the ravine a still lower bed of coal outcrops in the banks 
 of the stream, which probably belongs to the lower coal - measures. 
 
 North of Chaney's the middle coal-measures have disappeared 
 and, although exposures of clay and sandstone a;re not unfrequent, 
 no coal is again met with, to my knowledge, before reaching the 
 southern border of Green county. On Brown's branch, seven miles 
 below Rippey, Green county, a ten- inch bed of coal makes its 
 appearance, and in the river bank near the mouth of the branch, 
 an eighteen -inch coal-bed is said to occur, which, however, is 
 only exposed at low water. Two and a half miles below Rippey, 
 
REPORT OF STATE GEOLOGIST. Jgg 
 
 at Bussy's bank, an eighteen - inch coal - bed is mined, which bears 
 a close resemblance to the upper coal-bed on Polecat creek, near 
 Boonsboro, on the Des Moines. 
 
 The northern limits of the middle coal-measures may be defined 
 by a line passing through the middle of the north half of Guthrie 
 and Dallas counties, in an east -and- west direction, nearly to the 
 Des Moines river, thence trending southeast through Dallas, Polk, 
 and into Warren county, nearly parallel with the course of the Des 
 Moines, as far as it has been traced. To the north of this line the 
 lower coal - measures appear at the surface, and stretch northward 
 into Green and Carroll counties. The northern boundary of the 
 upper coal - measures, in this part of the State, is parallel with that 
 of the middle series, and is definitely defined by the divide which 
 separates the Raccoon rivers from the Three River district to the 
 south. Therefore, the middle coal - measures occupy a belt of coun- 
 try about fifteen miles wide and extending east and west forty - five 
 miles or more. 
 
 It has been demonstrated that the middle and upper coal - measures 
 possess no thick beds of coal. Although coal occurs in these upper 
 measures, the beds are thin, and it is only where they are locally 
 thickened, as at Marshall's bank in Guthrie, that they present good, 
 workable beds. However, the upper bed of the middle coal- 
 measures is very regular, with an average thickness of twenty inches. 
 Wherever it is found in the country of the South Raccoon, it can be 
 easily mined, and is, probably, the best bed in the two upper divisions 
 of the coal-measures. It doubtless can be reached by boring, at 
 many places to the southward of Lonsdale's bank in Guthrie county, 
 but to the east and north and westward it has been swept ajway by 
 the denuding agencies which exposed the lower groups of the middle 
 coal-measures, and, still farther to the northward, revealed the 
 upper portion of the lower coal - measures. In the counties imme- 
 diately to the southward of Guthrie, this bed is buried beneath the 
 limestones and shales of the upper coal - measures. 
 
 The lower coal-measures are the great repository of mineral 
 fuel, and to this series we must look for the main supply of coal 
 in the State. Although an extensive tract of country bordering 
 upon the Des Moines is underlaid by the lower coal-measures, the 
 
3^90 REPORT OF STATE GEOLOGIST. 
 
 the general southwesterly inclination of the strata, in connection 
 with the ascent of the surface in the same direction, has carried this 
 productive series beneath the middle and upper coal - measures, and, 
 with the exception of the Redfield uplift, they are wholly lost to 
 view in the southwestern portion of the State. At present we have 
 no reason to believe that the lower measures are any less productive 
 in their southwestern extension than they are along the Des Moines. 
 In the valley of the Raccoon and on' the lower courses of the South 
 and Middle Raccoon rivers, the horizon of the Des Moines coal, or 
 upper bed of the lower coal - measures, may be reached by boring at 
 variable depths, depending upon the stratigraphical position of the 
 locality at which it is desired to seek this bed. It is not improbable 
 that below Redfield this bed may be found above the level of the 
 South Raccoon, or within a limited distance beneath the surfa,ce of 
 the valley. But to the eastward it gradually sinks deeper and deeper 
 beneath the level of the streams until reaching the mouth of Bulger 
 creek, at which point it probably lies at a depth of one hundred and 
 fifty feet, or thereabout, below the river. Between the Bulger and 
 the Des Moines, the strata slowly rise eastward, which possibly brings 
 this' coal horizon within sixty to eighty feet of the level of the Rac- 
 coon river at the mouth of Sugar creek. And ten miles in a direct 
 course east of Sugar creek this bed gains the surface in the banks 
 of the Des Moines river at the city of Des Moines. But it must be 
 borne in mind that all beds of coal are more or less variable in 
 thickness, particularly if they extend over large areas; therefore, the 
 above estimates indicate the horizon of the coal rather than the 
 actually known presence of the fully- developed bed. It is known 
 that below the Des Moines coal all the heaviest beds of the lower 
 coal - measures are found. Dr. White has described many of these 
 coal -banks, and they compare favorably in all respects with the coal 
 of corresponding horizons of other States. 
 
GEOLOGY OF THE MIDDLE REGION OF WESTERN IOWA. 
 
 The country embraced in the three central tiers of counties lying 
 between the Missouri and Des Moines rivers, possesses natural 
 features generally common to the western half of the State. How- 
 ever, on a more careful examination of the ground, both with refer- 
 ence to the elimination of its topographical as well as its geological 
 features, we find certain peculiarities, on the one hand, common to 
 both the northern and southern portions of this region, which, when 
 viewed at the extreme opposite points upon the east and west, 
 present little in common with one another. But in this intermediate 
 region the more distinctive surface features which characterize the 
 extremes give way, and the result is a blending, or rather a toning 
 down, so to speak, of the more prominent and widely diverse topo- 
 graphical features which are no where to be found more beautifully 
 displayed than in Western Iowa. 
 
 The streams of the western watershed have a wes'terly flow, and 
 seek their outlet in the Missouri. In this part of the State the streams 
 take their rise in the great plateau which separates the waters of the 
 Mississippi from those of the Missouri. In Shelby, Audubon, and 
 the southern portions of Carroll and Crawford counties, several 
 streams take their rise, which flowing southward, reach the Missouri 
 within the borders of the State of Missouri. Of these may be men- 
 tioned the three principal branches of the Nishnabotany and 
 Whitted's creek,* Musquito, Keg and Cooper creeks. To the north- 
 ward, the Boyer, Willow and Soldier rise in Sac and Ida counties, 
 
 *'Wliitte(J creek rises in Carroll county, and flowing southwesterly falls into the 
 West Nishnabotany a few miles below Harlan, in bhelby county. 1 could not 
 learn that this beautiful little stream possessed a name, and hence I have sug- 
 gested the above name in honor of Mr. F. J. WniTTBDof Exira, Audubon county, 
 who was one of the first surveyors in this part of the country, and whose name 
 has been thoroughly identified with the progress and best interests of these coun- 
 ties from their earliest settlement to the present time. 
 
192 REPORT OF STATE GEOLOGIST. 
 
 and passing diagonally through Crawford, Harrison and Monona 
 counties reach the Missouri along the middle border of the State. 
 The Little Sioux and its principal tributaries, the West Fork and 
 Maple river, head in the northern part of the State, and drain the 
 fine region embraced in Ida, Woodbury, and the western portion of 
 Monona counties. Along their upper course the streams become 
 mere drainage depressions, though their character as such is always 
 distinctly marked. Upon the head-waters of the numerous small rivers 
 and creeks which traverse this portion of the western watershed, we 
 do not find the streams taking their rise in lakelets, as in the country 
 east of the grand divide ; on the contrary, they are divided into a 
 multitude of drainage channels which mark their delicate ramifica- 
 tions to the very crest of the watershed between the two river 
 systems, and by this means a system of the most complete drainage 
 is effected. These upper ramifications have been called " draws," 
 and not inappropriately, as their beds are not usually occupied by a 
 continuous channel, for they are seldom fed by springs ; but their 
 chief use is to collect the surface waters, and hence it is only during 
 the spring and autumn seasons that their beds are flooded. In the 
 summer their waters shrink into little dark pools, and their beds are 
 carpeted by a tall, nutritious herbage, quite in contrast to the lower 
 grasses of the surrounding prairies. These streams of green herbage 
 follow all the graceful meanderings of the channels to their very 
 sources, and impart a refreshing feature to the prairie landscape. 
 
 The Raccoon river system is tributary to the Des Moines, and is 
 the most considerable, both as regards the size of the streams and 
 the area which they drain, that occupies the country between the 
 Des Moines and the grand- divide upon the east slope. The courses 
 of the four principal branches, the North, Middle, Bushy Fork and 
 South Raccoon, are nearly at right angles to those of the streams 
 previously mentioned upon the western watershed and parallel with 
 the divide. All, with the exception of the North Raccoon, take their 
 rise in Guthrie and Carroll counties ; while the latter passes through 
 the entire length of Sac county, to the north, and heads in Buena 
 Vista and Pocahontas counties. The peculiarities of the drainage 
 upon the two watersheds are widely different; upon the western, we 
 meet with a multitude of small branches, while in the country east 
 
REPORT OF STATE GEOLOGIST. I93 
 
 of the great divide tlie larger streams possess comparatively few 
 small affluents. Before we go further, let us make a brief examina- 
 tion of the deposits in which the varied topographical features of the 
 region are moulded, and which will enable us the better to under- 
 stand the origin of the present appearance of the surface in this 
 section of the State. The superficial deposits which occur in the 
 western part of the State are the drift and bluff. In the country 
 between the grand divide and the Des Moines, the drift is largely 
 developed, consisting of blue clays, and yellow, sandy clays, which 
 latter is usually spread over the greater part of the surface. Upon 
 the west slope the drift rapidly diminishes in thickness, and is over- 
 laid by the peculiar yellow clays of the bluff. This latter deposit 
 reaches its greatest development on the western borders of the 
 State, when it attains a somewhat variable thickness, probably at 
 many localities not less than two hundred feet. The fine nature of 
 the material which comprises the bluff, seems to furnish conclu- 
 sive evidence of its lacustrine origin. On the other hand, the 
 coarse materials which enter so largely into the composition of 
 the drift, were deposited at the bottom of the great fresh - water sea 
 at the close of the glacial period. The bluff clays abut upon the 
 Missouri bottoms in ranges of steep bluffs, which, when visited from 
 the valley, or looking either up or down their course from some 
 eminence, it requires but little effort on the part of the imagination 
 t,o transform the whole landscape into one of lofty mountain ranges 
 and great plain. Although in the region of the drift upon the east 
 watershed we do not meet with such bold, exaggerated surface fea- 
 tures ; nevertheless, that section possesses its strongly marked pecu- 
 liarities, which furnish a striking contrast to the country bordering 
 the Missouri. 
 
 Descending the water - courses towards their confluence with the 
 Missouri, the valleys gradually descend, and narrow intervals rise 
 from the margins of the streams to the gentle border slopes of the 
 uplands. Along their lower reaches, the streams are eroded to the 
 depth of two hundred feet and upward, and their exit from the 
 uplands is guarded by the massive hights of the great lacustrine 
 deposit. Between these streams the surface is rolling, though sel- 
 dom broken. ■ The streams themselves are bordered by steep, grassy 
 25 
 
3^94 REPORT OF STATE GEOLOGIST. 
 
 banks, and their beds, -with few exceptions, are filled with quicksands 
 or equally treacherous mire. The uplands are remarkably free from 
 boggy land, and " sloughs " are encountered only in the low bottoms 
 along the streams. In the immediate neighborhood of the Missouri 
 bottoms, where the uplands are abruptly terminated, the surface is 
 usually broken, and the bluffs ar.e penetrated by deep, narrow 
 ravines, shaded by dense forest growths, whose existence one little 
 suspects until their canon -like beds are overlooked from the ridges 
 above. The Missouri bottoms form one of the most remarkable 
 peculiarities of the West. They extend the entire length of the 
 State, and are more or less variable in width. In Harrison County, 
 between the Boyer and Little Sioux, the bottoms have a width of 
 eight miles ; and in Monona and Woodbury Counties they crowd 
 inland a distance of twelve miles or more, and the bluffs which 
 abruptly define the eastern margin, do not again approach the river 
 until within a few miles of Sioux City, at Floyd's Bluff, where they 
 form a conspicuous headland overlooking the turbid waters of the 
 Missouri for miles. The bottoms rise in low benches, which, in 
 form, have all the characteristics of true terraces, although they are 
 but little elevated above the general level. These benches, however, 
 are composed of exceedingly fine materials, and in this respect they 
 differ greatly from the terraces, or " second bottoms," along the 
 streams of the Mississippi watershed. Like true terraces, they are 
 most elevated along their outer margins, and slope inland, giving rise 
 to the little lakes and channels which not unfrequently skirt the base 
 of the bluffs and meander through the bottoms, affording a natural 
 drainage. Throughout the entire extent of the bottoms, the soil is 
 of unsurpassed fertility, and the day is not distant when this 
 immense tract of alluvial lands will hold a foremost place in the 
 agricultural interests of the West. 
 
 As has been previously mentioned, the greatest development of 
 the bluff deposit occurs in the Missouri river bluffs, where it ranges 
 from one hundred to two hundred feet in thickness. To the north- 
 ward, however, the deposit gradually diminishes in thickness, and in 
 the neighborhood of Sioux City, it is reduced to half its "maximum thick- 
 ness in the counties to the southward. It crowns all the cretaceous 
 hills, and gives to the region about, that peculiar character of 
 
EEPORT OF STATE GEOLOGIST. ^95 
 
 topography pertaining to this deposit. Indeed so markedly is this 
 manifest that the presence of the cretaceous formation can hardly be 
 said to have taken more than an insignificant part in giving the 
 country its present configuration. 
 
 Underlyiiig the blufi" material along the Missouri valley, at many 
 localities, we find a thin layer of sand, with pebbles and boulders, 
 distinctly arranged in layers ; and which, in turn is underlaid by the 
 clays of true Drift epoch. But more frequently the thin stratum of 
 modified drift material is found resting immediately upon the rocky 
 strata, with no intervening clays ; and sometimes even the gravel - bed 
 disappears, and the base of the bluff comes in immediate contact with 
 the consolidated rocks, as observed in the environs of Sioux City. 
 However, if we ascend any of the valleys of the larger inland - streams, 
 as the Little Sioux and the Boyer, as we recede from the Missouri 
 river bluffs eastwafrd, we shall very soon witness a gradual increase 
 in the development of the gravel - beds ; and soon low outliers 
 protruding from beneath the bluff deposits, will add an unusual 
 element to the landscape, and however inconspicuous these bunches 
 may be they are always sure to arrest the eye and gain our interest, 
 if no other than this very obscurity. On the Little Sioux the gravel- 
 beds are found fifty feet above the stream, overtopped by twice that 
 thickness of bluff. And at Dennison, at the confluence of the two 
 main branches of the Boyer, similar exposures are found, from which 
 is obtained the gravel for the manufacture of the concrete brick at 
 that place. Also near Dennison, on Judge Bassett's farm, certain 
 layers of these deposits are found sufiBciently cemented, to 
 answer for laying up in rough walls. Generally speaking, however, 
 the gravel deposits are too wasted to have more than a slight influence 
 in modifying the nature of the soil, which is still decidedly of bluff 
 origin. 
 
 In the country bordering upon the Nishnabotanys, the bluff pre- 
 sents some of its most characteristic features. The divides are 
 massive and rounded in outline, and descending into the valleys by 
 those long, graceful slopes, it is not unfrequently difiScult to draw 
 the demarkation between bottom - land and upland. But on approach- 
 ing the grand divide, the drift is frequently found high in the slopes, 
 
J9g REPORT OF STATE GEOLOGIST. 
 
 the line of its outcrops studded with boulders, and giving a sort of 
 angularity to the topography which is wholly foreign to the bluff. 
 
 Ascending the east branch of the Boyer, the bluff clays continue 
 to compose the great bulk of the uplands, and sweeping over the 
 watershed in Carroll and Audubon counties, burying deep beneath 
 its mass the underlying deposits, it forms a heavy capping upon the 
 divide between the South Raccoon and Brushy Fork, and tips the 
 crest of the ridge between the latter stream and Middle Raccoon, 
 upon the east watershed. At this point, which is the eastern border of 
 the bluflf in this section, the topography assumes a totally different 
 aspect, and ia many respects essentially peculiar to that section of 
 the country drained by the Raccoon rivers. 
 
 But to return to the west watershed, we will next ascend the main 
 branch of the Boyer. Starting from Denison, our route thence to 
 the northeast corner of Crawford county traverses the beautiful up- 
 land upon the east side of the Boyer, and parallel with its course. 
 The bluff- clays continue to impart to the soil and to the surface- 
 outline of the country its well - marked peculiarities until we have 
 passed beyond the borders of Crawford and entered Sac county. 
 Here the country becomes changed. The surface, instead of pre- 
 senting those smooth, graceful slopes and finely - comminuted soil 
 everywhere met with and common to the bluff wherever it exists, 
 stretches to the northeastward in a barely perceptibly - rising plain, 
 traversed by long files of low wave - like ridges or swells, whose cretts 
 are paved with boulders and the slopes strewn with gravel. We have 
 hardly missed the presence of the familiar lacustrine deposits ere we 
 find ourselves environed by entirely different geological and topo- 
 graphical phases. We are again standing upon the great divide, 
 overlooking almost an immensity of prairie, the horizon to the east, 
 west and south presenting a continuity as unbroken as that at sea, 
 but which to the northward is interrupted by the heavy drift- ridges 
 whose outlines are sharply defined against the background of deep- 
 blue sky at that quarter. Every step of the way thence to Wall 
 Lake exhibits the uncovered drift deposits ; and reaching the bluffs 
 overlooking the North Raccoon at Grant City, and throughout its 
 course below, well - defined terraces, or " second bottoms," border 
 
REPORT OF STATE GEOLOGIST. 297 
 
 either margin of the valley, which greatly enhance the scenic effect 
 and afford beautiful rural situations. 
 
 The dividing ridge in this region has a generally northwest and 
 southeast direction. Between Audubon and Guthrie, and in Carroll 
 county, it forms a sinuous ridge, from the crest of which the drain- 
 age " draws " descend upon either slope, on the one hand to join 
 the numerous affluents of the Nishnabotany and the Boyer, and 
 upon the other to augment the tributaries of the Raccoon rivers. 
 But as we pass along the divide to the northward, in the northern 
 portion of Carroll county, the drainage of the two watersheds is 
 interlocked, so to speak, by the head- waters of the Middle Eaccoon 
 and the east branch of the Boyer ; and here the divide is as sharply 
 defined as the ridge of a gable roof. Further to the north the ridge 
 expands into a gently undulating plateau, which is traversed by low 
 ridges of drift, producing an entirely different configuration from 
 what it possesses to tho southward. These ridges are composed of 
 the loose material of the drift, and form the highest land in this part 
 of the State, with an elevation above the level of the sea, probably, 
 of not less than fifteen hundred feet. The broad, shallow depres- 
 sion intervening between the knobs or ridges of drift, possess'a rich, 
 black, gravelly soil, which differs in many respects, excepting in fer- 
 tility, from the soils of the west watersheds. It will have been already 
 seen that the difference in the soils of the east and west watersheds 
 is due to tho difference in the nature of the immediately underlying 
 deposits in the two sections. Wherever the bluff clays are found, a 
 fine, light - colored, durable soil is produced, which is particularly 
 well adapted to the growing of cereals ; and in the region of the 
 drift, east of the dividing ridge, the soil is of a loamy nature, though 
 possessing many varieties, susceptible of early tillage, and returning 
 abundant harvests to thorough cultivation. 
 
 The Raccoon rivers are deeply excavated into the drift and coal- 
 measures ; their valleys are narrow and bordered by steep bluff 
 ascents, and usually terraced. But along that part of the courses , 
 of the South Raccoon and Bushy Fork bordered by the bluff deposits, 
 either these "second bottoms" are wholly obliterated or only obscurely 
 displayed — a peculiarity, as heretofore observed, common to these 
 deposits wherever they are found associated. The moment, however, 
 
198 KEPORT OF STATE GEOLOGIST. 
 
 the streams pass beyond the influence of the bluiF, the benches which 
 rise step -like upon the sides of their valleys assume definite out- 
 lines, and hence continue to impart to the valleys a prominent and 
 pleasing feature in their formation and appearance. The uplands 
 are level, or but gently undulating, and instead of sweeping down 
 into the valleys by more or less steep, smooth slopes, as is the 
 case with the uplands of the bluflf country, they are always 
 abruptly terminated upon the brink overlooking the valleys from 
 a hight of one hundred to two hundred feet. The quality of the 
 soil in the valleys proper varies according to the location. Immedi- 
 ately bordering the margins of the streams, the low intervals occur, 
 which are made of sediments, sand, &c., the deposit of the freshets. 
 The lower terrace is usually enveloped in a fine, loamy covering, of 
 remarkable fertility. The earlier or higher terraces, on the con- 
 trary, are composed of coarse, rearranged materials derived from 
 the disintegration or wearing away of the drift which once filled 
 these valleys — for the valleys are evidently of very remote origin, 
 extending far back into the past to a time prior to the glacial or ice 
 period. These higher benches possess the warm, gravelly soil, so 
 common in the valleys of many of our rivers which are tributary to 
 the Mississippi. In the valley of the North Raccoon, below Granite 
 City, in the counties of Calhoun, Carroll, Green and Dallas, and 
 also in the valleys of the South and Middle Raccoons, the terrace 
 formations may be advantageously studied. But they are seen only 
 in the valley of the North Raccoon, as at Adel, near Mr. Gibson's, 
 above New Jefi"erson, and in the vicinity of Morlan's, Calhoun, 
 county, where they present some of their most conspicuous and 
 diverse peculiarities. \ 
 
 In connection with the terraces, interesting spring phenom- 
 ena are frequently observed, which have attracted considerable 
 notice. In Greene, Carroll and Calhoun counties it is not uncom- 
 mon to meet with limpid streamlets trickling down the slopes 
 toward the river, and sometimes they have formed for themselves 
 deep channels in the loose material of the surface over which they 
 flow. Tracing these little streamlets to their sources, they are 
 invariably found to issue from the gravel - bed immediately at the 
 point of junction with the impervious blue clays of unmodified drift. 
 
REPORT OF STATE GEOLOGIST. ]^9g 
 
 It is only at those localities where the sheet of gravel has been inter- 
 rupted in its descent to the lower levels of the valley, bringing to 
 the surface in its stead (it may be but a narrow band) the underlying 
 clays of the drift, that natural springs may be expected. Many 
 times the springs issue almost at the _brow of the bluffs, and upon 
 the steep slopes peaty deposits are in process of formation from the 
 partial decomposition of the luxuriant herbage growing in the wet 
 spots. 
 
 Wells of excellent water may be obtained at almost any point by 
 sinking a shaft down through the modified materials to the upper 
 surface of the drift clays, and usually at a moderate depth from the 
 surface of the ground. In the country of the west watershed, rills of 
 water are not obtained at so short a distance below the surface ; there 
 the great thickness of the bluff clays must be penetrated before the 
 lower, water - saturated gravel bed is reached. This would prove' a 
 serious disadvantage in that section were it not that the bluff material 
 possesses that tenacious quality which enables excavations to be made 
 at any depth in its mass without incurring the risks of slipping or 
 falling in or the expense of curbing. 
 
 The distribution of forests upon both watersheds seems to have been 
 governed by the influences. The annual fires which sweep the prairies 
 of the interior, unchecked, have doubtless had most to do in pre- 
 venting the general growth of forests in this region. The groves are 
 usually found in such situations as afford thcm the best natural pro- 
 tection from the devastations of the fires. These situations are 
 variously located, but usually the densest timbered lands are confined 
 to the lower bottoms bordering the streams and in the deep gullies 
 which penetrate the uplfinds. Considerable bodies of timber skirt 
 the Missouri bottoms, but between this belt and the foot of the bluffs 
 the level stretch of the bottoms is interspersed only at long intervals 
 by lone cottonwoods or clumps of willow. Upon many of the streams of 
 the western watershed various belts or little groves are not unfrequent, 
 and they contribute the most redeeming features to the landscape. 
 Groves are not always confined to the river margins, however, for it 
 is not a rare occurrence to meet with them upon the upland ridges, 
 though in these situations their gnarled, charred trunks bear painful 
 evidence of their struggles with the fires. A few miles north of 
 
200 REPORT OF STATE GEOLOGIST. 
 
 Exira, in Audubon, a considerable tract of the upland is covered 
 with a scattered growth of oaks and underbrush. And in Crawford, 
 Harrison and Monona counties, many of the divides are covered with 
 low, bushy oaks, which spring from roots as large as those of the 
 mature forest tree. Since the settlement of this part of the State,. 
 fine groves of young timber have grown up where fifteen years ago 
 the luxuriant herbage of the prairies was the only vegetation. In 
 the northwest portion of Shelby county there is a large body of 
 forests on Mill creek and its affluents, which is said to contain about 
 ten thousand acres; it is the largest body of timber in this region. 
 Upon the east watershed the valleys of the Raccoon rivers and their 
 affluents afibrd considerable bodies of timber — enough, indeed, to 
 supply the demand for many years to come. Upon the upland in this 
 portion of the State handsome groves planted about the farms already 
 break the continuity of the horizon - like islands ; and if farmers 
 would give more attention to the planting of artificial groves, in a 
 few years the country would wear a very ^diiferent and far more 
 inviting appearance. 
 
 Fruit - trees are said to thrive throughout this section of the State; 
 the great difficulty to be encountered in their cultivation, is to check 
 the rapidity of growth which is so fatal to the hardiness of the 
 yourig tree. It must be borne in mind, however, that there are few 
 localities in the thirteen counties of this district which have been 
 settled for a longer period than twelve to fifteen years ; and expe- 
 rience teaches that the introduction of fruit - trees into a new country 
 is almost always attended with many discouragements. Now, that 
 nurseries have been established in various parts of the State, "and 
 the trees acclimated and accustomed to the soil, in a few years we 
 may reasonably hope to see as fine orchards upon our prairies as are 
 to be met with in any of the older States in the same latitude. 
 
 Little attention has been given to the introduction of the cultivated 
 grasses. But there can be no doubt, in view of the experience of the 
 older settled portions of the State, as to the practicability of covert- 
 ing immense tracts into the finest meadows in the world. To - day, 
 however, the whole prairie is a common, natural pasturage and 
 meadow. Upland and valley alike are clothed with nutritious 
 herbage, affording a boundless range; and rivulets, brooks and 
 
REPORT OF STATE GEOLOGIST. 201 
 
 rivers furnish a never failing supply of water. In fine, there is 
 diversity enough to please all tastes and suit all interests. There is 
 a variety of soils, but the same grains may be produced from any of 
 them with almost equally remunerative results. And now, that 
 these counties will soon enjoy the facilities afforded by three main 
 railway lines which traverse their territory east and west, this 
 section of our State will possess advantages second to those of no 
 similar district, and open to enterprise which it is so capable profit- 
 ably to sustain. 
 
 26 
 
REPORT 
 
 GUSTAVUS HINRICHS 
 
 STATE CHEMIST. 
 
REPORT OF CHEMIST. 
 
 To Dk. C. a. White, State Oeologiat: 
 
 Sir — The accompanying Report contains the principal results of my chem- 
 ical work for the survey. It will be most convenient to divide this Report into 
 the following chapters, according to the subjects treated of: 
 1. Chbiiical Report on the Fuel op Iowa. 
 II. CnEMicAL Report on the Water and Rocks op Iowa. 
 III. On the Valuation, Composition and Proximate Analysis op Iowa 
 
 Coals. 
 IV. On thk Mineralogy op Iowa. 
 
 GUSTAVUS HINRIOHS. 
 Iowa City, February 24, 1868. 
 
CHEMICAL REPORT ON THE FUEL OF IOWA. 
 
 CHAPTER I. 
 
 In this chapter the chemical composition, physical properties and 
 heat - giving value of our Iowa fuel will be given, particularly in 
 regard to coal. 
 
 The fertile soil of the State can furnish an abundance of digestible 
 fuel, food for the stomachs of the present population and several 
 millions more. Below the surface of this soil there is an almost 
 inexhaustible supply of very good indigestible fuel, food for the iron 
 stomachs of hundreds of steam boilers, which one day will be busy 
 in this State, doing the hard work of millions of hands; the joint 
 labor of the human hands, supported by the product of the soil, and 
 of the iron hands, fed by the fuel from below the soil; this is the 
 measure of the future wealth of the State. Hence the prominence 
 given to the geological and chemical investigation of the fuel of the 
 State in the labors of the present Geological Survey of Iowa. 
 
 I. ON THE CLASSIFICATION OF FUEL. 
 
 Whenever any fuel is heated to a certain temperature, it will burn, 
 provided at the same time the air has free access. The result of this 
 combustion is a -two - fold one ; the material apparently disappears 
 (leaving only a small amount of ashes) and heat is produced at the 
 same time. In other words, the fuel has been changed into two 
 gaseous products, carbonic acid and water, and in this transforma- 
 tion heat was given off. 
 
 We burn the fuel merely in order to obtain this heat yet it can not 
 be set free except by converting the fuel into the above mentioned 
 two substances, carbonic acid gas and water. 
 
206 
 
 REPORT OF STATE GEOLOGIST. 
 
 These two substances form a considerable part of tbe atmos- 
 phere surrounding the globe, and every combustion increases this 
 amount. While thus the amount of combustible matter of fuels 
 is continually diminished by the increasing wahts of man, the 
 question naturally arises : can not these products of combustion 
 be re - converted into fuel ? Can not fuel be manufactured? No 
 doubt it can be done ; chemists have succeeded to decompose both 
 products above named, so as to reproduce combustibles. Even the 
 twelve per cent of pure carbon contained in our common limestone 
 can very readily be extracted from the same by chemical means. 
 But the power necessary for this purpose is heat, so that unless this 
 heat be obtained at a very low price, these chemical processes can 
 jiot be utilized in the arts, or fuel can not be manufactured. 
 
 Fortunately there is one source of heat costing nothing, that is 
 the heat of the sun. Fortunately there is one chemical apparatus, 
 costing nothing, but most eminently adapted to the work of 
 re - decomposing the products of combustion given to the air ; this 
 apparatus is the plant. Just as soon as but a leaflet is above 
 ground, the young plant under the power of the sun's ray. com- 
 mences its attack upon the products of combustion contained in 
 the air ; the result of this labor is vegetable matter, combustible, 
 and in proportion as the chemical work of the solar ray and atmos- 
 pheric air goes on in the cell of the plant, this increases continually. 
 It is this action which gives us our forests, our peat and our coal ! 
 
 Until heat can be obtained cheaper than the free all -reaching ray 
 of the sun and the raw -product can be had for less than nothing, the 
 present quotations of a liberal atmosphere-; until then fuel will not 
 be produced except as the result of vegetation. 
 
 Force being as indestructible as matter, we here discover the 
 origin of the heat produced by combustion. For since the heat of 
 the sun acting upon the carbonic acid and water in the air makes the 
 fuel, this latter when burning reproduces not only the former matter 
 (carbonic acid and water,) but also the force, heat. We may, there- 
 fore, say that the vegetable tissue is air woven by the sun's ray. 
 
 It may be well to notice that this circulation of force and matter 
 is perfect ; solar heat and the products of combustion produce the 
 combustible ; this latter in being burnt, re - produces both the 
 
REPORT OF STATE GEOLOGIST. 
 
 207 
 
 materials of which it was made, and the heat which wove these 
 materials together. 
 
 In burning a branch of last season's growth, we set free the sun- 
 beams of that season ; in burning a tree a thousand years old, we 
 set free the solar ray that came to our earth a thousand years ago ; 
 in burning coal, the product of a vegetation which flourished millions 
 of years ago, we liberate the beams of the sun which came to this 
 globe millions of years before the appearance of man. 
 
 All our fuel is undoubtedly of vegetable origin. But as vegetation 
 is of two tolerably distinct kinds, aquatic and terrestrial, the fuel 
 resulting must vary accordingly. The plants growing on the land 
 need a special, firm texture to support their own weight ; those 
 growing in the water are almost completely held up by the buoyancy 
 of the liquid, and are therefore devoid of woody fiber. As the 
 forests on the land, so dominates the sea - weeds among the plants of 
 the deep ; they arje often hundreds of feet in length, and of consider- 
 able thickness. 
 
 Plants may be used as fuel immediately after being cut down 
 (our fire- wood), or they may have been buried in the sea or among 
 the rocks for a greater or less length of time (fossil). Accordingly 
 we obtain the following general classification of luel : 
 
 PLANTS. 
 
 GHOWN ON. 
 
 NAMB. 
 
 AGE. 
 
 Land ■ plants 
 Land -plants 
 Land- plants 
 Sea -plants., 
 fcea- plants.. 
 
 Ury ground. 
 Dry ground. 
 Wet ground. 
 
 Trees iFresh. 
 
 Trees. 
 
 .Mosses, heather, etc. . 
 
 Sea - weeds 
 
 Sea -weeds . . ., 
 
 Fossil. 
 
 Fossil. 
 Fresh . 
 
 Wood 
 
 Lignite and brown coal . 
 
 Peat '. 
 
 Coal proper 
 
 Not much used 
 
 All of these varieties of fuel are found in Iowa, except Brown coal 
 or Lignite. 
 
 Just as well as our forests continually produce an increase of 
 wood, so we know our peat - bogs annually to add to the store of 
 peat ; and the immense regions of sea - weeds in the oceans prove 
 that coal also is continually being formed on our globe. This view 
 was but a few years ago advanced by the distinguished German 
 chemist, F. Mphr, of Bonn on the Rhine. In the course of my 
 investigation of the Iowa coals, I have discovered several facts which 
 
208 REPOKT OP STATE GEOLOGIST. 
 
 add considerably to the already overwhelming evidence brought for- 
 ward by the author of this theory. 
 
 We shall now consider the chemical composition of these various 
 fuels, indicating the exact place of our Iowa fuels in the series. 
 Thereafter we intend to show how the valuation or heating effect of 
 these fuels is determined. Finally, the results of the several 
 analyses of Iowa coals will be given by counties. 
 
 It may not be improper to give a short synopsis of the history of 
 the coal, particularly as this, after Mohr's labors, appears remarkably 
 simple, and also because our Iowa coal-field seems particularly 
 adapted to prove the correctness thereof. 
 
 In order to make this chapter of interest to the general reader, I 
 shall leave out everything of an abstruse nature ; but for the sake 
 of completeness, these matters will be given in a separate chapter. 
 
 n. ON THE COMPOSITION OE FUEL. 
 
 The chemical elements which constitute by far the greatest portion 
 of all fuel, are Carhon, Hydrogen, and Oxygen. 
 
 The first of these we have almost pure in charcoal; it burns 
 without producing any flame while producing a very high degree of 
 heat. The greater the proportion of carbon in any fuel, the deeper 
 black will be the color of the same, and the more intense will be the 
 heat produced by its combustion, but the less flame will result. 
 
 The second of these elements, hydrogen, is the very opposite; not 
 solid but a gas, and even the lightest body we know ; when burning 
 it is all flame, producing a great quantity but relatively not so high a 
 degree of heat, as carbon. Hydrogen constitutes one-ninth by weigKt 
 of water, about one- sixth by weight of common illuminating gas. 
 Hence the greater the per centage of hydrogen in any fuel, the more 
 flame when burning. That part of the burning fuel which is sufli- 
 ciently heated will decompose, giving off its hydrogen and some carbon, 
 as a gaseous substance, more or less like illuminating gas ; as soon 
 as this meets the air, supplied by means of proper draft, it will burn 
 constituting the flame of all these combustibles. 
 
 The third principal element of our fuels, oxygen, may be considered 
 an unproductive part of the fuel. When constituting a part of the 
 
REPORT OF STATE GEOLOGIST. 209 
 
 fuel, it costs a corre.iponding amount to us, while in the air we could 
 have it free of cost; and as the heat of combustion only results from 
 the carbon or hydrogen uniting with oxygen, it is furthermore 
 evident, that any oxygen united with these other elements in the fuel 
 prevents those parts thus already provided with oxygen from pro- 
 ducing any heat. A fuel is therefore so much the better the less the 
 amount of oxygen it contains. 
 
 Omitting for the present the consideration of those elements 
 present in small quantities, we may express the average composition 
 of the various fu<;ls, referred to one hundred carbon, in the following 
 figures : 
 
 FUEL -DRIED. 
 
 
 ^ 
 
 
 
 
 
 
 OJ 
 
 
 □ 
 
 bij 
 
 c 
 
 o 
 
 t~ 
 
 
 
 
 X 
 
 o 
 
 tr 
 
 ■^ 
 
 Wood 
 
 Peat 
 
 Lignite 
 
 Bituminous Coal. 
 Aiiiliracite 
 
 1 100, 
 
 i6 
 
 yo 
 
 a03 
 
 1 100] 
 
 10 
 
 601 
 
 170 
 
 lOOl 
 
 8, 
 
 30 
 
 138 
 
 100 
 
 7| 
 
 15 
 
 123 
 
 1 100 
 
 2' 
 
 5 
 
 107 
 
 The fuels abuodant ia Iowa are iu italics 
 
 According to the remarks just made, it will require much more 
 wood than coal to produce the same heating effect, on account of the 
 great proportion of oxygen in the former. The amount of hydrogen 
 corresponding to 100 carbon gives a fair representation of the 
 inflammability of the fuel. 
 
 The fuel, as commonly used, is not artificially dried, but contains 
 a greater or less amount of moisture. A portion of the heat devel- 
 oped by combustion of the fuel is therefore wasted in driving off the 
 moisture. All fuel, furthermore, contains a very noteworthy amount 
 of ashes, which also, in various ways, diminishes the effectiveness of 
 the fuel. Nor can we finally consider the fuel as merely constituted 
 of the above elements thoroughly mixed up, they are chemically 
 combined. To increase the difficulty still more, it has hitherto not 
 been possible to ascertain the exact way in which these elements are 
 combined. Tims it seems, that very little can be ascertained chem- 
 ically in regard to the exact value of the various fuels. 
 27 
 
210 REPORT OF STATE GEOLOGIST. 
 
 But Tvhen fuels are used for heating purposes, they are, as men- 
 tioned above, always more or less decomposed before they are totally 
 consumed. The heat in the fire - place decomposes the fuel into a 
 volatile and a non - volatile portion ; the former when burning con- 
 stitutes ihe flame, the latter when cooled constitutes the coke, (or, in 
 the case of wood, charcoal.) Hence, it is not at all the fuel as it is 
 thrown upon the grate that burns, but rather the products resulting 
 from the fuel when exposed to the heat of the fire - place. Although 
 we therefore may be ignorant of the exact arrangements of the 
 elements in the cold fuel, we may, nevertheless, be able to estimate 
 its heating eifects, if we succeed in ascertaining the products wherem 
 the fuel is decomposed previous to its actual combustion. 
 
 Now this is what the so - called proximate analysis of fuel attempts 
 to do. By exposing the fuel to heat, being careful to exclude the 
 air from it, we ascertain the amount of volatile matter in the fuel ; 
 this subtracted from the total weight taken, gives the per centage of 
 coke. By separate operations both the amouit of moisture and of 
 ashes is determined ; subtracting the former from the volatile, gives 
 the amount of volatile combustible matter, which I for brevity call 
 bitumen ; subtracting the per centage of ashes from that of the coke, 
 we obtain the amount of non - volatile combustible matter, which is 
 almost pure carbon, and therefore is called carbon. By means of an 
 extensive series of experiments, I have succeeded in psrfecting this 
 method of analysis to be 'fully equal in exactitude to that of the 
 elementary analysis ; so that the analysis made by me will not only 
 have a relative value, but fix the absolute value of the coals analyzed. 
 The detail of this method and the investigation leading thereto ap- 
 peared in the American Journal of Mining. [See Chapter III.] 
 
 As an average from which the various samples of Iowa coals but 
 slightly deviate, I may give the following percentage composition : 
 
 COMPOSITION. 
 
 VOLATILE — PEE CENT. 
 
 i 
 
 COKE- 
 
 — PER CENT. 
 
 
 Bitumen 
 
 , 
 
 .45 
 .05 
 
 .50 
 
 Carbon . 
 Ashes . . . 
 
 
 
 '15 
 
 Moisture 
 
 
 
 05 
 
 Total - 
 
 Total 
 
 50 
 
 
 
 
 
 Total combustion, 90 per 
 
 cent. 
 
 
 
 
REPORT OF STATE GEOLOGIST. ^ 211 
 
 In the Report of Prof. Whitney (vol. 1, pt. 1, page 399) it is stated 
 that the Iowa coals contain from 45 to 50 per cent of carbon. This 
 statement has been copied in Bailey and Hair's popular " Iowa Slate 
 Gazp.Ueer" Chicago, 1865, page 22. The actual per centage of car- 
 bon given by Whitney on the subsequent pages, as the result of his 
 own analyses, range all the way, and regularly, from 39 to 55 per 
 cent; that is, instead of varying only 5 per cent, the variation is 
 fully 161 ! 
 
 In commencing the more critical study of the Iowa coals, I very 
 soon discovered that notwithstanding this great variation in the coin- 
 position of the raw coal, the combustible itself varied but very little, 
 being composed of about 40 of bitumen and 54 of carbon. This 
 discovery was first mentioned by me in the " report of^progress " for 
 1866, and is in detail published in the American Journal of Mining, 
 for November 30, 1867. [See Chapter III.] 
 
 • The direct consequence of this discovery is that the heating effect 
 of our various Iowa coals is measured by their per centage of com- 
 husiible matter; for if this latter is of the same composition in our 
 Iowa coals, it follows that the heating effect is proportional to the 
 amount of this combustible. The per centage of combustible in Iowa 
 coals I have therefore called the value of these coals. 
 
 Furthermore, two coals will have the same heating eflfect, if they 
 contain the same weight of this combustible ; hence I call such weights 
 of the various Iowa coals as contain the same amount (100) of com- 
 bustible matter, the caloric equivalents of these coals. 
 
 If we had a certain weight of the pure combustible contained in 
 Iowa coals, but free from both ashes and moisture ; if this weight 
 could be had for one dollar, then the raw Iowa coal, containing on 
 the average 90 per cent of this combustible, would be worth 90 cents 
 for just that weight, and 111 pounds of the same coal would produce 
 the same amount of heat, as would be obtained by burning 100 pounds 
 of the pure combustible. 
 
 Since this is an entirely new method of valuation of coals, it will 
 be necessary to give an example in order to be fully understood by 
 the reader: 
 
 For instance, the coal from Henry Shock & Co.'s mine on section 
 
212 
 
 BEPORT OF STATE 6E0L.0G1ST. 
 
 eigM, township seventy -two, range fourteen, near Chillicothe, 
 Wapello County, gave by my analysis : 
 
 
 No. 346. Top. 
 
 No. 371. Bottom. 
 
 Rnf fific sravitv 
 
 1.361 
 
 84.82 lbs 
 
 1.308 
 
 Wpifjht of 1 cubic foot. . . 
 
 81.50 lbs. 
 
 Volylile matter 
 
 46.36 per cent. 
 53.64 per cent. 
 38.55 per cent. 
 46.47 per cent. 
 
 47.79 per cent. 
 
 Colse 
 
 Bitumen 
 
 Carbon 
 
 53.21 per cent. 
 41.67 per cent. 
 48.34 per cent. 
 
 Combustible 
 
 Ashes (red) 
 
 Moisture.: 
 
 85 02 per cent. 
 7.17 per cent. 
 7 81 per cent. 
 
 90,01 per cent. 
 
 (white) 3 87 per cent. 
 
 6.12 per cent. 
 
 1 100.00 per cent;. I 100.00 per cent. 
 
 REFERRED TO THE COMBUSTIBLE — 100 PER CENT. 
 
 Bitumen 
 
 45.36 
 
 54.64 
 
 8.44 
 
 9.19 
 
 46.32 
 53.68 
 
 Ashes 
 
 4 30 
 6 80 
 
 
 
 Equivalent I 117.63 | 111.00 
 
 It may be seen from this analysis that the combustible of the top 
 and bottom part of this coal -bank is ve.ry nearly the same; con- 
 taining about forty -six parts of bitumen in each one hundred of 
 combustible. The top coal contains eighty -five per cent of com- 
 bustible, the bottom coal ninety per cent of the same ; hence, if a 
 certain weight of the top coal is worth eighty - five cents, the same 
 weight of the bottom coal will be worth ninety cents, for heating 
 purposes ; the same weight of the pure combiTstible would be worth 
 one dollar. This is what is meant by saying the per centage of the 
 combustible expresses the value of our Iowa coals. 
 
 Again, in order to get one hundred pounds of pure combustible, 
 it is necessary to take nearly one hundred and eighteen pounds of 
 the top coal, or one hundred and eleven pounds of the bottom coal. 
 In other words, one hundred and eleven pounds from the bottom of 
 this mine contains as much of the heating material, or are capable 
 of yielding as much heat, as one hundred and eighteen pounds from 
 the top part of the mine ; that is, one hundred and eighteen of the 
 top coal are equivalent in regard to their heating or caloric effect to 
 one hundred and eleven pounds of the bottom coal. This is what is 
 meant by the caloric equivalent given in my analyses of Iowa coals. 
 
REPORT OP STATE GEOLOGIST. 213 
 
 Both of these two values, on which the practical importance of 
 the analyses of Iowa coal depends, are the result of my own inves- 
 tigations. They were therefore not given in any analyses of Iowa 
 combustibles previous to my own. 
 
 Finally, it will be observed, that the color of the ashes of the top 
 coal is red ; that of the bottom coal is white. The red color in the 
 ash being due to iron oxide in the same, resulting from pyrites (iron 
 combined with sulphur) in the coal, it is evident that the top coal 
 contains a considerable amount of sulphur, the bottom coal hardly 
 any. Hence the bottom Coal is good for blacksmithing purposes, 
 the top coal not ; if used for mere heating purposes, the top coal 
 will be more destructive to grate and boiler than the bottom coal. 
 
 The guide of the analyses in regard to the amount of coke or gas 
 that the coals may yield was given in the older analyses also ; but 
 since my analyses are made according to a- method giving strictly 
 rehable results, the estimates here given for gas and coke may prove 
 a more safe guide for those who either would manufacture coke, in 
 order to enable them to ship coal to greater distances, or who would 
 select a coal for a gas worksi 
 
 I have dwelled thus lengthily upon this sample in order that the 
 people may be enabled to understand the meaning of the figures 
 given as the result of my analyses of Iowa coal, particularly since 
 these two expressions of value and equivalence never before have 
 been connected with proximate analyses of coal. This valuable 
 practical result I claim as one discovered during the progress of the 
 Geological Survey of Iowa. 
 
 In order to compare our Iowa coal with those of other parts of the 
 world, so as to test the popular opinion that our Iowa coals are of 
 an inferior quality, I have analyzed the following seven samples of 
 fuel, contained in my private cabinet of minerals. For the sake of 
 completeness, I have also added my analysis of the most volatile solid 
 fuel, asphaltum. It must be observed, that these analyses are com- 
 parable, having all been execut*ed according to my improved method. 
 
211 
 
 KEPORT OF STATE GEOLOGIST. 
 COMBUSTIBLE — 100. 
 
 NAME AND LOCALITY. 
 
 
 
 
 
 4J 
 
 
 
 
 
 fl 
 
 
 d 
 
 
 
 V 
 
 
 
 a 
 
 
 a 
 
 (U 
 
 
 03 
 
 o 
 
 .0 
 
 e 
 
 
 ■3 
 
 S 
 
 
 m 
 
 
 C 
 
 
 
 CQ 
 
 <j 
 
 S 
 
 Ed 
 
 Alsphaltum 
 
 Peat, from Ireland 
 
 Bituminous wood, from Salzliausen, Hessia. 
 
 Brown coal, from Arbesan, Bohemia 
 
 Brown coal, from Bilin, Bohemia 
 
 Bituminous coal, from Beuthen, Silisia 
 
 lowA COALS, average 
 
 Cannel coal, from Wigan, England 
 
 Anthracite, from Pennsylvania 
 
 26 
 
 74 
 
 4 
 
 ? 
 
 104 
 
 36 
 
 64 
 
 3 
 
 16 
 
 118 
 
 31 
 
 69 
 
 5 
 
 10 
 
 115 
 
 36 
 
 64 
 
 3 
 
 11 
 
 114 
 
 40 
 
 67 
 
 16 
 
 00 
 
 /133 
 
 51 
 
 49 
 
 21 
 
 5 
 
 136 
 
 50 
 
 50 
 
 5 
 
 5 
 
 110 
 
 61 
 
 39 
 
 10 
 
 3 
 
 112 
 
 94 
 
 6 
 
 2 
 
 2 
 
 104 
 
 96 
 
 85 
 87 
 88 
 81 
 80 
 90 
 89 
 96 
 
 [For the sake of perspicuity the decimals have not been given.] 
 
 The excess of the equivalent above 100 expresses the amount of 
 impurities [ashes and moisture] in the coal. For the same kind of 
 fuel its heating effect will therefore be the greater for equal weights, 
 the less this equivalent exceeds one hundred. Now in this regard 
 our Iowa coals are as good as any, for the average shows only ten 
 parts of impurities for 100 parts of combustible. Though in 
 particular cases this amount is frequently exceeded, it is also very 
 often much less. Thus tlie coal from the top of the bank at Business 
 Corner, Van Buren county, has an equivalent of only 102.73 : that is, 
 for each 100 of combustible this coal contains only 2f of foreign 
 matter, or less than the Anthracite analyzed. The equivalent of the 
 coal from the bottom of Richardson's mine, two miles west of Fairfield, 
 Jefferson county, is a little lower yet, only 102.37, and indeed the 
 lowest of any Iowa coals yet analyzed ; that is, it is the purest of all 
 samples investigated, containing not even 2J parts of non - combusti- 
 ble matter for each 100 of combustible, or less than one pound in 
 forty pounds of pure combustible matter. 
 
 Nor is the kmd of ashes in our Iowa coals of a more obnoxious 
 quality than that of other coals. The ashes from the bottom coal of 
 Henry Shock & Go's mine, Wapello county, or from the bottom coal 
 of the Iowa Coal Company's mine at Oskaloosa Station, Mahaska 
 county, and from many other samples'of Iowa coa.1, is as pure white 
 as the ashes from the English cannel coal, analysis of which is above 
 given. Nor is the ash of any Iowa coal more ferruginous, or the 
 corresponding coal, more sulphurous than corresponding coal Irom 
 
REPORT OF STATE GEOLOGIST. 
 
 215 
 
 other regions; the simple fact of the matter is, that everywhere we 
 have both poorer and better qualities of coal in these respects, and 
 while none of our Iowa coals is worse than poor coal's from other 
 countries, there are no bituminous coals better in any country than 
 the best coals of our State, both in regard to the amount and quality 
 of the impurities of the fuel. 
 
 Again, it will be observed that the amount of carbon in the various 
 combustibles analyzed ranges from 40 to 94. The average would be : 
 Peat and brown coal, 40 per cent carbon. 
 Bituminous coal, 50 per cent carbon. 
 Anthracite, above 90 per cent carbon. 
 
 It therefore appears that our Iowa coals are as rich in carbon as 
 the average of bituminous coals tho world over. We have among 
 the numerous samples analyzed found one sample almost identical 
 with the genuine cannel coal from Wigand, England, mentioned 
 above ; this coal is from the top of the Alpine Coal Company's mine, 
 at Alpine, on the Des Moines river, in the southeastern township of 
 Wapello county. This will become plain by comparing the results of 
 my analysis : 
 
 
 CANNBL COAL. 
 
 
 Prom Al- 
 pine, (top, 
 No. 336.) 
 
 From 
 Wigand, 
 England. 
 
 Bitumen 
 
 40.37 
 
 59.53 
 
 • 100.00 
 
 8.09 
 
 4.73 
 
 113.81 
 
 88.65 
 
 39.05 
 
 Carbon ... . 
 
 60.95 
 
 Combustible . . 
 
 100 00 
 
 
 [wliite] 9.53 
 3.89 
 
 Jnoisture 
 
 
 113.93 
 
 Value 
 
 88 56 
 
 The correspondence in the composition of these two samples, the 
 one from England, the other from the Des Moines Valley, is, to say 
 the least, most remarkable ; at any rate this Iowa coal is as good as 
 the English cannel coal here analyzed. 
 
 The column headed " Value " in the preceding table has not the 
 same signification as it has for our Iowa coals, for the per centage of 
 bitumen in the combustible of these fuels varies very much, so that 
 
21g REPORT OF STATE GEOLOGIST. 
 
 an equal per centage of combustible for the various kind of fuel does 
 not imply an equal heating effect. Indeed we know, that while one 
 pound of carbon, by cnmplete combustion, will produce heat sufficient 
 to heat eighty - one pounds nf water from the freezing to the boiling 
 point, or to convert about twelve pounds of water into steam, the 
 various gases constituting the volatilized bitumen have a different 
 heating power — some pi^oducing less, others producing more heat 
 than an equal weight of pure carbon. 
 
 According to the determination of the late Prof. Forchhammer, of 
 Copenhagen, as stated in his lectures, one pound of the various fuels 
 will by combustion raise the temperature of the following number of 
 pounds of water from the freezing to the boiling point: 
 
 Wood, air- dry 22 lbs 
 
 Peat 25 lbs 
 
 Brown coal .. 29 to 36 fts 
 
 Pit coal (Bitumii ous dial) 50 to 60 Iba 
 
 Anthracite 70 8)3 
 
 While these figures state the amount of heat that can be obtained, 
 but which actual practice falls very much short of, we have some 
 experiments of the Prussian Chemist Brix determining the number of 
 pounds of water actually converted into steam by means of one 
 pound of fuel in the same heating apparatus ; his results were : 
 
 Wood 4 to 5 lbs 
 
 Peat 5 to 6 lbs 
 
 Brown coal 5 to 6 lbs 
 
 Bituminous coal 6 to 7 lbs 
 
 Charcoal, dry ; 7J lbs 
 
 Since one pound of pure carbon, if co^npletely utilized, would 
 convert twelve pounds of water into steam, this last figure shows 
 how much even carefully conducted experiments fall behind this 
 theoretical standard. 
 
 By means of these figures we see, that for, equal v, eights the heat- 
 ing effect is smallest for wood, greater for peat, still greater for 
 brown coal, and that bituminous coal, or rather pit coal (steinkohle 
 of the Germans) is only surpassed by anthracite in its heating 
 effect. 
 
REPORT OF STATE GEOLOGIST. 217 
 
 Since now my extensive analyses have proved that our Iowa 
 coals are fully equal to the average of bituminous coal, we must con- 
 sider the popular opinion that Iowa coals are not as good as others, 
 a mistake caused by comparing our bituminous coal to a fuel like 
 anthracite. The fact is, that the composition and hence the value 
 of the coals of this State, as far as investigated, is fully equal 
 to that of the true stone coal all the world over ; and if the work- 
 able banks in our State are not as thick as those of some other 
 countries, we have them close at hand and can run the railroad - track 
 right into the mine, while in those otherwise more favored regions 
 they have to dig two thousand feet deep in order to reach the coal. 
 
 in. GENERAL RESULTS ON THE SOUTHEASTERN PART OE THE IOWA 
 
 COAL - EIELD. 
 
 In the course of my reductions of the analyses of Whitney and 
 Blaney, I frequently found a considerable difference between the 
 composition of the upper and lower part of the same coal bank. At 
 the same time I discovered a remarkable uniformity in regard to the 
 composition of coal from various parts of the field, and reported the 
 same in a paper inserted in the American Journal of Mining for 
 November 30. [See Chapter IIF). My new method of reduction in 
 revealing such differences in the analyses of others, appeared to me 
 to be a proper instrument to apply to my own systematic analyses in 
 order to discover the general law in regard to the deposit of carbon- 
 aceous matter in the vertical, if any exists. 
 
 The State Greologist having selected specimens for analyses both 
 from the upper and lower parts of each coal - bank the material 
 thus placed in my hands is very considerable and most valuable as a 
 systematic collection representing the mineral fuel of Iowa. Each 
 specimen bears a green circular label with a number by means of 
 which its full history can be obtained from the catalogue ; when 
 analyzed, a rhombic, red label is added, with the same number, thus 
 at the same time increasing the security against any possible loss of 
 the history of the specimen. It is only in this way that a collection 
 of coal is worth all it costs to accumulate the same. In regard to 
 28 
 
218 
 
 REPORT OF STATE GEOLOGIST. 
 
 the present collection of Iowa coals, beside securing the permanent 
 value of the specimens as such, they are also the means which may 
 be used at any time to test the correctness of my analyses. 
 
 The portion of the coal - field from which coal has been analyzed 
 forms a strip of land about twenty miles broad in the direction of 
 the Des Moines river from Farmington to Knoxville; this being a 
 distance of more than eighty miles, the part chemically investigated 
 covers about 1,600 square miles of our Iowa coal-field. Of course 
 many more analyses will have to be made even for this portion of 
 the field ; beside this investigation will have to be extended to the 
 wliole of the coal - field. 
 
 The most important result of my investigations consists in the 
 discovery of two chemically distinct banks of coal, traced the one 
 for seventy, the other for fifty miles along the Des Moines river. 
 This is, as far as I know, the first time that the chemical analysis of 
 specimens in the laboratory has been the means of tracing a coal- 
 bank across the field. 
 
 Bank First. — The existence of this bank I ba^e upon the identity 
 of the coal in mines, both at the bottom and at the top of the same. 
 In the following I give the final result of my analyses of these speci- 
 mens, referred to the combustible taken as 100. The "numbers" 
 are those put on the labels of the specimens in the collection ; th<i 
 first always referring to the sample from the upper ; the second to 
 that from the lower part of the coal bank : 
 
 
 MINE. 
 
 DISTANCE 
 
 COUNTY. 
 
 BITUMEN. 
 
 
 TOP. 1 EOT. 
 
 330,339 1 Carmine's bank 
 
 20 miles 
 
 50 miles 
 
 Van Buren 
 
 46.4 
 
 46 9 
 
 47.3 
 
 5«fi 
 
 385,396 
 
 Young & Stttbbs' bank. . . 
 Nossanian'sbaDk 
 
 
 52.4 
 
 405,3i3 
 
 
 
 51.8 
 
 » 
 
 lean 
 
 
 
 
 46.9 
 
 53.3 
 
 Here, and in all subsequent tables, I give only one decimal to the 
 number of per cent ; that is fully as much as can be relied upon, for 
 this decimal expresses the composition within the fractional of one 
 thousandth. 
 
REPORT OF STATE GEOLOGIST. 
 
 219 
 
 It will be seen that Young & Stubbs' bank, both at the top and at 
 the bottom, coincides with this mean ; at Carmine's bank the two 
 figures are a little farther apart; at Nossaman's they are a little 
 nearer together. The mean difference between the bottom and top 
 coal is 5.4 per cent of bitumen more at the bottom than at the top. 
 
 In regard to the amount and quality of the ashes I find (always 
 for one hundred combustible) : 
 
 AMOUNT, 
 MINE. 
 
 Carmine's 
 
 Young & Stubbs' 
 
 Nossaman's 
 
 Mean 
 
 EOT. 
 
 8.0 9.5 
 4.3 12.5 
 6.9 23.5 
 
 6.4I 14.5 
 
 COLOK OF ASHES. 
 
 TOP. 
 
 Blackish brown. 
 
 Brown 
 
 Reddish pink. .. 
 
 1 Reddish. 
 
 Light grey 
 
 Whitish pink 
 
 White and pink. 
 
 Whitish 
 
 From this table it will be seen that the top coal always contains 
 less ashes than the bottom coal, while at the same time the ash of 
 the bottom coal is more white, and that of the top coal more reddish. 
 
 When it is considered how many circumstances have to conspire in 
 order to produce so close a harmony in so many particular quantities 
 relating to these three mines, it will be understood how I am led to 
 consider this agreement a proof of the sameness of the coal bank. 
 
 Bank Second. — The corresponding tables for this bank are : 
 
 
 MINE. 
 
 DISTANCE. 
 
 COUNTY. 
 
 BITUMEN. 
 
 
 TOP |BOT. 
 
 370,360 1 i^rnwn Xr. fJnrlfrfiv'H . 
 
 20 miles 
 
 25 miles 
 
 
 
 WaDeilo 
 
 51.3 
 
 50.4 
 49.4 
 
 50.4 
 
 46 4 
 
 390,384 
 348,350 
 
 
 
 45 9, 
 
 Roberts and Fisher's. . . . 
 
 Marion 
 
 47 
 
 Me 
 
 an 
 
 
 46.2 
 
 The law of variation in this bank is the reverse of what it is for 
 bank first ; for while in bank first, the bottom coal contains 5.4 more 
 of bitumen per hundred combustible, than the top coal, here in bank 
 second, the top coal contains 3.6 more than the bottom coal. It will 
 further be observed that the top coal of bank first (46.9) is almost 
 identical with the bottom coal of bank second (46.2). 
 
220 EEPORT OF STATE GEOLOGIST. 
 
 For the ashes, we have in bank second : 
 
 TOP. BOTTOM. 
 
 TOP. 
 
 BOTTOM. 
 
 Brown & Godfrey's. . . 
 Iowa Coal Company's. 
 Roberts & Fisher's. . . . 
 
 9.4 
 3.9 
 7.1 
 
 Mean ! . . . i 6.5 
 
 13.0 
 7.4 
 9.5 
 
 9.7 
 
 Red 
 
 Br'wnish 
 Red 
 
 Reddish. 
 
 Pale pink 
 
 White 
 
 Brownish 
 
 More whitish 
 
 In regard to the ashes, bank second follows the same law as bank 
 first ; the lower layers contain the most ashes, but the least of iron 
 (red color) in the same. 
 
 From this circumstance, I conclude that bank second belongs 
 above bank first ; the correctness of this conclusion is further con- 
 firmed by the fact that the upper part of bank first and the lower 
 part of bank second not only agree in the main per centage of bitu- 
 men (which is respectively 46.9 and 46.5), but that they actually 
 vary in the same manner, increasing in bitumen toward the north- 
 west ; the first bank, top, from 46.5 to 47.2, and bank second, bot- 
 tom, from 46.4 to 47.4. 
 
 The mean of ashes in bank first is 10.1 ; in bank second 8.8, and 
 as in each bank the amount of ashes increases downward, this is a 
 further proof that bank second is above bank first. 
 
 According to these chemical investigations of the lower Des 
 Moines coal - field, the following may, in the absence of my drawings, 
 be given as a representation of this field : 
 
 FOR 100 .COMBUSTIBLE. 
 
 Bank 3, 
 or upper, 
 
 Bank 1, or 
 lower, 
 
 .50 7., 
 
 (increase upward) 
 
 .46 8. 
 
 - OOLOK OF ASHES. 
 
 . . red 
 
 PAKT. 
 top. 
 
 bottom. 
 
 t op . . . . 
 
 (increase downward) 
 bottom 53 10 white 
 
 intermediate 
 colors 
 
 As far as I have examined the specimens, the Van Buren county 
 and the Jefferson county mines belong all to the first or lower bank. 
 All of the samples analyzed from mines in the counties of Wapello, 
 Mahaska and Marion, belong to the second or upper bank, excepting 
 Nossaman's bank in Marion county. 
 
REPORT OF STATE GEOLOGIST. 221 
 
 The amount of coal easily accssible along the border of the coal- 
 field is immense ; but the great future of this commonwealth depends 
 still more upon the continuation of these riches under the overlying 
 rocks toward the deeper portions of the coal -basin. In the accu- 
 rate and comprehensive study of the coal I believe we have now a 
 very effective auxiliary for the exploration of this basin ; and it may 
 therefore be expected that this auxiliary will be made available. 
 
222 
 
 REPORT OP STATE GEOLOGIST. 
 
 
 Q 
 
 < 
 
 
 H 
 
 
 
 m 
 
 OQ 
 tH 
 I-l 
 
 
 h! 
 
 OQ 
 
 E-i 
 
 P 
 o 
 o 
 
 w 
 p 
 
 OrH 
 H I 
 
 mS 
 
 o 5 
 
 BS 
 
 o 
 
 to I 
 
 OS 
 
 0-!| 
 OS 
 
 ' .-ag 
 3.5fgf=SfiB 
 
 inatBAinba 
 
 Oi QC t^ 1~ ^ O I^ 
 
 ■ajnjSTOH 
 
 •sonsy 
 
 •uoqi'BO 
 
 LO Ti lO CO 00 o ic 
 dcci^^oc'ioco 
 
 •naumiia 
 
 •noqjBO 
 
 •naumiig; 
 
 •saqsv 
 
 •ajtusioM 
 
 •83[O0 
 
 •8II}13IOA 
 
 sinon ni 
 
 
 sqi nru -qno 
 I JO TOSia^to. 
 
 •ABjS 'oaag 
 
 Mm 
 MS 
 
 CDlC lO 
 i-HO »-l 
 
 J c: O O Ci 
 
 COCO j 
 
 ^ca I 
 
 ~ rH i-H L/j -^ ;■■: 
 
 
 coca [ CO 
 00 CO I ~ 
 
 H_ CO CO ^ CO -^ 
 3 r-i r-i CD CO u5 
 
 CIIOCO^OCO 
 O t»- l-~ CC l> ^ i-o 
 
 P -H Tfi M< -Tl LQ 
 
 CJ ->[ C I — i r-J -t^ O 
 
 — 'O i-C lO 'C LO -71 
 
 coco j c 
 OCO I c 
 
 -1 C-] -t ^ -TH -F -rc^ 
 
 CO O "* O tM m ;q 
 
 0.-lTtH 
 
 ess 
 
 ssan^ioiqx 
 
 
 HW&hMBWH fq I I 
 
 O 
 O 
 Hi 
 
 
 •laqBi.iio jaqtan^ 
 
 MS - 
 
 *i w o 
 
 as ■^ 
 
 
 m a 
 
 tj pq 
 
 <p 
 
 n .3 
 
 O 9 m n H 
 
 !> a CO J T3 
 
 ^."0<! q 
 
 i?5 W M 
 
 QC C^ ''^ —I CO O <=> OS<» 
 (MCOCOCOCO>T<CO (MM 
 
 CO CO CO <:^ CO CO CO coi-i 
 
 p 
 o 
 o 
 
 o 
 
 IE 
 t-5 
 
 J3 
 
 COCvlOS oci-*oo I -v 
 
 aj F^ v ^ 
 
 *mt>p; 
 
 t>OCOCl I lO 
 
 oooc<i-t 
 
 e;^^:o I .-( 
 i-i^.-it-I j CO 
 
 IS 
 
 oocqi> i>(Mcqi> I 
 
REPORT OF STATE GEOLOGIST. 
 
 223 
 
 WrHQO 
 
 (M^ 00 O I- 
 
 ioSSi/ 
 
 ciopaicQ m 
 
 com .-htH 
 
 '^ "^ ''v '^ I ^ 
 
 a2 1> l^ 
 
 
 CO(NrH 
 
 ococcun I ■■ 
 
 lO '^ Tj^ lo I 1 
 
 "-PO'i-Jm 11 
 T^IIQIQ-Ji I - 
 
 
 PCDOO (MMOOCl 
 
 CO lO 03 I— OS t^ CO 
 H!N COCOt-HCD 
 
 SCO OOQOCOQO 
 
 o;s;°!g;s;| 
 
 BWH PseiacQ . 
 
 CO ^ 
 
 a! & 
 r9 » 
 
 S' .s 
 a a 
 
 •I 
 
 o 
 
 S 
 
 >iHC£) THOt>0 
 il>co coj^ineo 
 JCOCO cocococo 
 
 1=) 
 o 
 o 
 
 M 
 
 w 
 <), 
 
 
 CllOCOOD^CO , 
 r-J CO ui lO "^ 1-^ I 
 
 l-^ CO CI ■* l> o 
 
 CO i-T C3 '!i' CO CO I -^ 
 
 ■O -^ ■*T< >Q fJ to I iO 
 
 lo CD ■# cq c^ CI 
 
 OHOiCCi'-J'^ j c 
 
 ci-pa5ci<^'-j I c 
 —' -f -71 CO ~n ^ i - 
 
 C"! co' c<i to "^ ^ I t- 
 
 co t^ Tji ^ c: lO 
 
 lO -f^ c4 «* 2 !;r 
 
 «:ccmcc ^ -g> ' 
 
 Ci C-l Oi lo'^. "f^ I <: 
 
 lO :ocD oo^ 
 
 lOlO-rfOO-^ I CO 
 
 , ! Ji-H"to<a3t:^ ^' 
 
 -^ ■TJ1 LO -^ ^IJ^t^l^H 
 
 Tt< Tj< cq CO lo CO 
 
 cdoOCOrliCO 
 QOOICOOOOOOO 
 
 fiCNCOCOCO CO 
 
 
 HPQHM^iM I 
 
 iraioo"*ooQO 
 
 1>05 0SQOCOOS 
 CO CO CO CO CO CO 
 
 o 
 o 
 
 !?; 
 
 o 
 
 t-H 
 
 TJ 'O 'd Ti 71 
 
 CD a o) Q 5 
 r^'iz! oj CD:::! 
 
 ; CO ZS CI (M 
 CO O^ >-i ci —I «i 
 CI CI OJ --( C>) 
 
 ci CO t-^ U3 1> 1-^ -r 
 
 00 CO -^ l-~ 'fi C-1 
 
 ciooc^t^ca 
 
 00 pH erf CO CO 'ijl 
 — to lO lO lO lO 
 
 00 1> XH '!f1 CO CO I 
 
 - Ol r-1 CO CO ^ I 
 
 D CI CC CI ^ ] o 
 
 ^vK j 
 
 CO CO ClO ■^ .— I ■— ( 
 
 ■n^ CO OJ CO CO lO I 
 COCOC^Tf co-^ 
 
 lococ^cqcoco 
 
 HWiiHpq I 
 
 
 ■3 s 
 
 t1 Q 
 
 ■3 g 
 P3 p 
 
 COOiOOOiOCO 
 
 -^■-j^iooth 
 
 )COCO"^CO 
 
 
 
 
 ni 
 
 
 
 
 
 
 
 
 P 
 
 
 t; 
 
 
 a 
 
 
 PC 
 
 
 p 
 
 
 
 
 
 
 
 
 
 
 or 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 c 
 
 
 Tji 
 
 
 c 
 
 
 lO 
 
 
 
 
 
 
 en 
 
 
 U3 
 
 
 (M 
 
 
 cq 
 
 
 
 
 
 
 c 
 
 
 GO 
 
 
 f? 
 
 
 ? 
 
 
 
 
 
 
 e 
 
 
 
 
 
 
 o 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 u- 
 
 
 
 
 
 
 Cft 
 
 
 
 
 
 
 
 
 
 
 ■t; 
 
 
 CO 
 
 
 C; 
 
 
 5 
 
 
 c 
 
 
 1> 
 
 
 J? 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 'N 
 
 
 cq 
 
 H 
 
 C 
 
 
 
 {^q 
 
 
 
 
 p 
 
 QC 
 
 >* 
 
 o 
 
 o 
 
 n 
 
 
 
 o 
 
 C^ 
 
 
 
 
 - P 
 
 - O 
 
 
 M 
 
 n- 
 
 o 
 
 r-^ 
 
 W 
 
 C^ 
 
 M 
 
 r^ 
 
 tc 
 
 
 o 
 
 ^ 
 
 
 : i-P 
 
 — 
 
 O 
 
 oc 
 oc 
 
 O 
 Ph 
 
 
 Ph 
 
 
 
 
 
 
 
 
 
 
 
 t— ( 
 
 
 i> 
 
 
 
 ^ 
 
 
 4 
 
 
 
 
 
 
 
 
 
 
 a 
 
 
 
 
 
 
 
 
 
 
 t>^ 
 
 
 H 
 
 
 
 
 
 
 b 
 
 
 fl 
 
 
 S 
 
 
 
 
 r) 
 
 
 t 
 
 
 o 
 
 
 fcs 
 
 
 s 
 
 
 
 
 i/i 
 
 
 
 
 Cl) 
 
 
 ^ 
 
 
 R 
 
 
 •^ 
 
 
 ^ 
 
 
 
 
 01 
 
 
 1 
 
 
 S 
 
 
 
 l§ 
 
 
 rr 
 
 
 r?i" 
 
 
 a 
 
 
 * 
 
 T S 
 
 a d 
 
224 
 
 EBPORT OF STATE GEOLOGIST. 
 
 s 
 
 § 
 
 
 
 O 
 
 ^ o I 
 
 <d ^ I 
 
 ^ H I 
 
 2 I 
 
 OH 
 
 W - 
 
 H 
 
 oS 
 " i 
 
 MO 
 
 
 •^(Xi3ATnTE)a 
 
 •ajn-jejoM 
 
 lOCqi>l003 lO 
 
 •satisv 
 
 •uoqji30 
 
 •atiTBA 
 
 ■uoqjBO 
 
 ■naramia 
 
 ■g8t[SV 
 
 CDl^QOCiC-l OO 
 
 ■^lOioiftira 
 
 CO^QOOOO 
 
 '9jn:jST0H 
 
 'J'Cqt-^dHt- lO 
 
 •33100 
 
 •aniBiOA 
 
 JO )q8i3AV 
 
 M 
 
 H 
 
 p 
 
 O 
 O 
 
 ^ rt ^ OS ■ 
 
 »HCqM-*tC 
 
REPORT OF STATE GEOLOGIST. 225 
 
 All terms used in the preceding tables having been explained in 
 the second article on the fuel of the State, only a few remarks on 
 the figures themselves need be added. 
 
 The means here given for each county are of course liable to 
 change by the investigation of more mines in each county, but the 
 fact that the samples analyzed were not selected, but rather taken at 
 random, together with the fact that the final results indicate a gradual 
 change in the mean of the coals from the consecutive counties, rather 
 proves that the results thus far obtained will not be materially altered 
 by increasing the number of specimens analyzed for each county. 
 
 From the last table it will be seen that the Iowa coals are most 
 bituminous in Van Buren county, and that the amount of bitumen 
 decreases slowly in a direction up the Des Moines river. The same 
 is true in regard to the per centage of volatile matter. On the 
 whole, the coals from lower down the river therefore are more baking 
 and also better for gas - making. At the same time they contain the 
 smallest per centage of both ashes and moisture, that is, the coals 
 improve in purity down the river. 
 
 As an ofi'set to this advantage of the coals from the lower counties, 
 the coals from the counties higher up Des Moines river contain both 
 a greater per centage of coke in the coal and a greater proportion 
 of carbon in the- combustible. For coking, and therefore also for 
 smelting purposes, these latter are thus better than those from the 
 lower counties. 
 
 To express this difference in the plainest language, I might say : 
 The coals from the lower counties on the Des Moines river are, on 
 the whole, more bituminous, more baking, burning with more flame, 
 leaving less ashes, than those from the counties higher up the river; 
 but then the latter give more coke, and a more intense heat than the 
 former. 
 
 In following any one of the columns downward, it will be noticed 
 that this change is very gradual and of but small amount ; on the 
 average, only four per cent difference. It will also be seen that the 
 actually determined mean for the State is very nearly as stated in 
 round numbers in the second article ; the only deviation being two 
 per cent greater amount of moisture, and two per cent smaller 
 
 amount of bitumen. 
 29 
 
226 KEPORT OF STATE GEOLOGIST. 
 
 It must be borne in mind that the values here referred to are 
 means for counties, and the fact that the coals from Marion county 
 contain ten per cent of ashes must not be understood as meaning 
 that all coals from that county actually contain so much ; the mean 
 of ten per cent results from some containing more, others less, than 
 this amount. 
 
 Again, though on the whole the per centage of ashes increases in 
 an upward direction along the Des Moines river, it must not be 
 understood that there are no coals in the lower counties with more 
 ashes, no coals in the upper with less ashes. By reference to the 
 preceding table we see that the lower part of Carmine's bank con- 
 tains 8y\ per cent of ashes, (VanBuren county), while the sample 
 from Redhead's mine in the city of Des Moines only contains 2j\ per 
 cent of ashes. 
 
 All the results of the analyses here reported have been represented 
 on a map, drawn on a scale of four miles to the inch. By a peculiar 
 method, all particulars of any coal - bank are represented to the eye. 
 The publication of such a map must of course be delayed until much 
 more material has become available. 
 
 In conclusion I would add one more observation. This fourth 
 article, giving the results of my analyses, is a statement of facts ; 
 any one who doubts it has all means of satisfying himself by having 
 repeated the analysis of the identical specimen now in the cabinet 
 of the State University. The statement in regard to the existence 
 and relative position of the two coal - banks, as contained in the third 
 article, is, to a considerable extent, a conclusion. With the increase 
 of the number of specimens analyzed, the basis of that conclusion 
 may change, and with it the conclusion itself may be modified. 
 Again, there is a possibility that two banks might be difi"erent, 
 and yet be identical in their chemical composition; at any rate, the 
 impossibility of such a condition of things has not been proved ; but 
 making due allowance for all these circumstances, I repeat that the 
 tracing of the two coal - banks along the Des Moines river is the only 
 one yet made that I know of; and although both the novelty of this 
 attempt and the facilities for such purpose, limited number of analy- 
 ses, calls for further chemical and geological research. 
 
REPORT OF STATE GEOLOGIST. 227 
 
 V. THE CHEMICAL HISTOKT OP COAL. 
 
 The great economical importance of coal, the peculiarities of the 
 distribution of this fuel and the many remarkable physical and 
 chemical characters make the question as to its origin not only one 
 of great interest, but also of great diflSculty. 
 
 Although many writers on geology consider the complete history 
 elucidated, and with great assurance give detailed accounts of the 
 precise mode of the formation of coal, many eminent authors do not 
 hesitate to acknowledge, that hardly any thing but the mere vegetable 
 origin of coal is demonstrated. Mr. Hunt, states the case with 
 perfect frankness in the recent supplement to lire's Dictionary, when 
 he says : " That coal is derived from the vegetable kingdom, no 
 longer admits of doubt ; but the class of plants to which more 
 especially we are to look for the origin of coal, is still a matter of 
 much uncertainty, and the conditions under which the change is 
 brought about is very imperfectly understood, and indeed, by many 
 geologists entirely misconceived." 
 
 The greater part of this uncertainty seems to be due to the 
 apparent neglect of the chemical properties of the coal. Professor 
 F. Mohr of Bonn, Germany, has lately shown, that all known facts 
 in relation to coal are best explained by considering the stone - coal 
 as a result of the carbonization of marine plants, algae, and that 
 this even will explain a great number of well ascertained geological 
 phenomena, which protest against the generally accepted hypothesis 
 that coal is due to land - plants. My own investigations of the Iowa 
 coal have contributed very much to the conviction I now hold, that 
 the theory of Mohr in regard to the formation of stone - coal is the 
 true one ; at any rate, the theory of Mohr does not solely rest upon 
 the nature of accidental matters in the coal, but upon a careful 
 investigation of the body of the coal itself. 
 
 Referring to the first article, it may be remembered that wood, 
 peat and brown coal were there ascribed to land - plants, coal, to 
 sea - plants. In order to prevent a possible misunderstanding, I shall 
 instead of coal, use the word stone - coal, to indicate all true coals 
 from anthracite to our bituminous coal of Iowa. 
 
 Forests and peat r.bogs grow before our eyes ; their origin is well 
 
228 REPOKT OF STATE GEOLOGIST. 
 
 known. Brown coal lias in its mass so plainly the structure of land- 
 plants, that its origin is not questioned; besides, we here in the 
 Mississippi valley know that we are in the very coal - era, for the 
 immense amount of trees brought down to the gulf of Mexico from 
 all parts of this great valley, is now forming a great brown coal 
 deposit, like those now explored on the Pacific coast of this country. 
 Leaving everything of a purely geological nature to others, I shall 
 confine myself to the consideration of the stone - coal as a substance 
 which could neither have been formed from trees, nor from peat 
 bogs, nor from brown coal, but only from sea- weeds. It will be the 
 simplest to consider the actual contrast between the properties of 
 wood, peat and brown coal, being the products of woody fibre on the 
 one hand, and the properties of stone - coal, which we stated to be 
 produced from sea - weeds, on the other hand. 
 
 First. — If wood is heated in a closed vessel, so that the air can 
 not get to the wood, this latter will never fuse, but only become 
 charred. All are familiar with the fact, that charcoal shows even 
 the nicest details of the structure of the wood from which it was 
 made. So, also, brown coal, and peat, never fuse, but retain their 
 structure. 
 
 But most true stone - coals do fuse under these circumstances ; all 
 Iowa coals that I, as yet, have analyzed, did fuse ; some very easily. 
 
 That this marked difi'erence depends on the structure of the 
 substance, we know from the fact, that sugar in charring does fuse, 
 while woody fibre does not ; both substances have precisely the same 
 elementary composition, but they diifer widely in regard to 
 structure. 
 
 This diiference between stone - coal and the other fuels is contrary 
 to both the peat -bog theory and the wood theory; but if stone- 
 coal is formed of sea -weeds, this property is a necessity, for all 
 sea - weeds when thus treated, fuse very readily. 
 
 Another difi'erence we have, is the fact that wood continues to 
 burn when taken from the flame — stone - coal not ; the coals from 
 sea -weeds act in this respect precisely like stone-coal. 
 
 Second. — When pulverized brown -coal or peat are boiled in 
 pottassa lye, a deep brown, almost black, solution is obtained; when 
 
REPORT OF STATE GEOLOGIST. 229 
 
 stone - coal is treated in the same way, the lye remains almost color- 
 less. This coloring matter is called humus ; it is also found in our 
 soils, and is a product resulting from woody fibre. Since stone - coal 
 is without humus, it proves itself devoid of woody fibre. 
 
 Third. — Stone - coal has always but a few per cent of moisture ; 
 brown coal and peat retain a very great amount of moisture with 
 pertinacity. Thus, in the Irish peat analyzed by me, I found sixteen 
 per cent of moisture. In brown coal from Bilin also sixteen ; in 
 stone - coal from Silesia, only five ; cannel coal from Wigan, only 
 three. All of these specimens had for several years been kept in 
 the same case in the air - heated labaratory, so that they represent 
 these fuels as thoroughly and equally air - dry. Now this is quite 
 general; all chemists are aware of this radical difi'erence between 
 stone - coal and those fuels which we know to be derived from woody 
 fibre. Hence, again the conclusion .,th^t stone -coal is not derived 
 from woody fibre. 
 
 Fourth. — When stone-coal is subjected to dry distillation in the 
 retorts of the gas - works for the purpose of manufacturing illumin- 
 ating gas-, great quantities of ammoniacal liquid is obtained ; in fact, 
 almost all the ammoniacal salts now used in the arts, are thus 
 extracted from stone - coal. 
 
 When wood is subjected to the same treatment, no such ammon- 
 iacal liquid is obtained ; on the contrary, instead of this alkaline 
 liquid, an acid is obtained, called wood - vinegar. Peat and brown 
 coal treated the same way, likewise give an acid liquid. 
 
 This great difi'erence forms the basis of Mohr's theory, here 
 advocated ; it is indeed utterly impossible to see how the nitrogen 
 necessary to form the ammonia should have got into the woody fibre, 
 if they were the source of stone - coal. On the other hand, sea- 
 weeds are exceedingly rich in nitrogen, and if they were charred 
 in any way, much nitrogen would remain. 
 
 That this difference between stone-coal and the other fuels is 
 constant and general has been proved by an extensive series of 
 experiments performed by the German chemist, Kremers. 
 
 Fifth: Near the sea -shore we always find the smell of sulphu- 
 retted hydrogen more or less perceptible ; we know it to be due to 
 
230 REPORT OF STATE GEOLOGIST. 
 
 the decay of sea - weeds thrown on the shore. Wood, when thus rot- 
 ting, does not emit such odor. ^ 
 
 The amount of sulphur in the coals is very great ; the smell near 
 the gas - works sufficiently known is an abundant proof. Brown coal 
 and peat do not contain so much sulphur; the iron associated with 
 these fuels is more commonly found as carbonate or oxide than as 
 sulphuret. 
 
 Sixth. Sea -weeds contain constantly considerable iodine and 
 bromine; land -plants contain rarely any. But the compound of 
 these elements is mostly soluble, and therefore to a great extent 
 washed out of the coal before we get hold of it ; still several chem- 
 ists have proved the presence of iodine in the ashes of stone - coal, 
 and Mohr has lately succeeded in finding even bromine in the coal. 
 
 That finally the sea -weeds are a sufficient cause for the produc- 
 tion of the vast coal-beds, need not here be proved; it will be 
 enough to state that even a single weed often measures hundreds of 
 feet in length, being provided with branches and leaves of corre- 
 sponding magnitude ; that these weeds abound in all seas ; that they 
 necessarily sink to the bottom when they die, and thus decaying 
 under water, must form a carbonaceous mass ; that finally peat - bogs 
 are small as compared to large forest regions, and that again these 
 are insignificant when compared to the vast fields of sea - weeds well 
 known to mariners — fields of truly continental magnitude ? While 
 on the soil only a limited amount of combustible can be accumulated, 
 there is no limit to this accumulation in the deep. 
 
 While thus the chemical nature of stone - coal proves that it never 
 could have resulted from vascular plants or land plants, that is, 
 plants essentially made up of woody fibre, and furthermore, that 
 the chemical nature of stone - coal exactly harmonizes with that 
 resulting from sea - weeds ; while further, no land vegetation is ade- 
 quate to account for the thickness and the extent of the stone - coal 
 fields of the world, and particularly for those of the Mississipi 
 Valley, requiring a vegetation as immense, as uniform and persis- 
 tent as that of the sea - weeds of the ocean ; while considering all 
 this we have purposely omitted to refer to the uniformity in the 
 strata, the regular interposition of marine rocks among the coal- 
 beds, the accompanying fossils, etc. On these grounds Mohr's theory 
 
REPORT OF STATE GEOLOGIST. 231 
 
 is also infinitely superior to the commonly accepted one ; for not all 
 ttinkers are ready to clothe the earth with a more luxuriant growth 
 than now is observed ; nor have we a ready command over the 
 creeping centuries ; nor have we ever seen vegetable debris piled 
 up in sufficient quantity to form a coal - bed. Geologists are taking 
 a little more care of the crust of the earth of late ; they are not 
 quite so ready now, as formerly, to assume that a vast region of land 
 emerged about a hundred times out of the ocean, and sank again. 
 
 The very water in the sea, in the constitution of the air it con- 
 tains, gave Mohr a convincing proof of the continuous formation of 
 coal at the bottom of the ocean, even in our day. 
 
 In the preceding I have given a short synopsis of some points of 
 Mohr's theory of the formation of coal ; it rests throughout upon 
 well - recognized facts, does not require nature to work otherwise 
 than as we now observe her working, and instead of ignoring the 
 chemical nature of the coal whose origin we wish to discover, it actu- 
 ally made the investigation of this constitution the starting-point. 
 
 For Iowa, this theory has a very great importance ; for if the older 
 theories are true, then we need hardly expect coal underlying the 
 rocks in the more central parts of the basin ; but if Mohr's theory 
 is true, then the coal will extend over the whole of this field. For 
 this reason — and also because this theory seems hardly yet known 
 in America — I have deemed it not improper to give a short synopsis 
 of the same. 
 
 My owii investigation of the Iowa coals has added four more not 
 unimportant proofs to the theory in four facts which can not possibly 
 be accounted for by the old fanciful views. 
 
 The first of these facts is the great uniformity in the composition 
 of a coal - bank over quite a considerable area. 
 
 The second is the fact that the upper parts of our Iowa coal - banks 
 contains the most pyrites ; the lower parts being very often entirely 
 free from this substance. The sulphuretted hydrogen set free in the 
 carbonizing sea- weeds escapes upward; in meeting the ferruginous 
 waters, pyrites would result, so that these latter would prrdominate 
 in the upper parts of the resulting coal-bed. 
 
 The third consists in the investigation of the fibrous portions often 
 met ,with in our Iowa coals. These portions look and feel precisely 
 
232 EEPORT OF STATE GEOLOGIST. 
 
 like charcoal ; retain a distinct fibrous structure. By analysis of the 
 same I found them to contain but very little of bitumen, as compared 
 to the closely adjoining coal; and saw, that even after protracted 
 exposure to white heat, they retained their structure ; indeed, the 
 coked mass looked precisely as the fibres did before coking, while 
 the coal, wherein they were imbedded, was highly baking. 
 
 This shows plainly that the woody fibre irregularly distributed in 
 small portions through some of our Iowa coals never lost its peculiar 
 structure, but merely was charred ; that the entirely different sub- 
 stance forming the bulk of our coal, therefore originally also must 
 have been entirely different from these fibrous plants. Of quite par- 
 ticular interest is the fact, that while this fibrous coal upon drying 
 deported itself like other vascular fuels, (wood, etc.,) the mass all 
 around it increased in weight, as I shall now explain. 
 
 Fourth. By very careful working I discovered that all our Iowa 
 coals, after having lost their moisture, commenced upon further dry- 
 ing at a temperature a little above that of boiling water, to increase 
 in weight, an increase sometimes amounting to fully two or more per 
 cent. Prof. Whitney had noticed this in some cases ; in another 
 place I have shown how he came to miss the general law. This' same 
 property I have also discovered in cannel coal from England, and 
 stone - coal from Silesia, so that I consider it a property common to 
 all stone - coals. Neither peat, nor brown coal, nor bituminous wood, 
 did as yet show this peculiar increase in weight ; so that this 
 property must be considered a new distinctive property peculiar to 
 stone - coal. It forms therefore an additional impossibility concern- 
 ing the old theories of coal, and a new link in the chain of facts on 
 which the chemical theory of Mohr rests. 
 
 Coal, true stone - coal, was not restricted to a particular period in 
 the earth's history, but it is forming even at the present day in the 
 oceans. 
 
CHEMICAL REPdET ON THE AYATER AND ROCKS OF THE STATE. 
 
 CHAPTER II. 
 
 THE WATER. 
 
 We are very apt to consider the rocks as permanent, and yet they 
 are continually changing. The principal cause of this change is the 
 moving water in the rocks. When it slowly washes solid matter out 
 of the rocky strata, the land may be gradually sinking and more 
 sudden changes felt over a large extent of territory as an earth- 
 quake, may follow; we might here refer to the earthquake which was 
 felt sometime last spring, over a great portion of the Northwest, 
 after a particularly wet season. 
 
 To understand the change of the rocks and to investigate their 
 original formation it, therefore, is necessary to carefully analyze the 
 waters they contain. The more direct demand of people possessing 
 mineral springs, thus meets a scientific necessity, in requiring careful 
 analyses of the waters of the State. 
 
 During the former geological survey no waters were analyzed. 
 My proximate analyses of the water of the artesian well at Mt. 
 Pleasant (summer 1865) together with an accurate analyses of the 
 water of a spring near the same place, made by me at the order of 
 Dr. Mark Ranney early in 1866 were the only two analyses of Iowa 
 waters executed previous to the present survey. 
 
 The most important of the waters yet analyzed is that of the 
 artesian well at Mt. Pleasant, on the ground of the Iowa Hospital 
 for the Insane. The State Geologist procured about six gallons of 
 the water in order to enable me to make a complete analysis of the 
 same. Of this water I have used two gallons this fall to determine 
 the proportion of these substances which are present in considerable 
 quantities. The remaining water will be used in order to determine 
 30 
 
234 
 
 EBPORT OF STATE GEOLOGIST. 
 
 those substances which are present in very small quantities. In the 
 bottles I noticed a very fine crystalization of dolomite. This fact is 
 of considerable importance, as it shows that such waters, by perco- 
 lating the limestone, may gradually change them altogether into 
 dolomities. For the sake of comparison I take the liberty to make 
 use of the analysis of the Mt. Pleasant spring water, although this 
 analysis is not the property of the survey. 
 
 LOCALITIES OF THE WATERS. 
 
 The waters analyzed as yet were nearly all from the First Con- 
 gressional District. They are in the mineralogical collection of the 
 survey, designated by the following numbers inscribed on the labels : 
 
 No. '24. Mineral spring, on S. D. Well's farm, on section fifteen, 
 township seventy, range thirteen, near Bloomfield, Davis county. 
 
 No. 72. Salt spring, from the largest salt spring at the crossing 
 of Salt creek and the Bloomfield road, in the northeast portion of 
 Davis county. 
 
 No. 114. Artesian well, Mt. Pleasant, Henry county ; depth of 
 boring, 1,125 feet; temperature of the water (November 6, 1866,) 
 62° F., while the common well showed only 55° F. — [White.] 
 
 No. 120. Water from the Ottumwa school well, sent by Dr. 
 Warden. 
 
 No. 460. Well on Kinersly's farm, one mile from Keosauqua, 
 Van Buren county. 
 
 The total amount of mineral matter in these waters is very differ- 
 ent. In order the better to understand these relations, I add a few 
 determinations of other waters. All figures refer to 10,000 parts of 
 water : 
 
 WATER. 
 
 Croton water, New York 
 
 IOWA WATERS. 
 
 Spring Water, Mt. Pleasant 
 
 Kinersly's well, Van Buren county 
 
 Wells' spring, Davis county 
 
 Artesian well, Mt. Pleasant 
 
 Salt spring, Davis county 
 
 School well, Ottumwa 
 
 OTHER WATERS. 
 
 Congress spring, Saratoga, IST. Y 
 
 Ocean (mean of several hundred analyses) 
 Salt well, Luneberg, Prussia 
 
 SALTS. 
 
 BV WHOM ANALYZED. 
 
 1.0 
 
 BUliman v .. 
 
 3.5 
 
 Hinrichs 
 
 10.9 
 
 Hinrichs i 
 
 24.4 
 
 Hinrichs 
 
 25.3 
 
 Hinrichs ; 
 
 29.7 
 
 Hinrichs 
 
 39.5 
 
 Hinrichs 
 
 49.6 
 
 Schweitzer 
 
 344 
 
 Forchhammer 
 
 2500 
 
 Forchhammer 
 
 460 
 24 
 
 114 
 72 
 
 120 
 
REPORT OF STATE GEOLOGIST. 235 
 
 Tbi^ latter is one of the most nearly saturated brines known. It 
 is evident that salt spring No. 72 is exceedingly sweet as compared 
 to the Luneburg well. One of the poorest brines used is that of 
 Salzhausen, Germany, containing about 120 parts of salts to 10,000 
 water, or about four times as much as our salt spring ; and even the 
 former brine is only worked by making use of the refuse coal from 
 a coal mine at the same place. In the United States, salt is too 
 abundant that such wells could be utilized. 
 
 NATURE OF THE MINERAL MATTER. 
 
 In the salt spring (No. 72) and well spring (No. 24), common salt 
 dominates over the other mineral ingredients ; yet both waters con- 
 tain a considerable amount of sulphuric acid. In the Ottumwa well 
 (No, 120) and Kinersly's (No. 460), iron abounds ; they are almost 
 vitriolic waters, and altogether unfit for use. The mineral matter 
 of the Ottumwa well was found to consist of — 
 
 Eerruginous sediment in the bottle 10.2 
 
 Gypsum 10,4 
 
 Ferric sulphate, common salt, etc 18 9 
 
 Total in 10,000 water. 39.5 
 
 The spring at Mt. Pleasant contains principally calcium carbonate 
 (65 per cent of all salts) ; the artesian well water is characterized 
 by the predominance of sulphates ; (84 per cent of all its salts are 
 sulphates). These two waters having been accurately analyzed, it 
 may be interesting to report the final result, showing the various 
 mineral ingredients for 100,000 parts of water. 
 
 ARTESIAN WELL AND SPRING- WATER, MT. PLEASANT. 
 
 The mineral constituents of waters are given first : the elements 
 separately; second, these combined to bases and acids; third, the 
 same estimated as salts. Now, neither the second nor the third 
 method is quite exact, since we do not positively know how the 
 elements really are combined ; so that the first mode of stating the 
 results seems to be the safest. Nevertheless, it has hardly come 
 into use, and for some practical applications the third statement is 
 the most convenient. 
 
236 
 
 REPORT OF STATE GEOLOGIST. 
 
 IN TEN THOUSAND "WATER. 
 
 ELEMENTS. 
 
 SPBIKG. 
 
 ART. WELL. 
 
 BATIO. 
 
 I. METALS. 
 
 Sodium " . 
 
 0.013 
 0.063 
 0.900 
 
 0.028 
 0.409 
 0.020 
 1.735 
 
 4.585 
 0.630 
 2.750 
 
 4.876 
 3.305 
 1.200 
 10.974 
 
 353 
 
 Magnesium . 
 
 1.7 
 
 Oalpium - 
 
 3.0 
 
 n. NOInT- MET ALIO ELEMENTS. 
 
 174 
 
 
 0.76 
 
 Chlorine 
 
 60 
 
 Oxvffeii . 
 
 6.3 
 
 
 
 Total 
 
 3.47 
 
 25.32 
 0.40 
 
 7.3 
 
 Sediment in flasli 
 
 
 The ratio in the last column is obtained by dividing the figures 
 under artesian well by those under spring ; or the ratio expresses 
 how many times tlie water of the artesian well contains the amount 
 of the elements in the spring water. If the elements were present 
 in both of these waters in the same proportion, then 7.3, the ratio 
 of the totals, would be the ratio for the several elements also. In 
 fact, only the ratio for oxygen approaches to this ratio; all others 
 differ very much from 7.3, &c. The ratio for sodium, sulphur and 
 chlorine are particularly great ; or in words, the water from the deep 
 (artesian) well contains proportionally much more of sodium, sulphur 
 and chlorine, than the water from near the surface (spring). The 
 two waters, both from the same place, but from very different 
 depths, therefore differ very much, not only in the total amount of 
 mineral matter, but even more so in regard to the quality of the 
 same. 
 
 IN TEN THOUSAND OP WATER. 
 
 
 SECOND — Binaries. 
 
 SPEING 
 
 AET. 
 WELL. 
 
 Common salt 
 
 0.33 
 0.07 
 1.50 
 1.26 
 0.605 
 
 1.97 
 
 Sulphuric acid • 
 
 13.19 
 
 Carbonic acid 
 
 1.13 
 
 Lime ^ 
 
 3.85 
 
 
 1.05 
 
 Soda 
 
 5.14 
 
 
 
 
 TniRTi— Salts. 
 
 Sodium chloride (common salt) 
 
 Sodium sulphate (glauber salt) 
 
 Magnesium sulphate (epsom salt) 
 
 Calcium sulphate (gypsum) 
 
 Calcium carbonate (calcite) 
 
 Magnesium carbonate (magnesia alba) . 
 
 0.33 
 "0.21 
 
 2.250 
 (1.975 
 
 1.97 
 
 11.77 
 
 3.15 
 
 5.86 
 
 2.55 
 
KEPORT OF STATE GEOLOGIST. 
 
 237 
 
 The names in parenthesis are added for those of the readers who 
 may not be familiar with the names of the salts. 
 
 The amount of salts even in the artesian well may appear insig- 
 nificant — only about one - fourth of one per cent ! But when larger 
 quantities of the waters are used, then these salts become plainly 
 manifest to everybody. The steam - engine at the Iowa Hospital for 
 the Insane is reported to have pumped the water for use at the rate 
 of ten thousand gallons an hour. This is more than eighty thousand 
 pounds an hour, and the insignificant amount of salts is more than 
 two hundred pounds per hour ! At that rate the following pounds of 
 the different salts would be brought up with the water each hour : 
 
 Lbs. 
 
 Common salt jg 
 
 Glauber salt : g^ 
 
 Epsom salt ' , . . ^ 35 
 
 Gypsum aad calcium carbonate g7 
 
 Or these salts would contain of 
 
 Sulphur 39 
 
 Carbon 3 
 
 Chlorine gas ; 10 
 
 Magnesium metal 5 
 
 Calcium metal , 23 
 
 Sodium metal 37 
 
 In the course of ten hours these salts would amount to a ton ! 
 Only a small amount of these used in a boiler would quickly produce 
 a thick incrustation ; the sulphates would remain pretty long in solu- 
 tion, so that a pretty concentrated brine might result — all of which 
 has been so abundantly experienced that the water is no longer used 
 for such purposes. In the proximate analysis of 1865 the chlorine 
 was not determined. By my recent careful and complete analysis 
 recorded above, it is seen that there is plenty of chlorine, which, in 
 the presence of sulphuric acid and some free carbonic acid, may set 
 free the corroding vapors of hydrochloric acid. 
 
 I intend to subject this water to still more scrutinizing analyses ; 
 then, together with the investigations of the specimen rock from the 
 boring, the boiler deposits, the corroded iron tubes, and the surface 
 water from the same place will form a whole of well ascertained facts 
 for various levels from the surface to a depth of one thousand one 
 
238 REPORT OF STATE GEOLOGIST. 
 
 hundred and twenty - five feet, which I hope will lead to some general 
 results. 
 
 One very interesting general result may already here be pointed 
 out. If we calculate the per centage of the various salts in the two 
 waters, we find : 
 
 SALTS. 
 
 FEB CENTAGE. 
 
 Spring. lArt'n Well. 
 
 Sodium sulphate 
 
 Sodium chloride.... 
 Magnesium sulphate. 
 Calcium sulphate. .. 
 Calcium carbonate... 
 
 46 
 6 
 
 13 
 26 
 10 
 
 This shows a marked decrease in the proportion of the lime salts, 
 while the magnesium salts, and particularly the alkali, increase as we 
 descend below the surface. The surface -water is a calcareous car- 
 bonated water; the water from the deep is suiphated and alkali- 
 water. The latter are by far the most soluble of these salts ; and 
 this circumstance causes their accumulation in the deeper waters. 
 Quite a similar change our surface waters undergo in their course 
 toward the ocean. In the rivers there is but a small amount of 
 mineral matter, and the carbonates of lime and magnesia dominate; 
 both become less and less, both being deposited on the way to the 
 ocean, which, like the water from the deep well at Mount Pleasant, 
 only contains the most soluble salts. The more immediate cause of 
 this change in the rivers is the life of aquatic animals ; in the rocks 
 the same change is brought about by the constant metamorphosis of 
 the rock itself. 
 
 The preceding contains alhthe results ascertained in regard to the 
 waters of the State. Compared with what remains to be done, it is 
 very little ; but compared with what had been done previously it is a 
 good deal. So much is certain, a correct interpretation of the con- 
 stitution of the rocky framework of the State can only be obtained by 
 a careful chemical study of both the rocks and the waters they 
 contain. 
 
 ir. THE KOCKS. 
 
 The rocks of Iowa belong to only four kinds ; they are either 
 calcareous, arenaceous, argillaceous, or carbonaceous. To the first 
 
REPORT OF STATE GEOLOGIST. 239 
 
 belong limestones and dolomites, both efferrescing (at least) with hot 
 acids. They greatly dominate in the State. The finest arenaceous 
 rock of Iowa is the St. Peter's sandstone, exposed in the northeast- 
 ern corner of the State ; good sandstones are also found in the coal- 
 measures of Southern Iowa, and finely crystalized silicia, that is, 
 quartz, abounds in the geodes found near Keokuk and other places. 
 Shales are the most common representatives of the argillaceous 
 rocks, passing by the dark, more or less combustible varieties gradu- 
 ally into eoal, the most valuable carbonaceous rock of Iowa. Geo- 
 logically, coa,l is as much rock. as the limestone underlying the same, 
 or the sandstone above it ; it is found stratified like either of these 
 two rocks. 
 
 These four kinds of rock are composed of but six different chem- 
 ical elements. Three of these are metals, having, when pure, a 
 lustre peculiar to these bodies ; the other three are metalloids, being 
 devoid of such lustre. The three metals are calcium, magnesium 
 and aluminum, of which the last two are already quite frequently 
 used in the arts ;*magnesium, the metal contained in epsom salts, 
 being used for illuminating purposes, since it gives a most dazzling 
 light; aluminum, the metal of clay, remarkable for its beautiful 
 silver - like appearance and its excessive lightness, being not heavier 
 than pkper, is considerably used for certain alloys. Calcium has as 
 yet not found any application in the arts. About forty pounds in 
 every hundred pounds of pure limestone is calcium. 
 
 The three metalloids are oxygen, carbon and silicon. The first 
 constitutes about one - fifth of the air we breathe, and is really the 
 vital principle of the air ; in our rocks it is present in much greater 
 quantity than in the air, for it constitutes about one - half of all of 
 them (excepting coal). The second, carbon, is well known; in char- 
 coal we have it nearly pure. Silicon is very closely allied to the 
 former, sand being composed of silicon and oxygen in nearly equal 
 proportions. 
 
 The following table will give a correct idea of the elementary 
 composition of our Iowa rocks, by means of the per centage compo- 
 sition of the purest of each kind. The first three are very frequently 
 met with almost chemically pure, in crevices and openings in the 
 rocks, constituting crystals. In limestone we thus find calcite or 
 
240 
 
 BEPOKT OF STATE GEOLOGIST. 
 
 calcium carbonate in beautiful crystals. If the limestone contains 
 also the metal magnesium, we usually find the crystals to have a 
 peculiarly pearly lustre, and somewhat curved faces ; these crystals 
 are called dolomite. In arenaceous rocks we find under similar 
 circumstances the beautiful crystals of quartz. The other two rocks 
 hardly ever occur quite so pure as here given, except it be carbon as 
 diamond. These pure forms are the minerals corresponding to the 
 rock ; they are the rock purified by nature herself : 
 
 
 ELEMENTS. ' 
 
 
 MBTALOIDS. \ METALS. 
 
 KOCK AND CORRESPONDING MINERAL. 
 
 d 
 O 
 
 § 
 o 
 
 a 
 a 
 
 S 
 
 g 
 
 S 
 
 a 
 fan 
 
 i 
 
 a 
 
 a 
 
 CALCAKEOUS HOOKS. 
 
 Calcite 
 
 48. 
 53.3 
 
 53.3 
 
 50. 
 
 13. 
 13. 
 
 100. 
 
 46.7 
 35. 
 
 40. 
 31.8 
 
 
 
 Dolomite 
 
 13. 
 
 
 ARENACKOUS KOCK. 
 
 Quartz 
 
 
 AKGILLACE0TJ8 BOCK. 
 
 Clay, pure 
 
 .... 
 
 
 35. 
 
 CABSONAOEOUS KOCK. 
 
 Carbon, pure 
 
 In dolomite, which in the north of the State forms immense fields 
 contains one - fifth by weight of the metal magnesium ; if this is 
 separated, it burns with great splendor. We may now readily con- 
 ceive what an immense amount of heat and light has some time been 
 produced when those elements, that are now dormant and under our 
 feet, were still uncombined in the atmosphere, perhaps. Tolerably 
 pure limestone contains twelve per cent, dolomite about thirteen per 
 cent of pure coal ; every hundred feet of limestone contains enough 
 of pure coal to form a bank of anthracite of ten to twelve feet in 
 thickness. But all of this combustible, both metalic and carbon- 
 aceous, is now unavailable, since these elements are in the rock, 
 combined with oxygen ; that is they are burnt. The only exception 
 to this rule is the- coal ; for this reason it has so great economic 
 value. 
 
 The coal having been at length considered in the first chapter, I 
 
REPORT OF STA.TE GEOLOGIST. 241 
 
 may here limit myself to the calcareous rocks of the State. Neither 
 the arenaceous nor the argillaceous rocks have as yet been analyzed. 
 
 THE CALCAREOUS ROCKS OF IOWA. 
 
 The results of chemical analysis of these rocks, are usually 
 stated by the per centage of each of the proximate chemical com- 
 pounds contained in the same. But it is impossible even for an 
 expert to get a really precise idea of the constitution of such a rock 
 by the full, unreduced result of the analysis. It is as diflScult as to 
 obtain an idea of the value of a yum of money consisting of all the 
 various coins of quite a number of nations. This will become much 
 easier by referring these various coins of each nation to one unit as 
 a standard. 
 
 Now, this is what I have done for the analysis of Iowa rocks, 
 made by Professor Whitney during the former survey ; and in the 
 same way I give the final result of my own analysis of the rocks. 
 I refer the composition to the per centage of the mineral species 
 which undoubtedly make up the rock. The preceding was intended 
 to convey a definite idea of what the species are for our State ; and 
 as the non - calcareous rocks also are insoluble, we unite under the 
 heading insoluble the arenaceous and argillaceous part of the rocks 
 under one. Whenever some other matters, like moisture, soluble 
 iron compounds, or alkalies are determined, I sum these up under 
 the heading " others." The character of the rock thus is always 
 essentially given by only three figures, viz. : the per centage of the 
 insoluble, of the calcite, and of the dolomite in the same; the 
 " others " spoken of are only present in small proportions. 
 
 As an example^ I give my reduction of two of Whitney's Analyses : 
 
 LOCALITY. I Calcile. I Dolomite. llnsoJuble. I Others. 
 
 Le Claire, bcott County 3.69 
 
 Rock Island, Illinois 98.55 
 
 88.69 
 0.58 
 
 6.70 
 0.42 
 
 0.80 
 
 These two localities are only about twelve miles distant ; the above 
 statement shows at a glance, that the rock at LeClaire approaches to 
 a pure dolomite, while at Rock Island it is still nearer a pure calcite 
 (carbonate of lime, or calcium carbonate). 
 31 
 
242 REPORT OF STATE GEOLOGIST. 
 
 In order to show the advantage of this form over the one com- 
 monly used, I transcribe Prof. Whitney's statement from the report, 
 for the Le Claire rock : 
 
 Silica and insoluble silicates 6.70 
 
 Peroxid of Iron and a little protoxide 0.80 
 
 Lime , 29.06 
 
 Magnesia , 19.33 
 
 Soda 0.11 
 
 SXILPHURIC ACID AND CHLOKINE — MINUTE TRACES. 
 
 Carbonic acid 43.65 
 
 Loss 0.46 
 
 This is the direct result of analysis ; it is the grain in the ear, and 
 in order to become digestible, I have subjected it to a little grinding, 
 ■which reduced the complicated statement to but three essential 
 figures, viz : 
 
 Per cent. 
 
 Calcite 3.69 
 
 Dolomite 88.69 
 
 Not calcareous 7.50 
 
 If the reader only will take the trouble to get a clear idea of the 
 terms calcite and dolomite — which I trust may be obtained from the 
 introductory lines — the constitution of the calcareous rocks of Iowa 
 will become intelligible. 
 
 The geologist represents the result of his exploration of a given 
 field by sections, showing the succession and super -position of the 
 various beds of rock. These sections are either horizontal, showing 
 the surface - formations in a given direction, or they are vertical, rep- 
 resenting the order and thickness of the rocks one above the other. 
 
 It is evident that not until we are able to give a sufficient number 
 of chemical sections, both horizontal in all directions throughout the 
 State, and also vertical sections of a considerable and well - selected 
 number of localities, not until then can it be said that we really know 
 the nature of the rocks of the State. It is upon the chemical con- 
 stitution of the rock that the practical application of the same for 
 the various purposes depends ; it is by the chemical composition that 
 the mineral riches of the rocks are influenced ; and it is the chemical 
 composition of the rocks which determine, to a great extent, the 
 nature of the soil resting on top of it. 
 
REPORT OP STATE GEOLOGIST, 
 
 243 
 
 It is impossible to represent such chemical sections without proper 
 vrood cuts. In the absence of these, the numbers from which such 
 sections are drawn will here be given in a few tables. 
 
 In the following tabular sections I insert between each two sam- 
 ples the distance in miles between the places where the rock was 
 taken; these distances are evidently much too great, showing 
 that a great many more analyses will have to be made before the 
 rocks of the State can be said to be tolerably well known : 
 
 MISSISSIPPI SECTION. 
 EESULTS CALCULATED PROM WHITNEr'S ANALYSES. 
 
 OOtiNTT. DISTANCE. CALCITB. DOLOMITE. INSOL. OTHERS, 
 
 McGregor. . . . [river. 
 Dubuque,150ft.above 
 Hickory Grove.. 
 
 Le Claire 
 
 Business Corner. 
 Rock Island 
 
 ulayton . . 
 
 37 miles . . 
 
 0.63 
 
 9841 
 
 0.96 
 
 Dubuque.. 
 
 31 miles . . 
 
 ex. Mag. 
 
 95.59 
 
 2.46 
 
 Jackson. . . 
 
 44 miles . . 
 
 3.34 
 
 97.83 
 
 0.90 
 
 Scott 
 
 13 miles . . 
 
 3.69 
 
 88.69 
 
 6.70 
 
 Van Buren 
 
 90 miles . . 
 
 90.87 
 
 4.18 
 
 57 
 
 Illinois 
 
 
 
 98 55 
 
 0.58 
 
 0.43 
 
 80 
 
 The calcareous rocks along the Mississippi are therefore nearly 
 pure dolomite above Rock Island, and nearly pure limestone below 
 this place. That such is the case, is not new, but no previous state- 
 ment of these analyses enabled people not instructed in the secrets 
 of chemical analyses to see it so plainly as the above figures show it. 
 
 If we disregard the insoluble part of the rock, then we may 
 express the ratio between the amount of dolomite and calcite, by one 
 figure alone ; the above section then becomes : 
 
 PLACE. 
 
 COUNTY. 
 
 RATIO. 
 
 
 Clayton . . 
 Jackson. . . 
 
 Scott 
 
 Illinois . , . 
 Van Buren 
 
 156.00 
 
 
 43.00 
 
 
 34.00 
 
 
 0.006 
 
 Business Corner 
 
 0.04 
 
 Showing in a still more simple and more precise form the remark- 
 able fact of the diminution of dolomite towards the south. In Clay- 
 ton county the rocks contain 156 parts of dolomite to one of calcite; 
 in Jackson only 43 ; in Le Claire only 24 ; below this but a few, or 
 even a fraction of one per cent of dolomite. This gradual decrease 
 of the magnesian ingredient (dolomite) in the rock has not before 
 been made so perspicuous as by this ratio : 
 
244 
 
 EEPORT OF STATE GEOLOGIST. 
 
 CEDAR RIVER SECTION. 
 RESULTS CALCULATED FKOM WHITNEY'S ANALYSES. 
 
 PLACE. 
 
 COUNTY. 
 
 distaucb. 
 
 .2 
 1 
 
 a; 
 
 '3 
 
 O 
 
 Dolomite. 
 
 1 
 
 O 
 
 s 
 
 t— 1 
 
 S3 
 O 
 
 8hell Rook Falls... 
 
 Independence 
 
 Rock Island 
 
 (Jerro Gordo 
 
 Buchanan 
 
 Illinois 
 
 80 Qiiles 
 
 100 miles — 
 
 3.0 34.50 7a.60 0.80 
 
 0.03 97.11 1.83 10 03 
 
 0.006 98.55 58 43 
 
 1.10 
 
 These rocks all belong to the same geological formation, but it is 
 seen that the amount of dolomite corresponding to one of ca!cite in 
 these rocks increases northward from Rock Island, both through 
 various formations, as along the Mississippi river and also in the 
 same geological formation, as in the direction of the Cedar river; 
 only the rate of increase in this latter section is not as great as in 
 the former. 
 
 The origin of these peculiar dolomitic rocks is still a mystery, 
 notwithstanding all that has been written on that subject, and we 
 can hardly wonder that it is so when we see that the real constitu- 
 tion of these rocks never before has been properly expressed. It is 
 only when a great fact is clearly recognized by itself, that we can 
 hope at all to account for it. 
 
 SECTION FROM JOHNSON COUNTY TO FREMONT COUNTy. 
 RESULTS CALCULATED FROM MY OWN ANALYSES. 
 
 I^i 
 
 LOCALITY. 
 
 
 
 
 
 g5 
 
 <v 
 
 
 
 
 
 
 
 COUNTY. 
 
 DISTANCE. 
 
 d 
 
 (U 
 
 B 
 
 ^ 
 
 s 
 
 
 
 
 o 
 
 o 
 
 o 
 
 
 
 S3 
 
 K 
 
 03 
 
 o 
 
 o 
 Q 
 
 
 .— lo 
 
 5 
 
 10 Clark's Mill, Iowa City. . i Johnson ..|140 miles. 
 246 Section 30, township 73,1 
 
 I range 28 [Union. ... '90 miles 
 
 133|Three miles above Plum | 
 
 I Hollow 'Fremont.. I .... 
 
 0.00,96.50 
 
 0.0081.45 
 
 0.006 194.81 
 
 3.50 . . 
 
 trace 
 6.68 
 
 13,38 
 3.65 
 
 5.27 
 1.84 
 
 So that the calcareous rocks in Southern Iowa are almost pure 
 limestones (calcite). 
 
 Besides these sections, based upon quantitative determinations, 
 qualitative analyses have been made sufficient to determine the nature 
 of the calcareous rocks in two more sections in southern Iowa. The 
 presence of dolomite in a rock is usually characterized by a peculiar 
 
REPORT OF STATE GEOLOGIST. 
 
 245 
 
 aspect, due to small, crystaline, reflecting spangles in the rock. The 
 State Geologist, judging from the appearance of the rocks in south- 
 western Iowa, concluded the absence of dolomite in the same ; the 
 following, analyses will show that- he was right, or that the calcareous 
 rocks of this region of this State, mostly belonging to the upper 
 coal - measures, are indeed very nearly devoid of dolomite. 
 
 CHEMICAL SECTION — FIRST TIER OF COUNTIES. 
 
 ■3 rf 
 
 LOCALITY. 
 
 DIS- 
 TANCE. 
 
 COUNTY. 
 
 PEB CENT 
 DOLOMITE. 
 
 ^49 
 
 
 70 miles. 
 70 miles. 
 
 
 
 ^v 
 
 
 Page(Qorth part).. 
 Fremont 
 
 "F^rftTnnnf, 
 
 Faint trace. 
 
 135 
 
 Wilson's quarry, 3 miles above 
 Plum Hollow 
 
 Faint trace. 
 
 133 
 
 Wilson's quarry, 3 miles above 
 Plum Hollow 
 
 
 0.63 
 
 
 
 
 CHEMICAL SECTION — THIRD TIER OF COUNTIES. 
 
 10 
 
 253 
 
 108 
 
 83 
 
 84 
 
 77 
 
 85 
 
 91 
 
 118 
 
 Coral Mills, near Iowa City 75 miles. 
 
 Coral Mills, near Iowa City 75 miles. 
 
 Pella 57 miles. 
 
 No. 9 of Winterset Section 13 miles. 
 
 No. IS of Winterset Section. 13 miles. 
 
 Above building layer 44 miles. 
 
 Building layer. . .'. 44 miles. 
 
 Lewis 34 miles. 
 
 Merretl's quarry, 6 miles north of 
 Council Bluffs 
 
 Johnson 
 
 Johnson 
 
 Marion 
 
 Madison 
 
 Madison 
 
 Madlson(west line.) 
 Madison (west line.) 
 Cass 
 
 None 
 
 None 
 
 None 
 
 Trace 
 
 Trace 
 
 Trace 
 
 Trace 
 
 Faint trace. 
 
 Pottawattamie iFaint trace. 
 
 The preceding embraces all the systematic knowledge of Iowa 
 Rocks hitherto brought to light. I hardly need to say that it is 
 very little positive knowledge for ao vast a field ! The chemical 
 sections run are few in number, and the point really determined in 
 these few lines, are very far apart. In this field very much remains 
 to be done. 
 
 An artesian well 1,125 feet deep, has been bored at Mount 
 Pleasant, Henry county, for the Iowa Hospital for the Insane. A 
 very complete set of the borings has liberally been presented to the 
 State University. Of these I have analyzed the following nine 
 portions, corresponding to the depth indicated, thus giving us some 
 fixed points in an admirable verticle section of the Iowa rocks, of 
 more than a thousand feet. 
 
2i6 
 
 REPORT OF STATE GEOLOGIST. 
 VERTICAL SECTION AT MT. PLEASANT. 
 
 
 CHARACTER OF CALOARBOUS 
 ROCK. 
 
 Ratio. 
 
 Calcite. 
 
 Dolom- 
 ite. 
 
 Insolu- 
 ble. 
 
 Others. 
 
 160 
 300 
 300 
 400 
 500 
 600 
 718 
 990 
 1095 
 
 Dolomitic limestone 
 
 Magnesian limestone 
 
 Calcareous dolomite 
 
 Calcareous dolomite 
 
 Calcareous dolomite 
 
 Calcareous dolomile 
 
 Nearly pure dolomite 
 
 Nearly pure dolomite 
 
 Magnesian dolomite, infinite. 
 
 0.5 
 
 30.07 
 
 15.32 
 
 48 74 
 
 0.03 
 
 75.70 
 
 2.30 
 
 20.38 
 
 1 .8 
 
 6.37 
 
 11.21 
 
 79.96 
 75.16 
 83.88 
 
 2.1 
 
 '2.93 
 
 6.35 
 
 3.3 
 
 12 34 
 
 27.29 
 
 59.14 
 
 36.0 
 
 1.16 
 
 3017 
 
 66.79 
 
 38.1 
 
 2 39 
 
 64 40 
 
 27.19 
 
 
 
 
 82 69 
 
 6 26 
 
 5.35 
 1.76 
 5.22 
 4.78 
 7.98 
 1.87 
 
 5.98 
 0.06 
 
 One thousand one hundred and five feet were, by the Geologist, 
 supposed to correspond with the Hudson shales which outcrop 
 near Dubuque. From Mount Pleasant to the direction of the out- 
 crop of these shales in northeastern Iowa is nearly one hundred 
 and ten miles. The vertical thickness of rock of one thousand one 
 hundred feet at Mount Pleasant thus corresponds to one hundred 
 and ten miles in a horizontal direction at right angles to the line of 
 outcrop ; or one mile in a horizontal direction northeast from Mount 
 Pleasant corresponds to ten feet in the vertical direction at Mount 
 Pleasant. On Hall's geological map of Iowa, the outcrop of the 
 dolomite (Le Claire limestone) is very nearly sixty miles distant from 
 Mount Pleasant ; accordingly it might here be mot at a depth of six 
 hundred feet. The above chemical section of the boring shows the 
 dolomite to be at seven hundred and eighteen feet ; so that we may 
 suppose the rocks to be very uniform in their extent below the sur- 
 face. A very noteworthy circumstance forms the regular increase 
 of the ratio ; the relative amount of dolomite is slowly increasing 
 from three hundred to six hundred feet, corresponding to a slow 
 increase in the surface rocks for a distance of thirty miles. Now 
 this is not observable in the Misissippi section ; but in the Cedar 
 river section a similar increase was noticed. Again, in the short 
 distance of twelve miles, between Rock Island and Le Claire, the 
 rock almost suddenly changes from pure limestone (calcite) to dolo- 
 mite ; then twelve miles would correspond at Molint Pleasant to one 
 hundred and twenty feet in depth ; and it must be a very striking 
 coincidence that my analyses find at a depth of six hundred feet 
 only a ratio of two, and about one hundred and twenty feet deeper 
 
REPORT OF STATE GEOLOGIST. 247 
 
 a sudden increase of this ratio to twenty • six. It may therefore be 
 considered as tolerably well proved by this chemical section that the 
 rock corresponding to Hall's so - called Le Claire limestone commences 
 at Mount Pleasant at a depth of very near seven hundred feet. 
 
 This fact is of great importance in regard to the dip of the coal- 
 bearing rocks of the State ; and for this reason I intend to analyze 
 still more of the borings of the artesian well at Mount Pleasant. 
 
 In conclusion, I would add, that the excess of magnesia in my 
 analysis of the sample from the depth of one thousand ninety -five 
 feet, corresponds to the excess of magnesia in Whitney's analysis of 
 the Dubuque dolomite. 
 
ON THE COMPOSITION, VALUATION AND PEOXIMATE ANALYSIS 
 
 OF IOWA COALS. 
 
 CHAPTER III. 
 
 The following two papers have appeared in the American Journal 
 of Mining, of New York, for November 30, December 28, 1867 and 
 January 4, 1868. 
 
 I. ON THE COMPOSITION AND VALUATION OF IOWA COALS. 
 
 Before entering upon the analyses of the numerous samples of 
 coal submitted to me by the State Geologist, Dr. C. A. White, I 
 carefully reviewed the analyses of Prof. Whitney, recorded in Vol. I. 
 of the Geology of Iowa. 
 
 Prof. Whitney has determined the proximate constituents of six- 
 teen samples of Iowa coal, and reduced the same to 212° F ; that is, 
 while excluding the moisture, he retains the ashes of the coal in his 
 final statement. 
 
 Thinking that the combustible part of the coal alone can be con- 
 sidered as the mineral, so that the ashes as well as the moisture 
 ought to be excluded as accidental and really injurious constituents 
 of the coal, I reduced the analyses of Whitney to the comDustible 
 = 100 ; the result of this reduction is given in a diagram, the scale of 
 which is 1 millimeter to each per cent (or 100 = 100""° =: 1 decimeter.) 
 The fixed part of the combustible we will call carbon, the volatile we 
 term bitumen. The figures at the lower line indicate the order in 
 which these analyses are recorded in the Geology of Iowa, Vol. I., 
 Part 1, pp. 397-415 (1858). 
 
REPORT OP STATE GEOLOGIST. 
 
 249 
 
 I regret that the diagram here referred to can not be printed in 
 this publication; I must, therefore, be satisfied by inserting the 
 table from which the diagram was constructed. 
 
 TABLE OF REDUCED RESULTS. 
 
 COMBUSTIBLB OF = 100. ASH BXTKA. AUALTSES OF PBOF. WHITNEY. 
 
 LOCALITY. 
 
 New Buflfalo 
 
 New Buffalo '.. 
 
 Rock Island 
 
 La Balls, lower seam ' 
 
 La Salle, upper seam 
 
 Hillsborough, Cox' bank 
 
 Hillsborough, Grail's bank 
 
 Farmington, two miles above. . . 
 
 Farmington, half mile from 
 
 lowaville 
 
 Business Corner 
 
 Fort Dodge, west bank of river. 
 Section 18, township 88, range 28. 
 
 ASH. 
 
 14 Section 13, township 88, range 28. 
 
 Eldora, Hardin county. 
 Newton, Jasper county. 
 
 Mean of all . 
 
 47.14 
 44.18 
 41.54 
 4196 
 43.59 
 47.17 
 41.14 
 44.53 
 42.16 
 45.55 
 45.18 
 46 58 
 44.92 
 45.94 
 45.01 
 48.38 
 
 44.00 
 
 25.76 
 
 10.27 
 
 1.34 
 
 7.11 
 
 13.91 
 
 4.05 
 
 2.56 
 
 6.87 
 
 7.94 
 
 4.42 
 
 8.47 
 
 7.93 
 
 9.22 
 
 33.44 
 
 10 80 
 
 6.30 
 
 A mere glance at this table shows thjtt the great difference between 
 these Iowa coals is due to this varying per centage of ashes, while 
 the per centage of the carbon and bitumen in the combustible remain 
 essentially the same in all the coals, deviating but little from the 
 mean of 
 
 BUumen II } Combustible = 100. 
 
 which mean is represented by the straight line A B in the diagram. 
 If, instead of comparing all the coals of Iowa, we limit ourselves 
 to the coals of any one county, the unitormity of the combustible 
 becomes still more apparent. 
 
 32 
 
 WEBSTER COUNTY. 
 
 
 
 WHITNEY. 
 
 HINEIOHS. 
 
 No. 
 
 Bitumen.! Ash. 
 
 Bitumen.,' Ash. 
 
 12 
 18 
 
 
 43.16 
 41.13 
 37.31 
 
 40.50 
 
 7.34! 
 
 8.44 
 
 18.19 
 
 46 58 
 44.93 
 45.94 
 
 45.82 
 
 7 92 
 9 33 
 
 14 
 
 
 33 94 
 
 
 Mean 
 
 
250 
 
 REPORT OF STATE GEOLOGIST. 
 
 The deviations from the mean values are, according to 
 
 No. 13. No. 13. No. 14. 
 
 Whitney +2.66 +0.63 -3.29 
 
 Hinrichs +0.76 —0.90 +1.12 
 
 Or, according to my reduction, the several samples differ hardly 
 more than the possible errors of the analyses. The proper com- 
 parison of those deviations we obtain by taking the sum of their 
 squares ; these are for Whitney's figures, 18.2966, for mine only 
 1.4020, or fully thirteen times less ! According to Whitney's state- 
 ment these three samples of coal from three different localities in 
 Webster county appear to differ by fully, six per cent in the amount 
 of bitumen ; according to my reduction there is only an extreme 
 variation of one and one - half per cent. 
 
 It is therefore manifest that by throwing out not only the moisture 
 (as Whitney has done), but also the ashes, as accidental, then these 
 coals, analyzed by Whitney, differ not more in regard to the com- 
 position of the combustible than the errors of the different analytical 
 determinations of the same sample of coal : 
 
 Of Illinois coal, analyzed by Whitney, we have the following : 
 
 
 Locality. 
 
 WHITNEY. 
 
 HINRICHS. 
 
 JNo. 
 
 Bitumen, i Ash. 
 
 Bitunien.l Ash. 
 
 3 
 
 
 41.03 
 39.17 
 37.39 
 
 39.20 
 
 1.12 
 
 6 64 
 
 12.21 
 
 41.54 
 41.96 
 43.59 
 
 42.03 
 
 1?4 
 
 4 
 
 
 711 
 
 5 
 
 La Salle, upper 
 
 18.91 
 
 which show the following deviations from the mean : 
 
 No. 3. No. 4. No. 5. 
 
 Whitney +1.83 —0.03 —1.84 
 
 Hinrichs .' —0.49 —0.07 +0.56 
 
 Dr. Blaney, Chemist of the Illinois survey, has analyzed thirteen 
 samples of coal from Mercer county, Illinois, which fully confirm the 
 uniformity of the combustible for that county, although the result, 
 as stated by him, show an apparent variation of 14 per cent (from 
 19.2 to 33.3) in the amount of bitumen ! ) [See Illinois Report, 
 1866, Vol. I, p. 276.] 
 
REPORT OP STATE GEOLOGIST. 
 
 251 
 
 
 MERCER COUNTY, 
 
 ILLINOIS. 
 
 
 No. 
 
 BLANBT. 
 
 HIMRICHS. 
 
 Bitumen. | Deviation. 
 
 Bitumen. 1 Deviation. 
 
 3 
 
 29.8 
 
 0.05 
 
 36.52 
 
 +0.12 
 
 4 
 
 28.6 
 
 —1.25 
 
 36.86 
 
 +0.46 
 
 5 
 
 33.4 
 
 +3.55 
 
 38.38 
 
 +2.98 
 
 6 
 
 81.2 
 
 +1.35 
 
 35.61 
 
 —0.89 
 
 7 
 
 30.8 
 
 +0.95 
 
 35.16 
 
 —1.24 
 
 8 
 
 19.2 
 
 —10.65 
 
 35.04 
 
 —1.36 
 
 9 
 
 30.8 
 
 +0.95 
 
 36.67 
 
 +0.27 
 
 10 
 
 30.0 
 
 +0.15 
 
 35.21 
 
 —1.19 
 
 11 
 
 81.2 
 
 +1.35 
 
 37.32 
 
 +0.92 
 
 12 
 
 32.2 
 
 +2.35 
 
 36.43 
 
 +0.03 
 
 13 
 
 31.2 
 
 +1.35 
 
 36.28 
 
 —0.12 
 
 Mean... 
 
 29.85 
 
 
 36.4 
 
 
 Slim of snna.rftR 
 
 140.41 
 
 
 15.64 
 
 Probab] 
 
 e error 
 
 2.50 
 
 
 0.83 
 
 
 
 
 The sum is, by my calculation, reduced to one - ninth, the probable 
 error to one - third, of what they are for Blaney's values ; and the 
 example No. 8, deviating fully 10 from Blaney's mean, shows only a 
 deviation of IJ according to my reduction. 
 
 These examples are deemed sufficient to prove that even over a 
 considerable area we may consider the relative proportion of carbon 
 and bitumen in our Western coals as constant. 
 
 Thereby these proximate analysis of coals acquire a new and more 
 important value ; for if the combustible part in the coals, compared 
 with one another, is of the same composition, its heating effect will 
 necessarily be the same for equal weights of combustible ; or, in 
 other words, the value of these coals will be proportional to the per 
 centage of this combustible in the raw coal. 
 
 Furthermore, the heating effect of two weights of different coals 
 will be the same if both contain the same amount of this combusti- 
 ble (say 100) ; the amount of moisture and ashes, calculated for 100 
 combustible and added to this will therefore be the caloric equivalent 
 of these coals, or represent such weights of the raw coal as will 
 produce the same heating effect, namely that of 100 pure combus- 
 tible. 
 
 Thus the coals, numbers twelve and fourteen, from Webster 
 County, Iowa, contain respectively 80.6 and 73.4 of combustible; 
 hence these figures express the value in cents of a weight of the 
 
252 
 
 REPORT OF STATE GEOLOGIST. 
 
 coal equal to one dollar's worth of pure combuatible ; furthermore, 
 the amount of moisture and ashes is per 100 combustible respec- 
 tively 24.1 and 36.3 : hence the caloric equivalents of these coals 
 would be 124.1 and 186.3, that is, it would require 124.1 pounds of 
 the former and 136.3 pounds of the latter, to produce as much heat 
 as 100 pounds of the pure combustible, free from ash and moisture. 
 
 This valuation of coals we believe as accurate as any other theo- 
 retical one in use ; and it has this advantage, that it needs no extra 
 work beyond that of the proximate analysis, which for many 
 reasons, ought never to be omitted. 
 
 To directly compare our valuation with that based upon the 
 reduction of lead, I may refer to the seven hundred analyses of 
 Austrian coals recorded in Jahrbuch der K. K. geologischen Reich, 
 sanstalt, Bd. X., Heft 3, Wien, 1859. Here we find six analyses of 
 coals from Mihalkovitz, in Moravia, by W. Mrazek, viz. : 
 
 
 Ashes. 
 
 Water 
 
 Combustible. 
 
 Lead reduced by 
 1 Goal.|l Combustible. 
 
 
 17.4 
 49 
 5.5 
 5.1 
 3.9 
 6.8 
 
 1.01 
 1.06 
 118 
 0.89 
 1.03 
 0.08 
 
 81.59 23.99 
 
 39 40 
 
 
 94.04 
 93.33 
 94.01 
 9608 
 93.13 
 
 28.35 
 27.18 
 38.45 
 37.58 
 37.31 
 
 30.17 
 
 2 Bank 
 
 29.18 
 
 3 Bank 
 
 4 Bank 
 
 80.37 
 38.70 
 
 5 Bank 
 
 29.16 
 
 
 37.13 
 
 29.47 
 
 
 
 
 
 The deviations from the mean are, according to the reductions of 
 Mrazek, —3.14 +1.22 +0.05 +1,32 +0.45 +0.08 
 Hinrichs, — 0.07 +0.70 —0.34 +0.80 —0.77 —0.31 
 
 Of which the latter are all very much smaller than the former, 
 and hardly surpass the deviations between different determinations 
 of the same sample. Practically, one hundred of the combustible 
 matter in any of the above coals reduced the same amount of lead 
 (29.5 parts). 
 
 If we, therefore, calculate the caloric equivalent from the per 
 centage of combustible matter in these coals, as shown above, and 
 divide this by the equivalent determined by the lead - reduction, we 
 ought to get the same quotient always. I find this quotient to be 
 respectively 
 
 12.63 12.96 12.75 12.97 12.53 12.63 
 of which the mean is 12.74. 
 
REPORT OP STATE GEOLOGIST. 
 
 253 
 
 Dividing my equivalents of these coals, or respectively 
 122.6 106.3 107.2 106.4 105.5 ' 107.4 
 
 by this quotient 12.74 we ought to obtain the same equivalent as 
 directly determined by Mrazek; we find the equivalents : 
 
 
 OBSERVED. 
 
 OALCDLATED. 
 
 DIFFBRENOB. 
 
 1 Bank, upper 
 
 9.7 
 8.2 
 8.4 
 8.2 
 8.4 
 8.5 
 
 9.72 
 8.34 
 8.41 
 8.35 
 
 8.25 
 8.43 
 
 —0.08 
 
 1 Bank, lower 
 
 + 0.14 
 + 0.01 
 
 + 0.15 
 —0.13 
 
 2 Bank 
 
 3 Bank 
 
 4 Bank 
 
 5 Bank 
 
 —0.07 
 
 
 
 It thus appears that the extra reduction determination of Mrazek 
 was superfluous, for the comparison of the value of these coals ; 
 for my equivalent calculated from his proximate analysis fully agrees 
 with the equivalent directly determined by him. 
 
 The preceding is determined sufficient to warrant the following 
 deductions : 
 
 1. The ashes as well as the moisture of coals are to be con- 
 sidered as impurities, the combustible part being the real mineral 
 species. 
 
 2. This combustible part of our Western coals is very uniform in 
 composition, even for considerable parts of the coal - field. 
 
 3. For such portions of the coal field the value of the coal is 
 measured by the per centage of combustible, and 
 
 4. The caloric equivalent, that is, the number of pounds of coal 
 having the same heating efi"ect as 100 of the pure combustible, is 
 obtained by the proportion 
 
 Equivalent : 100 = 100 : value. 
 Or by dividing the value into 10,000. 
 Having completed an extensive series of analyses of coals from 
 Iowa, conducted according to a uniform method, the result of a 
 special series of experiments, I am in the position to add to this 
 notice, that not only the general uniformity over considerable areas 
 is confirmed, but the change in this composition in the various parts 
 of the coal-field seems to lead to still more general results. 
 
 Thus by comparing the Iowa coals with those of Illinois, analyzed 
 
254 REPORT OF STATE GEOLOGIST. 
 
 by Prof. Blaney, I find, after reducing these latter analyses, that in 
 the Illinois coal - field the per centage of bitumen appears to increase 
 ■westward. For I find, as means, for 
 
 NO. OP 
 ANALYSES. 
 
 LOCALITT. 
 
 PEE CENT 
 BITUMEN. 
 
 16 
 
 Grundy county, Illinois 
 
 La Salle county, Illinois 
 
 Marshall county, Illinois 
 
 Warren and Mercer counties, Illino s.. 
 
 33 
 33 
 35 
 36 
 
 These analyses, all executed by Prof. Blaney, may be considered 
 comparable. So also the following analyses of Prof. Whitney, given 
 above. 
 
 No. 3, 4, 5 Illinois Mean 43 per cent bitumen. 
 
 The other 13 Iowa Mean 44 per cent bituncen. 
 
 From my own analyses, recorded in Chapter I, Section 4, it 
 appears that westward in the Iowa coal - field, the amount of bitumen 
 again decreases (about 4 per cent.) 
 
 I As far as the facts in regard to this very important question are 
 known, it seems that the greatest amount of bitumen is found in that 
 part of ihe coal -field near the course of the Mississippi, and that also 
 on the whole the amount of bitumen is greater for Iowa coals than for 
 Illinois coals. (See American Journal of Mining, Feb. 1, 1868.) 
 
 n. ON THE PROXIMATE ANALYSIS OF COALS. 
 
 Coal is not a simple chemical combination, expressible by a chem- 
 ical formula ; but it is the final residuum of vegetable matter having 
 been exposed to a long - continued and complex process of addition 
 and subtraction. An elementary analysis will therefore not teaCh 
 us much in regard to the nature of the combustible ; for who would 
 dare to make any conclusion concerning the peculiar combination of 
 the elements thus determined? Even the heating efi'ect calculated 
 from this elementary analysis is not more trustworthy than the val- 
 uation by the reduction of lead. 
 
 The proximate analysis, on the contrary, enables us to learn some- 
 thing in regard to the real nature of the fuel. The moisture and 
 the ashes are both hot only diluents of the fuel, but in themselves 
 obstacles to the efi'ectiveness of the same ; the vaporization of the 
 moisture causes a serious loss of heat, while the ashes, by hindering 
 
REPORT OF STATE GEOLOGIST. 255 
 
 a complete combustion, and by the heat they contain when dropped 
 through the grate, constitute another loss. By furthermore deter- 
 mining the total amount of volatile matter, we learn both the per 
 centage of coke in the fuel, and the amount of carbon (fixed com- 
 bustible) and bitumen (volatile combustible matter). Although 
 neither of these two products can be considered as simple chemical 
 compounds, it is nevertheless of the utmost practical importance to 
 know these two quantities, because of the great importance of coke 
 and gas in the arts. The yield in gas of a fuel is no doubt measured 
 by the per centage of bitumen, at least for coals from the same 
 basin — coals which therefore may be supposed to have passed 
 through nearly the same chemical history. 
 
 In taking charge of the chemical labors of the Geological Survey 
 of Iowa, I had grave doubts ii regard to the value of this proximate 
 analysis of coals. No investigation as to its accuracy, nor as to the 
 best method of conducting the work, had come to my knowledge. 
 The European chemists seem almost exclusively to rely on the 
 elementary analysis, while in the great Government surveys of this 
 country the proximate analysis seems to have been almost as exclu- 
 sively practised. But while the former may readily be turned into 
 approximate determinations of the heating effects of the fuel, the 
 latter have, to my knowledge, never been used for such purposes, nor 
 was it at all apparent that they ever could be thus made useful. 
 
 In regard to the first condition of all quantitative determinationsj 
 that of giving constant results for the same substance, but few 
 observations were accessible, and these rather increased my first 
 distrust. Thus Whitney nowhere, in his report on the coals of Iowa, 
 (Geology of Iowa, Vol. I, Pt. I), gives any data whatever in regard 
 to this most important question, although he devotes a very large 
 space to the subject. Only the final results are given ; but whether 
 the individual determinations deviated much or little from the same, 
 can not be ascertained ; or, in other words, the degree of accuracy or 
 reliability of his reported results is altogether unknown. The report 
 of Dr. James V. F. Blaney on the coals of Illinois (Geology of Illinois, 
 Vol. I, 1866, p. 258-277) insists on the great correspondence of the 
 amount of bitumen volatalized to varying circumstances, but only in 
 
25g EBPORT OF STATE GEOLOGIST. 
 
 general terms : no experimental data being brought forward. Fortu- 
 nately, this chemist gives for four samples of coal the direct result of 
 two determinations (see p. 275) ; but the differences between these 
 two determinations on the same sample are respectively : 
 
 3.04 1.50 1.32 0.07 
 
 per cent, the mean of which is 1.48, or very nearly one and a half 
 per cent. This result certainly was not calculated to incline me 
 favorably to the proximate analysis of coals. 
 
 On the other hand, the usual applications of coal demand such 
 analysis, and my reduction of the analysis of Whitney and Blaney 
 proves, by the results obtained, that the determinations must be more 
 reliable than the above figures would indicate. 
 
 It thus became necessary for me, before making any proximate 
 analysis of the many samples of Iowa coals put into my hands by the 
 State Geologist, Dr. C. A. White, to make a rather extensive and 
 thorough search into the method itself, in order to study its exact 
 value. Since I, in these determinations according to the varied 
 circumstances for the same sample ot coal, obtained values ranging 
 from 41.77 to 57.31 per cent for the amount of volatile matter, it 
 seems not only that such investigation was su^ciently called for, but 
 even that it shows the proximate analysis to be worthless : a variation 
 of 15.54, or rather 16 per cent for the same sample, seems to condemn 
 the method admitting of such results. 
 
 In the determination of magnesia, as large variations could be 
 obtained by exposing the crystalized double phosphate to varied 
 conditions ; and yet this determination, properly executed, is one of 
 the most accurate known in analysis. 
 
 It is easily seen that the following elements will modify the result 
 of the amount of volatile matter driven off from a sample of coal 
 (Contained in a covered platinum crucible : weight of coal and of 
 crucible ; degree and duration of heat ; condition of coal. I hope to 
 show that this determination, notwithstanding all these elements, 
 admits of an accuracy of one - tenth of a per cent, equal to that of 
 weighing a gramme exact to the milligramme. 
 
 The sample of coal used for this purpose was not selected, but taken 
 at random. It was labelled No. 350, and is from the bottom of 
 
REPORT OF STATE GEOLOGIST. 
 
 257 
 
 Eoberts and Fisher's Bank, which bank is five to six feet thibk, seven 
 miles west of the town of Pella, in Marion county, Iowa. From this 
 sample a very pure piece, free from any visible admixture of either 
 gypsum or pyrites, was selected. By means of 2.760 coal, in coarse 
 fragments of about 1 10 cubic centimenter and a 50 - gramme flask, 
 the specific gravity of this coal was found to be 1.328. 
 
 A. DETERMINATION OF THE VOLATILE MATTER. 
 
 Source oe Heat.- A common Bunsen burner was used (red heat), 
 and also a gas burner with six jets, surmounted by a French soufflet 
 cylindrique (white heat), care being taken to keep the gas - cock in 
 the same position by means of an arm of ten inches in length. These 
 two sources of heat we will denote respectively " B B," and " Blast." 
 
 The time was usually measured by means of a small sand - glass, 
 running exactly three and one - half minutes ; this duration we will 
 denote by t. Thus BB< means that the crucible was exposed to the 
 constant flame of the Bunsen burner during three and one -half 
 minutes. 
 
 INFLUENCE OF QUANTITY OF COAL. 
 
 1. Coal pulverized, not dried ; heat: BB/I; cooled and weighed 
 then blast, t; then weighed again.* 
 
 NO. OF 
 
 expkr't. 
 
 WEIGHT. 1 VOLATILE, 
 ™ PER CENT. 
 
 DEVIATION. 
 
 .CRUCIBLE. 
 
 d 
 n 
 e 
 
 
 
 5.360 
 1.910 
 1.147 
 1.031 
 
 48.24 
 49.58 
 49.87 
 49.85 
 
 —1.14 
 
 +0.20 
 +0.49 
 +0.47 
 
 19.2 
 
 19.2 
 
 11.6 
 
 9.4 
 
 M 
 
 
 49.38 
 
 
 
 
 
 
 
 2. Coal in small fragments : heat as in 1. 
 
 h 
 
 9 
 
 3.743 
 1.130 
 
 48.30 
 50.18 
 
 —0.94 
 +0.94 
 
 19.2 
 9.4 
 
 M 
 
 
 49.24 
 
 
 
 
 
 
 * Weight == coal taken in grammes ; crucible = weight of the same. Deviation 
 per cent from the mean given. These quantities are given in tlie same order in 
 all subsequent tables, unJess stated otherv\ise. 
 
 33 
 
258 
 
 KEPORT OF STATE GEOLOGIST. 
 
 For the same heat, the amount volatilized is the greater, the smaller 
 the mass heated ; whether the coal is in small fragments or pulver- 
 ized hardly makes any difference ; but since the bitumen passed off 
 more regularly when the coal was pulverized, while, when in frag- 
 ments, slight explosions sometimes occurred, the coal should be pul- 
 verized for the determination of the bitumen. 
 
 3. Coal, pulverized, between 1 and 2 grammes ; heat as above, 
 
 NO. OP 
 
 bxpbr't. 
 
 WEIGHT. 
 
 VOLATILE. 
 PER CENT. 
 
 DEVIATION. 
 
 CRUCIBLE. 
 
 n 
 c 
 
 
 
 1.910 
 1.147 
 1.031 
 
 49.58 
 49.87 
 49.85 
 
 —0.19 
 +0.10 
 +0.08 
 
 19.2 
 
 11.6 
 
 9.4 
 
 Mean 
 
 
 49.77 
 
 
 
 giving, as probable error of a single determination, only 0.108 per 
 cent, or only 1 milligramme for 1 gramme of coal. This is not 
 greater than that of the weighing itself, in which fractions of a 
 milligramme were usually neglected. 
 
 4. Coal, pulverized (new portion), and between 1 — 2 grammes. 
 Heat: BBi; immediately thereafter Blast <, without cooling. 
 
 NO. OF 
 
 expeb't. 
 
 WEIGHT. 
 
 VOLATILE. 
 PEE CENT. 
 
 DEVIATION. 
 
 CRUCIBLE. 
 
 a' 
 n' 
 
 1.160 
 1.040 
 
 50.86 
 
 50.58 
 
 + 0.14 
 0.14 
 
 9.4 
 11.0 
 
 Meai 
 
 [ 
 
 50.72 
 
 
 
 
 
 
 
 Another determination was made (o') ; but on account of side- 
 draft while over BB the crucible cooled several times; correspond- 
 ingly the result deviated much, being only 49.10. 
 
 From 3 and 4 we conclude, that if the substance taken is from 1 
 to 2 grammes, the result will be constant for the same mode of 
 heating. .^ 
 
» 
 
 REPORT OF STATE GEOLOGIST. 
 
 259 
 
 INFLUENCE OF DRYING THE COAL BEFORE IGNITION. 
 
 5. Coal, fragments ; heat, BB<; not cooled; Blasts 
 
 NO. OF 
 
 EXPEli'T. ^=^™'^- 
 
 VOLATILE. 
 PER CENT. 
 
 DBVIATION. 
 
 t 
 
 u 
 
 1.361 
 1.060 
 1.030 
 
 48.49 
 47.26 
 47.43 
 
 +0.76 
 -0.47 
 —0.80 
 
 Mean 
 
 
 47.73 
 
 
 with the probable error of one single determination 0.45. 
 
 Comparing this with 4 (same heating) it appears that about 3 per 
 cent less volatilized by previous drying, and also that the accuracy 
 of one determination is four times less than when the coal is ignited 
 without previous drying. In the arts the coal is not artificially dried 
 before coking. For all of these reasons the amount of volatile 
 matter is best determined on undried coal. 
 
 6. In general, I found, as means, 
 
 4 dried coals gave 47.97 per cent volatile, 
 10 undried coals gave 49.87 per cent volatile, 
 confirming the above. 
 
 INFLUENCE OF COOLING AFTER THE IGNITION OVER THE BUNSEN 
 BURNER, AND BEFORE THE IGNITION OVER THE BLAST - FLAME. 
 
 7. Coal, pulverized, not dried; heai; BBii; then Blasts, without 
 cooling. ' 
 
 NO. OP 
 
 exper't. 
 
 WEIGHT. 
 
 VOIATTLB 
 PEE, CENT. 
 
 DEVIATION. 
 
 X 
 
 y 
 
 1.814 
 1.156 
 
 49.01 
 
 49.05 
 
 —0.02 
 
 + 0.02 
 
 Mean 
 
 
 49.03 
 
 
 which compared with the corresponding case 3, giving the mean 
 49.77 and maximum deviation 0.19, shows that by the intermediate 
 cooling about | per cent more is volatilized. This probably is due 
 to the fact that the crucible upon cooling is filled with atmospheric 
 air, which, upon renewed ignition, must burn a corresponding amount 
 of the coal. 
 
260 
 
 REPORT OF STATE GEOLOGIST. 
 
 INFLUENCE OF EBPEATBD HEATINS, THE CRUCIBLE BEING AFTER EACH 
 IGNITION COOLED AND WEIGHED, 
 
 8. Coal=r=^ 1.628 in crucible 19.2 was dried, then ignited, 
 {BBt) and lost 41.77 per cent. Being ignited again in the same 
 way, it lost 2.76 per cent, or, in all, 44.53. Being successively 
 ignited 7 times, BB, each time for 6 minutes, the total loss was 
 52.39, or, on the average for each of these 6 - minute BB ignitions, 
 1.12] two of the determinations nearest this average were 1.06 per 
 cent). 
 
 Hereafter the same was 5 times for 3J minutes exposed to the 
 blast; the volatile passed off amounted to 57.31, giving for each of 
 these last ignitions the average loss of 0.98 per cent. 
 
 It now had been ignited 14 times, each time having been cooled 
 and weighed ; and we have 14 ignitions, 57.31 volatile: 1st ignition 
 41.77 volatile ; hence average for each of the 13 ignitions 1.195 
 or 1.2 per cent. 
 
 This series of experiments shows that it is impossible to heat coal 
 until no further loss is sustained ; for it is apparent that each heating 
 (after complete cooling) produces, on the average, more than the 
 additional volatization of 1. On 1 gramme coal taken, 1 per cent 
 carbon burnt requires about 30 milligrammes or 20 cubic centimeters 
 of oxygen. We may therefore consider these successes almost equal 
 losses due to a real combustion. 
 
 INFLUENCE OF PKOTEACTBD HEATING. 
 
 9. Coal, pulverized, not dried; heat, always first BB i, and then 
 immediately, without cooling, transferred to blast - lamp. 
 
 NO. 
 
 WEIGHT. 
 
 BLAST. 
 
 VOLATILE. 
 
 DIFFEBBNCB 
 
 DIPFBKENCE 
 PER MINUTE. 
 
 a'+n' 
 
 (mean) 
 
 3 min. 
 
 50.72 
 
 0.57 
 
 0.19 
 
 c' 
 
 
 6 " 
 
 51.29 
 
 1.04 
 
 0.35 
 
 b' 
 
 
 9 " 
 
 62.33 
 
 1.95 
 
 0.65 
 
 d' 
 
 
 12 " 
 
 54.28 
 
 2.93 
 
 0.16 
 
 k' 
 
 
 30 " 
 
 57.21 
 
 
 
 By comparing each with the first mean, we obtain for each minute- 
 blast after the first 3, respectively, 
 
 0.24 0.39 0.27 0.20 
 
 showing less difference than the above. 
 
REPORT OF STATE GEOLOGIST. 261 
 
 The volatilization, after the three first minutes - blast, is therefore 
 increasing i to f per cent for six minutes, and then very slowly 
 decreasing to about i per cent for half an hour. At this rate the 
 loss is 12 per hour. 
 
 It is apparent that this loss is less than -when cooled in the inter- 
 vals, but it proves that a slight current of air must get at the coal in 
 the covered crucible. 
 
 At any rate it is demonstrated, that the rule which is sometimes 
 given, to heat until no further loss is sustained, demands an impossi- 
 bility. 
 
 INFLUENCE OP THE DEQEEE OP HEAT. 
 
 10. CoaZ, pulverized, not dried; heatfBBt; cooled and weighed; 
 then Blast i ; cooled and weighed again. 
 
 APTBB BB. AFTBK BLAST. 
 
 n 1.910 48.08 +0.42 
 e 1.147 47.69 +0.03 
 1.031 47.23 —0.43 
 
 49.58 —0.18 
 49.87 +0.11 
 49.85 +0.09 
 
 Mean 47.66 49.76 
 
 Probable error.. 0.284 0.108 
 
 showing that the higher temperature gives the most accurate results. 
 
 RESULT. 
 
 From this investigation we conclude : 
 
 The total volatile matter of coal is determined with accuracy (1 mgr. 
 on 1 gr. coal) by taking 1 to 2 grammes of undried pulverized coal, 
 heating it for SJ minutes over a Bunsen burner (bright red heat) and 
 then immediately, without cooling, for the same length of time over a 
 blast gas -lamp {white heat.) 
 
 B. DETERMINATION OF THE MOISTURE. 
 
 A flat - bottomed iron pan, of 20 centimeters in diameter, was filled 
 evenly to the depth of IJ centimeters, with sand, and the latter was 
 covered with a copper plate, on which the watch - glass containing 
 the coal was placed. A thermometer (scale to 370°C.) was, by means 
 of a rubber stopper, inserted in an iron arm of the tripod supporting 
 the iron pan, and held with its bulb about half a centimeter above 
 
262 
 
 REPORT OP STATE GEOLOGIST. 
 
 the copper plate. By means of a Bunsen burner it was found very 
 easy to keep the thermometer perfectly constant at 115°C. This 
 apparatus I consider a good substitute for Fresenius' iron plate. 
 
 The coal to be dried was finely pulverized, direct experiments 
 having convinced me that the application of fragments was not only 
 very much slower, but also erroneous, on account of the peculiar 
 property of bituminous coal treated of below. 
 
 In order to show the accuracy of this method, I transcribe the fol- 
 lowing examples from my journals: 
 
 
 
 
 MOISTnEE. 
 
 
 No. of 
 coal. 
 
 Weight of 
 portion. 
 
 Time. 
 
 
 
 
 Per cent. 
 
 Deviation from 
 Mean. 
 
 Mean. 
 
 390 e 
 
 0.961 
 
 1 hour. 
 
 4.888 
 
 —0.004 
 
 4;892 
 
 390 f 
 
 0.919 
 
 1 hour. 
 
 4.896 
 
 +0.004 
 
 4,892 
 
 390 e 
 
 0.961 
 
 2J hours. 
 
 4.16 
 
 +0.01 
 
 4.15 
 
 390 f 
 
 0.919 
 
 2^ hours. 
 
 4.14 
 
 —0.01 
 
 4.15 
 
 339 e 
 
 1.452 
 
 1 hour. 
 
 8.26 
 
 +0.07 
 
 8.19 
 
 339 f 
 
 0.975 
 
 1 hour. 
 
 8.12 
 
 —0.07 
 
 8.19 
 
 339 e 
 
 1.452 
 
 3 hours. 
 
 7.16 
 
 +0.17 
 
 8.19 
 
 339 f 
 
 0.9T5 
 
 3 hours. 
 
 6.83 
 
 —0.16 
 
 8.19 
 
 338 e 
 
 1.415 
 
 1 hour. 
 
 3.852 
 
 —0.029 
 
 3.881 
 
 338 f 
 
 0.805 
 
 1 hour. 
 
 3.911 
 
 +0.030 
 
 3,881 
 
 338 e 
 
 1.415 
 
 2J hours. 
 
 3.287 
 
 +0.123 
 
 3,164 
 
 338 f 
 
 0.805 
 
 2J hours. 
 
 3.042 
 
 0.122 
 
 3,164 
 
 338 e 
 
 1.415 
 
 bi hours. 
 
 2.722 
 
 +0.088 
 
 2,634 
 
 338 f 
 
 0.805 
 
 5i hours. 
 
 2.546 
 
 — 0.08S 
 
 2,634 
 
 These results — a few taken from among a great number of deter- 
 minations — show that the loss (called moisture) decreases regularly 
 after the first hour of drying, that is to say, while the coal loses in 
 weight during the first hour, it steadily gains in weight thereafter. 
 It appears furthermore, that the accuracy of a determination, ex- 
 pressed in the smallness of the deviations from the mean, is greatest 
 at the end of the first hour of drying, least after about three hours 
 of drying, and thereafter increases again as expressed in the dimi- 
 nution of the deviations after five and one - half hours drying in coal 
 No. 338. 
 
 On account of these peculiar properties of our bituminous coal, I 
 put down as moisture the loss in weight of the finely -pulverized coal 
 after one hour's drying at a temperature between 105° and 110°C. 
 
REPORT OP STATE GEOLOGIST. 263 
 
 C. ON THE SLOW OXIDATION OF COAL. 
 
 This increase in weight after the first hour's drying I have found 
 in all Iowa coal investigated as yet. I have also found it to occur in 
 a sample of coal (steinkohle) from Beuthen, Silesia, which showed a 
 loss of 3.62 per cent at the close of one hour, and in four further 
 hours' drying gained again 0.42 per cent ; also in cannel coal from 
 Wigan, England, which gained 0.42 per cent. It was not noticed in 
 brown coal from Bilin, Bohemia, nor in brown coal from Arbesan, 
 Bohemia, nor in bituminous wood from Salzhausen, Germany, nor in 
 peat from Ireland, nor in anthracite from Pennsylvania. I am there- 
 fore inclined to believe this to be a property peculiar to pit - coal 
 (steinkohle). 
 
 On page 401 of Vol. I. P. I. of the Iowa Geology, Prof. Whitney 
 remarks : " A remarkable fact, in connection with the determination 
 of the water present in the specimens of coal has been noticed. In 
 numerous instances, after the sample, in the form of a coarse powder, 
 had been dried for several hours in the air bath, at a temperature a 
 little above that of boiling water, during which time it had gradually 
 lost weight until all the water seemed to have been expelled, on con- 
 tinuing the operation for some time longer a slight increase of weight 
 would become perceptible, and the coal would continue to grow heavier 
 until a gain of several tenths of a per cent of the original weight had 
 been made. This appears to be owing to the slow oxidation of the 
 sulphur which all these coals contain in a finely divided state, dis- 
 seminated in invisible particles through the mass, and, perhaps, 
 partly in combination with iron." 
 
 It is evident that Prof. Whitney failed to discover this property 
 as a general one, because he had the coal in coarse fragments. The 
 want of correspondence in the results of determinations of moisture 
 in the same sample, dried at the same time, but of different weights, 
 made me apply the coal in the form of powder. Thereby the turning 
 point was reduced from " several hours " to less than one hour ; the 
 '"numerous instances" extended to all samples investigated; the 
 "slight increase of several tenths of one per cent" became often 
 two and even four per cent ! Instead of numerous exceptions we 
 now discovered a general law. 
 
264 REPORT OF STATE GEOLOGIST. 
 
 We have failed, as yet, to notice any " sulphur " disseminated 
 through the Iowa coal ; what popularly is called sulphur is pyrites. 
 Prof. Whitney has given no proof of the existence of real " sulphur " 
 in the coal. It is therefore unsatisfactory to ascribe this property 
 of the bituminous coals to such " sulphur." 
 
 Pyrites might well be the cause of this phenomenon ; the red 
 ashes obtained in many cases (in Van Buren County, Iowa, invaria- 
 bly from the upper part of the coal -bank), may well be ascribed to 
 pyrites disseminated through the coal in invisible particles. 2 
 FeSj will give FejOa, +4SO3, by exactly doubling their weight. 
 
 In order to decide the question, I select the following results from 
 my analyses : 
 
 INFLUENCE OP TIME OF DRYING. 
 
 Top - coal. Number of samples. 
 
 4 
 
 3 
 
 2 
 
 Time of drying. 
 
 2 
 
 3 
 
 4-5 hours. 
 
 Mean gain per cent, 
 
 0.45 
 
 0.71 
 
 0.96 
 
 Bottom, coal. No. of samples. 
 
 3 
 
 5 
 
 2 
 
 Time of drying, 
 
 2 
 
 3 
 
 4 hours. 
 
 Gain, per cent. 
 
 0.49 
 
 0.50 
 
 0.96 
 
 Mean of above. No. of samples, 
 
 7 
 
 8 
 
 4 
 
 Time of drying. 
 
 2 
 
 3 
 
 4-5 hours. 
 
 Gain, per cent, 
 
 0.46 
 
 0.68 
 
 0.96 
 
 Gain, per hour. 
 
 0.23 
 
 0.21 
 
 0.24 
 
 or, on the whole, for nineteen samples of coal, very nearly propor- 
 tional to the time, this being not more than four hours. It also 
 appears, that no essential difference is apparent in regard to the 
 position of the sample in the coal - bank. 
 
REPORT OP STATE GEOLOGIST. 
 
 265 
 
 By this means we may compare the following determinations, 
 referring to 2, 3, or 4 hours drying. We find : 
 
 HOURS. 
 
 INCREASE 
 TOTAL. 
 
 PER CT. 
 PER HR. 
 
 DIFFEBBNCB 
 
 COLOR OF ASHES. 
 
 I Top. . 
 
 ( Bottom . 
 ( Bottom . 
 
 I Top. ... 
 j Top ... . 
 
 ( Bottom . 
 Top 
 
 ( Bottom. . 
 JTop 
 
 ( Bottom . 
 Middle.. 
 
 (Top 
 
 390 
 
 384 
 395 
 
 375 
 346 
 
 371 
 336 
 
 334 
 333 
 
 340 
 357 
 
 370 
 
 2 
 
 4 
 
 4 
 3 
 
 3 
 3 
 
 3 
 3 
 
 3 
 3 
 
 0.75 
 
 0.35 
 0.80 
 
 0.64 
 0.68 
 
 0.45 
 0.76 
 
 0.58 
 1.17 
 
 0.91 
 0.55 
 
 0.46 
 
 0.38 I 
 
 0.16 
 0.20 
 
 0.16 
 0.23 
 
 0.15 
 0.25 
 
 0.19 
 0.39 
 
 0.30 
 0.18 
 
 0.15 
 
 0.22 
 04 
 0.08 
 0.08 
 0.09 
 003 
 
 Pale brown. 
 
 White 
 
 Red and white. 
 
 White 
 
 Reddish brown . 
 
 White . 
 Gray.. 
 
 Gray. 
 Pink. 
 
 Light gray. 
 White 
 
 Reddish 
 
 Except in the coal from the last mine, we notice that the more 
 ferruginous ash does correspond to a slightly greater increase in 
 weight ; but we notice also that this difference is but very small as 
 compared to the total amount of increase, being only one - fifth to 
 one - third of the whole. Arranging these coals in the order of this 
 hourly increase, we find the color of the ashes not at all forming a 
 regular series from white to red, as it ought to be if this increase 
 was mainly depending upon the oxidation of the pyrites. Besides, 
 the mean of the 4 white - ash coals is 0.16 per cent hourly increase, 
 while the m.ean of the 4 coals showing the greatest increase is only 
 0.33 per cent, or double the former. 
 
 Coal, 333 Increase, 0.39 per cent. 
 
 
 390 
 
 
 0.38 
 
 
 
 340 
 
 
 0.30 
 
 
 
 386 
 
 
 0.25 
 
 
 
 346 
 
 
 0.23 
 
 
 
 395 
 
 
 0.20 
 
 
 
 334 
 
 
 0.19 
 
 
 
 357 
 
 
 0.18 
 
 
 
 375 
 
 
 0.16 
 
 
 
 384 
 
 
 0.16 
 
 
 
 371 
 
 
 0.15 
 
 
 
 370 
 
 
 0.15 
 
 
 ish 
 
 : pink. 
 
 (( 
 
 pale brown. 
 
 (( 
 
 light gray. 
 
 
 gray. 
 
 a 
 
 reddish brown. 
 
 a 
 
 red and white. 
 
 ii 
 
 gray. 
 
 a 
 
 white. 
 
 ii 
 
 white. 
 
 a 
 
 white. 
 
 a 
 
 white. 
 
 a 
 
 reddish. 
 
 34 
 
266 EEPORT OF STATE GEOLOGIST. 
 
 The greater increase of the pyritiferous coals is accounted for by 
 the oxidation of the pyrites they contain ; the comparatively great 
 increase of coals giving a pure white ash seems to force the con- 
 clusion upon us, that the litumen of the coal itself oxidizes, and that 
 to this oxidation the main increase of all these bituminous coals must 
 be ascribed. Remembering now our result regarding the deportment 
 of bituminous coal from Silesia, anthracite from Pennsylvania, brown 
 coal from Bohemia, (all of which gave ashes very nearly of same 
 shade, and all of which had been in my air - heated laboratory for 
 two years), it seems not unlikely that this is another characteristic 
 chemical difference between bituminous coals and other fossil coals. 
 
 In conclusion I will only give two additional determinations, show- 
 ing a very considerable increase in weight, and also that the f recess 
 of oxidation is completed in about six hours for two - thirds grammes 
 of coal. For No. 329, containing 8.30 per cent of gray ashes, 
 gained, in 5| hours, 2.05 per cent of its original weight. Coal No. 
 348, with 6.00 per cent red ashes, weighed 0.693. 
 
 After 
 
 D. DETERMINATION OF THE ASHES. 
 
 The best way to determine the ashes in coal I found to be the 
 coking of the finely pulverized coal in a small platinum dish (weigh- 
 ing about 8 grammes) with subsequent incineration of this coke in 
 the same vessel. The incineration takes place with great ease and 
 rapidity, and the results are perfectly satisfactory. Thus 3.022 
 grammes of coal No. 333 gave 2.35 per cent, and 5.263 grammes of 
 the same coal gave 2.58 per cent, deviating from the mean 2.46 
 by +0.11. 
 
 In regard to the ashes of our Iowa coals, I have found that they 
 are very much more uniform in their distribution throughout the 
 coal-fields than usually thought possible. In Van Buren county, I 
 find the " bottom " coal giving a white or light colored ash, the " top" 
 coal of the same bank a red colored ash ; a fact, which I intend to 
 
 
 
 Change: 
 Weight. Per cent. 
 
 Total loss 
 Per cent. 
 
 f hour. 
 
 0.630 
 
 loss 0.063 9.091 
 
 9.091 
 
 2 hours. 
 
 0.625 
 
 " 0.005—0.722 
 
 9.813 
 
 5J hours, 
 8|- hours. 
 
 0.656 
 0.656 
 
 gain 0.031—4,474 
 " 0.000 
 
 5,339 
 5.330 
 
REPORT OP STATE GEOLOGIST. 267 
 
 make use of in a subsequent paper on the origin of our coal. I also 
 find the amount of ashes to increase quite evenly (in this county), 
 toward the margin of the coal - field, from about 2 to 7 per 100 
 combustible. 
 
 E. DETERMINATION OF SPECIFIC GRAVITY. 
 
 Coarse fragments, freed by means of a sieve, from all small 
 particles, and averaging 1-10 cubic centimeters in volume, were 
 introduced into a fifty -gramme flask, provided with thermometer 
 stopper. The constants for this flask, for temperatures varying from 
 50° to 80° F. had been carefully determined. 
 
 The given specific gravity corresponds to the coal perfectly 
 soaked, so that all its pores were filled with water. That required, 
 on the average, twelve hours, permitting two determinations per day, 
 one in the morning, another in the evening. 
 
 That this is not at all trifling, may be seeii from the following 
 example. 2.760 grammes coal (No. 350) gave the specific gravity 
 1.309 at 64° F., immediately after filling the flask with water ; after 
 about twelve hours soaking, the specific gravity had increased to 
 ( (I 1,328, for the same temperature. According to this latter determina- 
 tion, a cubic foot of this coal would weigh 82.76 lbs.; according 
 to the former, only 81.58, or 1.18 lbs. less. This shows a consider- 
 able degree of porosity ot the coal ; and indicates the absurdity of 
 giving the weight in pounds of a cubic foot of coal with four 
 decimals, although no statement in regard to temperature or time of 
 weighing is made. Such accuracy we meet with in some of the 
 official reports. 
 
 F. CALCULATION OF RESULTS. 
 
 Referring to my paper in No. 22 of the American Journal of 
 Mining, it may be sufficient here to state, that beside the per centage 
 composition of the coal, it is proper to reduce the composition to the 
 combustible = 100, in order to obtain a proper comparative estimate 
 of the character of the fuel itself (in regard to the proportion of 
 bitumen and carbon) and of the amount and quality of the impurities 
 ashes and moisture). It has also been shown in the paper referred 
 to, that for considerable areas of the coal - field, the sum of the con- 
 stituents on the scale of combustible = 100 is the proper caloric 
 
268 KEPORT OF STATE GEOLOGIST. 
 
 equivalent, and that the per centage of the combustible in the fuel 
 gives a proper estimate of its value. 
 
 According to this method a considerable number of analyses of 
 Iowa coals have already been made. It is believed that the results 
 will be strictly comparable for the entire coal-field of Iowa, and that 
 the conclusions, both practical and theoretical, will deserve some 
 confidence. 
 
THE MINERALOGY OF IOWA. 
 
 CHAPTER IV. 
 
 Elements : 
 
 Oxides : 
 
 Sulphides : 
 
 Carbonates : 
 
 The following mineral species have come under my personal 
 observation : 
 
 1 Coal. 
 
 2 Sulphur (cryst). 
 
 3 Quartz. 
 
 4 Chalcedony. 
 
 5 Hematite. 
 
 6 Limonite (and Ochre). 
 
 8 Wad. 
 
 9 Galena. 
 
 10 Blende. 
 
 11 Pyrites. 
 
 12 Calcite in very many varieties and 
 forms. 
 
 13 Smithsonite. 
 
 14 Dolomite. 
 15. Aragonite. 
 16 Cerusite. 
 
 Sulphates, anhydrous : 17 Celestine. 
 
 18 Barytes, hydrated. 
 
 19 Gypsum. 
 
 20 Epsomite. 
 
 21 Alum. 
 
 Silicates : 22 Kaolin (and fire - clay). 
 
 By reference to the Report on the Geological Survey of Wiscon- 
 sin, Volume I, 1862, where, in chapter V, Prof. Whitney gives, the 
 mineralogy of the lead region, we may consider the italicised species 
 
270 REPORT OP STATE GEOLOGIST. 
 
 Sulphur, Aragonits, Carusite, Celestine, the first three having been 
 (found in well crystalized specimens) as not before identified in Iowa. 
 It will be most convenient to consider the minerals of the princi- 
 pal localities separately. 
 
 1. THE DUBUQUE LEA.D REGION. 
 
 1. Galena. — Lead sulphide, "PbS ; the ^^ mineral" of the miners. 
 This ore occurs in two sets of lodes, nearly at right angles to each 
 other. The principal lodes run east and west, the secondary lodes 
 run north and south ; some have an intermediate course, and are 
 called quartering lodes. The galena from these lodes may be readily 
 distinguished. 
 
 In the east and west lodes the ore is usually imbedded in the clay, 
 which more or less fills the cavity produced by the disintegration of 
 the rock (magnesian limestone). The ore itself is darker, shows fre- 
 quently good cubes (" dice mineral " of the miner), has a good, reg- 
 ular, cubical cleavage throughout. The ore is sometimes of very con- 
 siderable dimensions. 
 
 In the north and south lodes the ore occurs usually in sheets, 
 rarely more than three inches thick, tightly imbedded in the rock. 
 It is of a lighter color, never shows any well - defined cubes, nor any 
 distinct, regular cleavage. It is more compact, so as to give a some- 
 what ringing sound when struck ; hence it is also called " steel min- 
 eral." It is said to yield more lead, to be more easily reduced, and 
 to contain more silver than the east and west mineral. On the south 
 fork of the Little Makoqueta river much of the north and south 
 mineral is mined. 
 
 In the quartering lodes the characters of the ore are also inter- 
 mediate. 
 
 Crystaline forms observed are the cube and the octohedron ; the 
 latter always in combination with the former. Very fine cabinet 
 specimens may be seen in the cabinet of amateurs and miners at 
 Dubuque. Some specimens have c«bes only on one side, while the 
 other is studded with octohedra, retaining but small cubical faces. 
 The largest cube I have observed is in the cabinet of Mr. James 
 Beach, Dubuque; it measures 4iX4JX6f inches, has the corners 
 unequally replaced by octohedral faces, and weighs 16 J pounds. 
 
REPORT OF STATE GEOLOGIST. 271 
 
 2. -B?ew(?e. — Zinc -sulphide, Zn S; the "Black Jack" of the 
 miners. It is not as abundant as the former ; more common on the 
 east side of the Mississippi. Only the ferruginous, black variety has 
 been observed ; no finely -developed crystals, although the masses 
 exhibit the peculiar dodecahedral cleavage very well. 
 
 The disintegration of the blende takes place according to the 
 directions of cleavage. Several specimens, partly disintegrated to 
 carbonate, showed this feature very finely. In some of these speci- 
 mens of carbonate, the dodecahedral rhombohedron of 120 degrees is 
 easily recognized. 
 
 3. Pyrites. — Iron disulphide, Fe S^ ; "niundic" of the miners. 
 Also this mineral is much more abundant in the eastern portion of 
 the lead region of the Upper Mississippi than in the Iowa district of 
 this region. I have observed it in most beautiful and regular octa- 
 hedra of about one - tenth of an inch ; also dodecahedra have been 
 observed by me. I do not remember to have seen a single cube of 
 pyrites from this region. This form is dominating in the geodes 
 in southern Iowa, and the pyritohedron I have seen in pyrites from 
 a coal - mine twelve miles south of Davenport. 
 
 3. Cerusite. — Lead carbonate, PbOjO. The galena often has a 
 white coating of amorphaus lead carbonate. In the quartering lode 
 of Messrs. Burton, Hill & Co., I found some very good, though small, 
 crystals of cerusite, right on the galena, in fissures of the mineral. 
 
 5. Aragonite. — Prismatic, calcium - carbonate, CaOjO. Mr. 
 Woodman, of Dubuque, has obtained some very fine specimens, 
 beautiful groups of small crystals, from a cave seven miles south 
 of Dubuque, and one mile west of the river. I discovered some, 
 almost microscopic crystal, right on the galena, in fissures of the 
 ore, at the above - mentioned mine of Burton, Hill & Co, five miles 
 north of Dubuque. 
 
 6. Calcite. — Rhombohedral calcium-carbonate, CaOjC, the " Tiff" 
 of the miners. It is very common in the diggings. The scaleno- 
 hedron R8 is at times found very finely developed, in combination 
 with the vertical hexagonal prism and the fundamental rhombohedron ; 
 the crystals often projecting three and more inches. 
 
272 REPORT OF STATE GEOLOGIST. 
 
 In the pools of the caves large cakes, consisting of an agglomera 
 tion of acute rhombohedra with parallel axes, are formed by slow 
 crystalization. The surfaces of these rhombohedra are never 
 smooth, being studded with smaller rhombohedra of the same form 
 and in parallel position. 
 
 Rock - milk, pure white, associated with Wad, has been found in 
 specimens from the Peacock mine. 
 
 Stalactites and Stalagmites of considerable size are still seen in 
 Dubuque ; Satin, Velvet Spar, forming beautiful arborescent forms, 
 may be seen in the local cabinets. 
 
 The most remarkable calcite crystal I have observed if a scaleno- 
 hedron from the Peacock mine. It is about three inches by two, and 
 at a distance of f inches below its surface, a perfectly parallel 
 scalenohedron is finely marked by very small crystals of pyrites. 
 
 7. Smiihsonite. — Zinc -carbonate, ZnOjC, The common amor- 
 phous variety, resulting from the blende, is quite frequent ; the 
 miners call it " dry bone." From the iron of the black-jack it 
 is always yellowish or reddish. 
 
 Very finely crystalized Smithsonite is rare, but has been observed ; 
 some crystals were fully j\ inch in diameter. 
 
 8. Barytes. — Barium - sulphate, BaO^S or heavy spar. Good 
 tabular crystals of bluish tint have been observed, from Peacock 
 mine. 
 
 Gypsum. — Hydrated calcium - sulphate, CaO^S + 2H20. It is 
 not common in the lead -mines; usually in small, scaly coatings, 
 and tabular crystals ; also bunches of fibrous gypsum (Peacock 
 mine.) 
 
 10. Sulphur, S. — Beautiful crystals, about ^ inch in diameter, 
 fine yellow color, on galena, probably from the St. John's diggings, 
 four to five miles north of Dubuque. Beside the terminal plane 
 (OP), and the fundamental pyramid (P) ; also ^P distinctly 
 observed. 
 
 While at the Hickock mine (July, 1867) I discovered a consider- 
 able amount of solid sulphur and dry bone, on blende. The pieces 
 were often as large as a small pea, quite compact, exhibiting some 
 lustre, but no distinct crystalization. The shaft, wherein these 
 specimens were obtained, was only about twenty feet deep. 
 
REPORT OF STATE GEOLOGIST. 273 
 
 ^^- — ^'^^> impure manganese-oxide. Associated with rock - milk 
 at the base of stalactites from the Peacock mine. Also found at the 
 mine of Burton, Hill & Co. 
 
 12.— Zimonite, hydrated ferric-oxide, FeA+SHjO. Impure, not 
 fine specimens, quite common. Yellow ochre rather abundant. 
 Goethit, in fine scales, doubtful. 
 
 The order of succession of these minerals, as resulting from a 
 careful and minute study of all the specimens of the survey and a 
 great many most excellent specimens in the cabinets of gentlemen at 
 Dubuque, is for the Dubuque lead region essentially. 
 
 Rock: Galena limestone („, dolomite). 
 
 1. Pyrites. 
 
 2. Galena. 
 
 4. Limonite. 
 
 5. Oerusite. 
 
 3. Blende. 
 
 6. SmitJisonite, 
 
 7. Sulphur. ■ Sulphur. 
 
 -^ 8. Calcite. 
 
 ■ 9. Gypsum. 
 
 10. Barytes. 
 
 Several of these occur more than once in the series ; in the above 
 is given the order of ih&iv first occurrence. 
 
 On the east side of the river the order of the sulphides is appa- 
 rently the reverse. In a great number of very fine specimens from 
 Galena, Illinois, and from Wisconsin (some of which I studied in the 
 cabinet of Mr. Woodman, of Dubuque, the order of the sulphides is 
 blende — galena — pyrites; while for the Iowa lead -region it seems 
 to be, pyrites — galena — blende. It must be stated, though, that 
 the specimens from Illinois were rather finer than any from Iowa I 
 have been permitted to study. 
 
 On one fine specimen, observed on board a Mississippi' steamboat, 
 I noticed calcite partly between galena and pyrites. Part of the 
 galena was coated with calcite, and over the remaining galena sur- 
 face, and part of the calcite, pyrites had been deposited in octahedra 
 
 and dodecahedra. 
 35 
 
274 KEPORT OF STATE GEOLOGIST. 
 
 2. THE GEODE REGION. 
 
 For the location and extent of the region where the "■ geode led" 
 occurs in Southern Iowa, we refer to the published Geology of Iowa. 
 
 A great number of geodes, particularly from Bentonsport, Van 
 Buren county, have been closely studied. These geodes varied from 
 one inch to one foot in diameter; many were quite globular, and 
 many are flattened. The wall varies very much in thickness, and 
 this thickness is not at all proportionate to the dimensions of the 
 geode. The outer surface is always uneven, rough. At times it 
 contains a number of good, more or less corroded, cubes of pyrites. 
 No other minerals have been noticed on the outside of the geodes. 
 
 The following minerals have been observed on the inside of the 
 geodes : 
 
 1. Chalcedony forms always the outer crust, often more than an 
 inch thick. Some geodes contain no other mineral ; then the chalced- 
 dony is of a peculiar mammellar structure, and often shows, in its 
 fracture, agate - like bands. Colors are usually not showy ; pale 
 
 ' gJ^^yj bluish - gray, and yellowish - gray predominate ; greenish and 
 reddish tints have been observed. Some of these chalcedonic 
 specimens are very fine. 
 
 2. Quartz, silicon di-oxide, SiOj. — It occurs always implanted 
 on the chalcedony. Nearest the latter the quartz is only crystaline, 
 but farther toward the interior of the geode the structure of the quartz 
 becomes more regular, and the inner free surface is always formed 
 of fine crystals. Very often these radiate from a common center, 
 forming bunches in various parts of the geode ; the center is always 
 a tube. 
 
 The most common crystaline form is the hexagonal pyramid, 
 implanted on the inner surface of the geode ; but the rhombohedran 
 of 94° is also quite common, often very large (half an inch 
 along the edges !) In a lot of geodes from Hamilton, Illinois, 
 collected bj Mr. Safi'ord, a regular gradation from this rhombohedral 
 quartz to the peculiarly rounded chalcedony could be traced , pure 
 quartz rhombohedra — the same very thinly coated with chalcedony — 
 this coating thicker, so the edges appear quite rounded ; finally .the 
 rounded forms of chalcedony. 
 
REPORT OP STATE GEOLOaiST. 275 
 
 In many geodes the hexagonal prism is very finely developed, both 
 in combination with the rhombohedron, and with the hexagonal 
 pyramid ; in many this pyramid had only the alternate (rhombohedral) 
 faces well developed, the others being often rudimentary. This, 
 together with the occurrence of the rhombohedron alone, again is in 
 favor of considering the rhombohedron as the fundamental form. 
 
 Some geodes contain a great number of loose quartz crystals, up 
 to half an inch in length. The fine, transparent crystals of this 
 kind belong to the most evenly - developed, and most beautiful 
 rock crystals I have seen. These loose crystals have always a 
 hexagonal prism of some length ; and in some geodes this is com- 
 bined with the rhombohedron alone, in others with the hexagonal 
 pyramid, usually with the two rhombohedral halves unequally 
 developed, but at times the hexagonal pyramid is also perfect. 
 
 In a few geodes, thick short quartz crystals (prism and pyramid) 
 were found densely studded with minute pyramidal quartz crystals, 
 so as to form rounded bunches of exquisite beauty. 
 
 The colors of quartz in these geodes is various — from clear 
 transparent to white, yellowish, dark - yellow, yellowish - brown, red ; 
 some few have a fine rose color. 
 
 3. Oalcite occurs quite frequently, often filling the whole cavity 
 of the geode, usually resting on quartz. Sometimes the crystals are 
 very large and beautiful, but the surfaces have a somewhat silky 
 luster, due to the partial disintegration in the direction of the 
 cleavages. The principal forms observed are : 
 
 1. The fundamental rhombohedron of 105° 5'. 
 
 2. The first obtuse rhombohedron or fR of 135°. In one geode 
 from Keokuk several of these occur, one having a diameter of three 
 inches, and a hight of one inch. 
 
 8. The veritical hexagonal prism; the longest observed is 3J 
 inches (IJ inch diameter) ; the thickest, 2J inches in diameter (and 
 3 inches- long). 
 
 4. The common scalenohedron, R3 of 104° 38' and 144° 24' in 
 the terminal edges ; only subordinate in combinations with No. 3 
 and No. 6. 
 
 5. The scalenohedron | R^, having the terminal edges of 164° 
 
276 EEPORT OF STATE GIOLOGIST. 
 
 and 130J°. This with the prism of 2| inches diameter and 3 inches 
 height. 
 
 6. The scalenohedron JR5, having the terminal edges of 146° 
 and 128°; in another geode, in combination with the hexagonal 
 prism of 85^ inches length and IJ inches diameter. 
 
 4. Dolomite. — (Mg,Ca) O3C. Very fine varieties of pearl spar 
 have been observed in several geodes. Some portions had been con- 
 verted into limonite, without losing the characteristic form. The 
 largest crystals of this kind I observed in a geode from Hamilton, 
 Illinois ; the edges being nearly half an inch long. 
 
 5. Pyrites occur quite frequently in these geodes — almost always 
 in the form of small, very regular cubes. Only very few had their 
 corners finely truncated (octahedral). The largest cubes were found 
 on the outside of a few geodes. 
 
 In one geode a mass of pyrites (one inch by one and one - half 
 inches) represents on its surface a peculiar foliaceous structure. The 
 angless do not correspond with selenite, nor do they quite coincide 
 with rhombohedral calcite ; yet the mass seems to be a pseudo- 
 morph. 
 
 The pyrites is but rarely quite unaltered in these geodes ; it occurs 
 frequently converted into 
 
 6. Hematite, FojOj, and also into 
 
 7. Limonite, retaining the form perfectly and often including a 
 small nucleus of unaltered pyrites in the middle. 
 
 8. Ochre, particularly the yellow, fills some cavities almost en- 
 tirely. 
 
 9. Blende has been observed, in one geode as much as half an 
 inch cube. Smithsonite has not been noticed by me. 
 
 10. Kaolin or porcelain clay is fou^id as a fine, perfectly white 
 powder in many geodes. 
 
 11. Incrustations of various colors and compositions are fre- 
 quently coating quartz, calcite and others. Calcareous incrustations 
 are the most common, and as far as observed are usually local, speak- 
 ing for infiltration. 
 
 The general order of succession of these minerals, in the geodes 
 observed by me, is 
 1 . Chalcedony. 
 
REPORT OF STATE GEOLOGIST. 277 
 
 2. Quartz — often again coated by chalcedony ; and again on this 
 latter beautiful and minute quartz crystals have heen observed. 
 
 3. PyriL-s and Blende, the former often converted into hematite, 
 or even limonite. 
 
 4. Galcite — sometimes intergrown -with quartz, also in a few- 
 instances coated with chalcedony. 
 
 Bolomite appears to . succeed the calcite. 
 
 5. Incrustations and Kaolin. — In a few cases pyrites has been 
 observed right in the chalcedony of the outer crust. 
 
 A few acicular crystals were observed in one geode, in pure 
 quartz. These crystals look precisely as fleches d'amour, or 
 acicular crystals of Rutile, TiOj. In the hope of getting more 
 material, a final examination has been delayed. 
 
 FORT DODGE, WEBSTER COUNTY. 
 
 1. Gypsum, quite abundant. The most common is the gray, 
 massive variety ; it burns white. The snow - white gypsum from this 
 region is nearly chemically pure, and shows needles of gypsum- 
 crystals. 
 
 Separate selenite crystals, not very regular, but of the common 
 arrow - head variety, have been examined from the same county. 
 
 2. Celestine, strontium sulphate, SrOiS. — Bluish columnar; 
 no fine crystallizations. Columns vertical ; one to three inches iong, 
 the thickness of the deposit. 
 
 3. Pyrites, in globular masses. 
 
 4. WAVERLY, BREMER COUNTY. 
 
 1. Caleite, very clear, finely crystalized, hexagonal prism with 
 the first obtuse rhombohedron J R of 135°; diameter about f inch. 
 
 Calcite Geodes from this place show a fine, almost silky lustre, and 
 the rhombohedra of 83° (J R) and of 124° (f R) and also the com- 
 mon scalenohedron (R 3) together with the vertical prism. 
 
 The variety of Anthraconite is quite abundant at this place. It is 
 very fetid when struck, has a fibrous to columnar, at times radiated 
 structure ; the free extremities of the crystals show the rhombohe- 
 dron of 83° (fR). Associated with this Anthraconite is 
 
278 REPORT OP STATE GEOLOGIST. 
 
 Dogtootli spar, showing the common scalenohedron (R.3), some pro- 
 jecting fully half an inch. 
 
 With the first - mentioned hexagonal prisms of calcite occurs. 
 
 2. Barytes, bluish tables, containing small crystals of 
 
 3. Pyrites. 
 
 5. IOWA FALLS, HARDIN COUNTY. 
 
 1. Calcite, Scalenohedra (R3) and probably also (— 2 R 3), 
 terminated by the obtuse rhombohedron JR. Often one - half inch 
 long. 
 
 2. Fire-Clay, very pure; associated with a pure white marly clay. 
 The fire - clay consists of pale -reddish sand, 16 per cent; clay 84 
 
 per cent ; containing water and volatile matters 34 per cent. 
 
 The white marly clay (much more plastic than the former) con- 
 sists of : 
 
 Alimuna 27.85 
 
 Silica 26.66 
 
 Water 13.28 
 
 Giving clay 69.79 per cent. 
 
 Lime 9.45 
 
 Carbonic acid ^ 7.42 
 
 Giving calcium - carbonate 16.87 
 
 Hygroscopic water 12.00 
 
 Organic matter and loss 1.34 
 
 100.00 
 6. VARIOUS LOCALITIES. 
 
 Alum from Albia, Monroe county. 
 
 Barytes from Elk Creek, Decatur county. 
 
 Barytes from Madison county, West Line. 
 
 Calcite from quarry opposite State University, at Iowa City, west 
 bank of Iowa river. Very beautiful fundamental rhombohedra (R), 
 also having their lateral edges bevelled according to R3, and finally 
 this scalenohedron alone. In some specimens, one cavity may be 
 filled with one of these forms, another cavity, an inch or so distant. 
 
REPORT OF STATE GEOLOGIST. 279 
 
 contains the other form exclusively. The largest crystal, about two 
 inches long, very regular, R3 and R combined. 
 
 Dendrites, from Anamosa, Jones county, on slabs ; from Dubuque, 
 on an orthoceras. 
 
 JSpsomite, or epsom salt, efflorescent incrustations from near Bur- 
 lington. 
 
 Flint, Madison county. 
 
 Hematite, near Keosauqua, Van Buren county. 
 
 Pyrites, pyritohedra, from James' coal -bank, 12 miles below 
 Davenport. 
 
 Tuienmergel, very good specimens, from Webster county and from 
 Page county. 
 
 Crystallites ; these peculiar concretiona have been obtained from 
 near Burlington and Iowa City. I think they are pseudomorphs 
 after gypsum or celestine. 
 
E R R ^^ T A 
 
 Page 173, top line, for '''•Sni'face Geology" read "Geology." 
 
 Page 85» 14th linefromthe top, for '■'■class" read '■'■clay8.\ 
 
 Page 175, 13th linefromthe lop, for '■'■groiips" read '■'■group/* 
 
 Page 178, 3th line from the top, for •'■theu'' read '"'there.'" 
 
 Page 178, 10th line from the bottom, '■'groups" read '■'group." 
 
 Page 179, 13th line from the bottom, for '•'bands" read '■'■band." 
 
 Page ISO, 15th line from the bottom, for '•'modules" read "nodules." 
 
 Page lS-3, 6th line from the top, for •'■This baud'^ read "'Bslow this band." 
 
 Page 183, 4th line from the bottom, for "the conspicuous" read ''the most conspicuoiu." 
 
 Page IDl, top Hue, for "Geology" read " Surface Geology." 
 
 Page 192, 12th line from the top, for '■'mark" read "reach." 
 
 Page lifS, I7th line from tbe bottom, for "if no other than this" read "if for no other reaaon 
 
 than their " 
 Page lfl3. 17th line from the bottom, for "visited" read "viewed." 
 Page 397, 10th line from the botti>m, for "depression" read "depressions." 
 Page 198, 17th line from tht: boitom, for "Granite" read "Grant." 
 Pago 19S, 14th liMefroin the bottom, for "-are seen only" read "are best seen." 
 Page 1'J9, l'2th liref.um ihi- top, for "rills" read "wells." 
 
 Page 199, 17tU line Ivom the botiora, far ' the influences" read *Hhe same Inflaences/* "^ 
 Page 199, 6th line from ihe bottom, tor "various" read "forest." 
 Page 199, Sthlinir uodi tlie bottom, for "interspersed" read "interrupted." 
 Page 200, 15th liuo fram tUetop, coma between "horizon" and "like." 
 
GLOSSAEY. 
 
 The law authorizing the present geological survey provides that a glossary shall 
 accompany each volume of reports. < 
 
 Allumal — That -which is deposited by the washing of rivers along their course. 
 
 Amplexus — A genus of fossil corals. 
 
 Anticlinal — A given line or ridge /row which the strata dip in both directions. 
 
 Arenaceous — Sandy, containing sand. 
 
 Argillaceous — Clayey, containing clay. 
 
 Aulosteges — A genus of fossil shells. 
 
 Axophyllum — A genus of fossil corals. 
 
 Black - haw — Viburnum prunifolium. 
 
 Black- locust — Robinia pseudo - acacia. 
 
 Bluff -deposit — The formation composing the Missouri river bluffs. See 
 
 article on " Lakes of Iowa, past and present." 
 Beyrichia — A genus of minute fossils belonging to the same order with crabs 
 
 and lobsters. 
 Borers — The larvse of an insect that deposits its eggs upon the bark of the 
 
 black- locust. When the larvse are hatched they bore their 
 
 way into the body of the tree in such numbers as to destroy it. 
 Bottom — A Western term, apjiUed to the low, flat, alluvial lands so common 
 
 along western rivers. 
 Coal-measwes — A name for that assemblage of carboniferous strata which 
 
 contains the coal. 
 Conglomerate — Gravel and sand consolidated into rock. 
 Cottonwood — Populus monilifera. 
 Cranberry — common — Vaccinium macrooarpum. 
 Cranberry — high - bush — Viburnum oxycoccus. 
 Crania — A genus of fossil shells. 
 Cretaceous — The name of a geological age. The chalk of Europe belongs 
 
 to the cretaceous age. 
 Crustacean — Belonging to one of the animal sub - kingdoms. It embraces 
 
 insects, lobsters, crabs, star - fishes, &c. 
 Cryptacanthia — A genus of fossil shells. 
 'toceras — A genus of fossil shells. 
 ere — A genus of minute fossils, related to Beyrichia. 
 Drift — The formation which contains the boulders. 
 Drifting — Digging a way horizontally into, or within a mine. 
 36 
 
282 GLOSSARY. 
 
 Fauna — A term used in geology to signify the aggregate of all the animal 
 remains. 
 
 Ferruginous — Containing iron. 
 
 Fault — A break in the continuity of strata by the lifting or settling of one 
 ' part of them. 
 
 Oeodes — Hollow, concretionary, stony masses, usually lined with crystals. 
 
 Orit — Coarse sandstone. 
 
 Habitat — The naturally chosen place of habitation or growth of an animal 
 or plant. 
 
 Hydreionoerinus — A genus of fossils belonging to the same order with star- 
 fishes. 
 
 Inoceramua — A genus of foss*l shells. 
 
 In situ (latin) — In place. 
 
 Lacustrine — Formed by, or belonging to a lake. 
 
 Marlite — Limy clays, usually in indistinct layers; common among the coal- 
 measure strata. 
 
 MeekeUa — A genus of fossil shells. 
 
 Micaceous — Containing mica. ' 
 
 Nautilus — A genus of shells, both fossil and recent. 
 
 Protozoan — belonging to the lowest branch of the animal kingdom. 
 
 Pinna — A genus of fossil shells. 
 
 Shaft — A perpendicular way into a mine. 
 
 Sphagnum — A genus of mosses, -several species of which usually grow pro- 
 fusely upon peat - marshes. 
 
 Stratum (plural, strata) — layers, or beds of rocks. 
 
 Synclinal — A given line or longitudinal depression, toward which the strata 
 dip in both directions. 
 
 Timber — A term applied in the West to all native groves or bodies of forest- 
 trees. 
 
 Tomoceras — A genus of fossil shells. 
 
iN^ r> E x . 
 
 PAGE. 
 
 Adams county 66 
 
 Adair county 68. 
 
 Anamosa quarries '. . . 37 
 
 Appanoose county 40 
 
 Black Hawlt county 30 
 
 Boonsboro, coal mines ol 143 
 
 Burlington and vicinity 30 
 
 Cass county 65 
 
 Coal, Chemist's letters on 205 
 
 Coal, proximate analyses, &c., of. Prof. Hinrichs on 348 
 
 Coal - field of Iowa 163 
 
 Collections 167 
 
 Davis county 35 
 
 Decatur county 43 
 
 Des Moines, coal at city of 167 
 
 Drift phenomena in southwestern Iowa 143 
 
 Fort Dodge, coal, stone, &c., at 140 
 
 Fort Dodge, gypsum at -. 135 
 
 Franklin county .^ 119 
 
 Fremont county : 50 
 
 Fuel, Chemist's letter on 305 
 
 Geology of Raccoon river region, O. H. St. John on 173 
 
 Gypsum at Fort Dodge 135 
 
 Hamilton county 25 
 
 Hardin county 21 
 
 Hinrichs, Prof G., first report of 9 
 
 Hinrichs, Prof. G., second report of 204 
 
 Hinrichs, Prof. G., letters of. 205 
 
 Indian mounds. '■^° 
 
 1 s 
 Introductory 
 
 04 
 Jefferson county -. 
 
 37 
 Jones county ••• 
 
284 INDEX. 
 
 PAQE^ 
 
 Lakes of Iowa 151 
 
 Lead mines of Dubuque 97 
 
 List of fossils 168 
 
 Madison county .' 70 
 
 Maliaska county 91 
 
 Marion county 100 
 
 Marshall county 117 
 
 Mills county 56 
 
 Mineralogy of Iowa, Chemist's report on 264 
 
 Monroe county. 93 
 
 Montgomery county 63 
 
 Page county 47 
 
 Peat 121 
 
 Petroleum 36 
 
 Pottawattamie county 59 
 
 Ringgold county 43 
 
 Rocks, Chemist's letter on 338 
 
 Salt 74 
 
 Soil, vegetation, &c 165 
 
 St. John, O. H., Report of ._ 84 
 
 St. John, O. H., Letters of .* 173 
 
 Surface geology of middle region of Western Iowa, O. H. St. John on 172 
 
 Taylor county 45 
 
 Union county 69 
 
 Van Buren county 113 
 
 Walled Lakes , 151 
 
 Wapello county 108 
 
 Waters, Chemist's letters on 333 
 
 Wayne county , . . 40 
 
 Webster county 36 
 
 White, Dr. C. A., First Annual Report of. 5 
 
 White, Dr. C. A., Second Annual Report of 81 
 
 White, Dr. C. A., Letters of for 1866 30 
 
 White, Dr. 0. A., Letters of for 1867 91 
 

 y^T^Jy^^T"^^^--^