SUPPIEMENTARY A-ND FINAL REPORT OF A GEOLOGICAL RECONNOISSANCE OF THE STATE OF LOUISIANA, MADE UNDER THE AULSPICES OF THE NEW ORLEANS ACADEMY OF SCIE'NCES~ AND OF THE BUREAU OF IMMIGRATION OF THE STATE OF LOUISIANA, IN MAY AND JUNE] 1869. BY EUG. W. HILGARTD, Pu. D., State Geologist of Mississippi, and Professor of Agricultural Chemistry in the University of Mississippi. NEWVF ORLEANS: PICAYUNE STEAM JOB PRINT, 66 CAMP STREET. 1873. SUPPLEMENTARY REPORT. TIHE expedition of whose results the following pages contain the record and discussion, was, as will be remembered, equipped and carried out under the auspices of the New Orleans Academy of Sciences, its expenses being defrayed from funds provided, partly by subscription among the members of that body, partly by an appropriation made for the purpose by the Commissioners of Immigration of the State of Louisiana. Its object was, primarily, to ascertain the general geological features of the State, thus gaining an insight into its probable mineral resources, also; and, at the same time, to make such observations concerning its topographical, agricultural and botanical features as time and opportunity permitted, and the publication of which would serve to make the advantages offered by the State to immigrants more generally known. The personnel who volunteered for this service were, besides the writer: Dr. J. R. Walker, a fellow of the Academy, and Mr. F. Scott Miller, son of Dr. J. C. Miller, likewise a fellow of the Academy, all of New Orleans. All were well mounted, and a pack-mule was taken along, in charge of the junior member of the party, for the transportation of specimens collected on the route, at a distance from shipping points. A highly valuable suite of 250 specimens, representing all the salient features of the geology of Louisiana, was thus secured. Unfortunately, the time at my disposal was, at the outset, unavoidably limited to about thirty days; but circumstances prolonged my absence from home to thirty-nine days, of which thirty were spent on the road (from New Orleanls to Waterproof), five in preparations at the former city, and the rest going from and returning home. During twenty-eight days actually spent in the saddle, the party traveled about six hundred and twenty-five miles, thus averaging over twenty-two miles a day. At this rate of progress, rendered necessary by the limited time within which a certain problem required to be solved, it was impossible to go far into details, to deternmine doubtful questions by lengthened research, or to go back upon observations too cursorily made at first. And single-handed it would have been impossible, within this brief space of time, to reach the results which enabled me, a few months later, to lay before the American Association for the Advancement of Science, at its Chicago meeting, the first geological map of Louisiana; the details of which have, of course, received numerous corrections by the subsequent investigations of my esteemed friend Professor Hopkins, without, however, changing in [4] any material points its general features. For this measure of success great credit is due the ready and intelligent co-operation of my companions, involving, at times, a very serious sacrifice of physical comfort, and perseverance under adverse circumstances. To Dr. Walker, especially, I am greatly indebted in this respect. The geological and topographical survey of the State, under the auspices of the University of Louisiana, having been actively begun almost simultaneously, and carried forwatrd ever since by Professors Hopkins and Lockett, more at leisure and with more ample means: I have thought it unnecessary to record here much information of a general character, that has already found a more extensive and profitable discussion in the reports made by these gentlemen. The detailed itinerary and narrative is also omitted, both as being of minor interest at this time, and as having already received some publicty from the pen of Dr.Walker, as-well as in my preliminary report. I have also thought it best to omit such theoretical discussions of geological questions as have received a sufficient consideration in my prior publications, to which 1 refer those readers who may be desirous of obtaining fuller and more detailed information and discussion.* For the chemical work which has so materially contributed to the interest and elucidation of the results, I amn indebted to Mr. R. H. Loughridge, the assistant in the chemical department of the University of Mississippi, now Assistant State Geologist-the work having been performed at a merely nominal compensation. While regretting the delay in the elaboration of this report, which has been caused by the accumulation upon my hands of the material of prior investigations, in consequence of the numerous pressing demands upon my time, of other professional duties: I trust that it may still be of undiminished interest, as the faithful record, and discussion by the light of later investigations, of the researches rendered possible and fruitful, by the earnest efforts and liberal support of this Academy. THE ATTAKAPAS PRAIRIES. The prairies near New Iberia have pretty stiff, black soil, which appears to become more and more calcareous as the coast is approached. See Report on the Geology and Agriculture of Mississippi, 1860. On the Qaarternary ornmationis of Mississippi,, American Journal of Science, May 1866. On thie Tertiary Formnations of Mississippi and Alabama, ibid., January, 1867. On the Geology of Lower Louisiana and the Rock Salt Deposit of Petite Anse, ibid., January, 1869; iinal Memoir on samne, Smithsonian Contr. to Science, No. 248, June, 1872. Prelimitary Repor't of a Geological Reconntoissance of Louisiana, DeBow's Review, September, 1860; American Journal of Science, November, 1869. Report on the Geological Age of thee Mississiippi Delta (examination of the shells brought up from the Artesian well bored at New Orleans in 1856.) Report of U. S. Engineer Department, 1870. On the Geology of the Delta, and the Mud Lumps of the Passes of the Mississippi, American Journal of Science, Vol. 1, 1871. On the Geological History of the Gulf of Mexico, ibid., December, 1871. On some points in the Geology of the Southiwest, ibid., November, 1872. See also the reports of the Geological and Topographical Survey of Louisiana, by Professors Hopkins and Lockett, published in the reports of the Superintendent of the University of Louisiana. [5] Thus, in the prairies off Petite Anse and Grande C6te, or Weeks' Island, we commonly find underlying the usual twelve to fifteen inches of soil proper, a subsoil layer completely filled with "' white gravel," i. e., calcareous concretions from the size of a pea to that of a pigeon's egg. This layer, as seen in ditches, is from six to twelve inches thick; beneath it lies either a loamy silt, with spots of bog ore, or else a rather tough bluish clay, which forms the floor stratum of all the more southerly portion of the Attakapas prairies South of New Iberia the latter are altogether treeless in their natural state, save here and there a honey locust on the low- ground; the China tree and sycamore have, however, been l.rgely planted near the homesteads, with a view both to shade and fuiel. W~ithin a few miles of the Te'che the surfaace is almost a (lead level; so that after a heavy rain the water stands on the surface for soine hours, seemingly at a loss as to the proper course to take for drainage. Gradually, however, it gathers into more or less definite shallow depressions (nmawais) and channels or;" coulees" (as they are called by the Creoles), of which the bayoun Cypres Mort is a very characteristic example. Until within a few miles of the coast marshes, its course is defined only by a green band of reed-grass and cat tail, the water remaining, ordinarily, invisible, and its motion so slight that the duck-weeds (Lemna) anld l zolla form a dense sheet of greel, variegated with olive and red on its surface. It traverses, in its course, some of the most highly prized cane lands of this gard en of Louisiana. A specimen of virgin prairie soil, taken about midway between Petite Anse Island and New Iberia, gave the following results: Depth, ten inches without change of color; below this depth it becomes more greyish, with an increasing amount of rounlded, chiefly ferruginous concretious (or black pebble); gray loam at two to threet feet; vegetation, grasses, mainly Panicumr sp., and Andropogon (broom sedge), with Vernonia (iron weed). Color, deep black; soil quite heavy; not as much so as the prairie soils of Mississippi and Alabama, but does not crumble on drying, like the latter. Saturated with moisture at 12.8 degrees centrigrade, it lost 10.6 per cent. on drying at 2040. Dried at this temperature it consisted of: Insoluble matter...............................67. 21 Soluble silica-...... ----- -.......... —-. ----—.... 9.96 77.17 Potash... —----—. —----------------- -—.......... —--.21 Soda.... —....... —------- -... —------------ - -- -....17 Iilne -.. -— _,,,, _,..-,, —--- _ _ _ —---- --—.... - --._...*.. — - 1.74 ma agnesia. —............................... —------------—... — --- --—. 1.48 Br. oxide of Manganese.......................... 0.27 PeroSide of Iron................................................... 2.78 Alumina........................................................... 4.83 Phosphoric acid.................................................... 0.21 Snlphuric acid.................................................... 0.11 Carbonic acid..........-..................2............ 2.06 Water and organic matter.......................................... 8.60 99.63 [6] The result of this analysis was most unexpected to me. The com1position of this prairie soil dififers widely from that of prairie soils of other States, in the small amount of both potash and alumina. Mississippi prairie soils yield from three to four times as much; the latter representing, approximately, the amount of clayey ingredient present. This shows a very large proportion of the soil's bulk to be made up of fine silex, to which rather than the clay present, its heaviness is owing. And as the clay is usually, in the Gulf States at least, the carrier of potash, the reason why the proportion of the latter is so small as to be even below the amount shown by the analysis of many pine wood's soils, becomes obvious. ~How then, it may be asked, are we to account for the well established high fertility of this soil? The explanation lies, doubtless, in the large amounts of lime, phosphoric acid and organic matter present. The former vouches for the largely available condition of the potash, and assures us that the alumina dissolved in the analysis nearly represents the amount of clay in the soil. And it imparts to the soil that thriftiness which belongs only to soils capable of promptly converting all vegetable matter into true, black 1' humus."1 As to phosphoric acid, one-quarter of one per cent., 0.250, is the maximum amount I have as yet found in the best soils of Mississippi, and this is rarely reached. The soil before us contains one-fifth of one per cent., therefore a very ample supply. As to vegetable matter, the amount of chemically combined water belonging to the ferric oxide and clay cannot exceed two and one-half per cent. Of the 8.6 per cent. of " volatile matter," therefore, fully six per cent. are vegetable matter or humus; a very large amount for an upland soil. This, again, assures the thriftiness of the soil, by securing a large supply of ammonia, by rendering the soil highly retentive of moisture, absorbent of heat, and yet easy to till, and not liable to injury from drouth. Yet the comparatively small percentage of potash warns us that continued culture in cane, without return to the soil, whereby potash is mainly drawn upon, will be sure, before long, to bring about exhaustion of the soil of its available potash, and consequent deterioration of the sugar crop. The ulnnecessary withdrawal, annually, of almost the entire ash ingredients of the bagasse is, therefore, a very serious evil, to, remedy which, consistently with the possible expenditure of labor at the critical time of the sugar harvest, is a problem well worthy the consideration of competent inventors. It is interesting to compare with this prairie soil, and with the soils of the higher prairies of the Cote Gelee and Opelousas, that of the uplands on the islands. I have selected for this purpose the subsoil loam from VeIek's Island, taken on the southward (exterior) slope, some distance west from the lower dwelling house, where it forms a regular stratum some six -feet thick. It is of a tawny brown tint, not very clayey. Saturated with moisture at 2() 5~ Cent., it lost at 2010, 8.96 per cent. of moisture, and consisted of: [7] Soluble matter..- -. - 73.20 82.32 Soluble silica.......... 9.12 Potash-.......... 0.40 Soda-0.6..... d.... Z..... 0.06 Soda.............................................................. 0.06 Lime - --- ---- ---------—.....0.20 Magnesia.-..-... —------—. —------------- 0.82 Br. oxide manganese.-........ —--- -... 0.13 Peroxide of iron... —-...-.................. —.......... -—. 4.76 Alumina.......................................................... 75 Phosphoric aci-d................. 0.11 Sulphuric acid.... — - - 0.03 Volatile matter............. -4.02 100.66 It will be seen that this loam differs in several material respects from the Iberia prairie soil, but the detailed discussion is best deferred to another place, in connection with the subsoils of the higher prairies. The soil of the Cypres Mort Woods, also profusely fertile, is of a lighter nature, contains a good deal more coarse sand, and is, doubtless, the result of the intermixture of the prairie soil with recent marine alluvion. It has not been analyzed as yet. Approaching the Teche, the prairie soil assumes a somewhat brownish tint, probably from the admixture of some of the red clay and loam, which form the bed and immediate valley of the Tefche, as they do of Vermilion and Red rivers Northwestward of New Iberia, on the Vermilionville road, the black prairie continues, with apparently little change, for about twelve miles. The soil, as shown in road-side washes, is from twelve to eighteen inches in depth; then follows a yellowish subsoil, occasionally with some black (ferruginous) gravel, but not nearly as much of the calcareous kind, the liminess of the soil decreasing, apparently, as we proceed northward. Small woody strips along the coul6es consist of Ilackberry, Sycamore, Honey Locust, and near the bayou, of Live and other lowland Oaks. Wells in this region are mere pits, eight or ten feet deep, with bad water. Ponds furnish the supply for stock. A I COTE GELEE. Beyond the point mentioned, begins the CBte Gelee country, with a slow, but decided ascent from the black prairie. Though still a prairie country, it is more rolling, with fewer ponds (marais) on its surface, and well defined channels for its water courses. On the slopes a brownish yellow or tawny subsoil loam crops out, often mixed with or underlaid by black gravel; the soil is not of as dark a fint, nor quite so deep, being on level grounct about ten inches to the subsoil properAn analysis of the latter is given below, alongside of that of the Opelousas prairie, with which it agrees very closely in composition. Wells are eighteen to thirty feet deep, finding water not in sand, but in crevices in the gray or mottled loam,* mostly where the latter'This loam, I conceive, to be the equivalent of stratum No. 5, of my Port HIudson profile, with which it is about on a level. See Am. Jour. Scien(e, Jan. 1869; Smithsonian Contr. to Knowledge, No. 248. [L8 touches blue clay or loam, which forms the bottom. The water is iimy, not very cool, but drinkable, and probably not unhealthy. The vegetation of the Cote Gelee prairies, like that of the Grand C6teau and Opelousas region, is remarkably little varied. Two or three species of Paspalum, with a sprinkling of Andropogon or broom sedge, dispute the ground with white clover. The Iron weed and Wild Indigo (Baptisia), are the chief representatives of herbaceous growth, added to which is in most regions the Eteleniunt tenuifoliumn or bitter weed, whose bright green, grass-like leaves often grievously disappoint the hungry beast of burden, and impart an intensely bitter taste to the milk of cows, feeding on it for want of something better, From the prairie there is a sudden descent into the valley of Bayou Vermilion; on the slope we find the same dun-colored loam observed all along, underlaid by somewhat sandier material with black gravel. But the bed of the stream and its flood-plain are formed by quite a different material-a rather tough, red clay, evidently the congener of the Red River and Teche deposits. On its right (north) bank, the river is here bordered by a level wooded hommock, some thirty feet above the flood-plain, about a mile wide, and timbered withWater, Basket, Scarlet and Live Oak, Magnolia, Poplar (or Tulip tree), and much Sweet Gum; the soil lighter than that of the prairie, but excellent. The wells at Vermilionville are thirty to forty feet deep, good water being found in sand underlying the yellowish clay or loam. THE OPELOUSAS PRAIRIES. There is a very great sameness in the general features of the country from the Cbte Gelee to Opelousas, and beyond to Ville Plate, where we reach the northern limit of the prairie region. Apart from the usuallocal differences resulting from diversity of level and position, the general change, as we advance northward, is a very gradual diminution of the depth, and intensity in the tint, of the prairie soil, showing a diminished amount of vegetable matter; while at the same time, the subsoil appears at the surface more frequently, the more as the country is more rolling, while marais and ponds become more scarce. Concurrently there is an obvious diminution of the thriftiness of the soil in its natural condition; although under high cultivation, (which unfortunately, it rarely receives,) it makes excellent crops both of corn and cotton. About halfway between Opelousas and Ville Plate, on the plateau, dividing the waters of Bayou Cocodrie from those of the Mentau, specimens of soil and subsoil were taken in the open prairie. I regret that the limited means at my command did not permit either of taking more abundant specimens of soils, or of having even all of those collected subjected to analysis. A single specimen analyzed cannot, with any degree of confidence, be considered as giving a fair insight into the general characteristics of the soils of an extensive region. The soils, however, are more variable than the subsoils; the latter being, in the case before us, a regular geological stratum of considerable uniformity [9j of character. From this the soils are derived by processes somewhat variable in kind and intensity; hence it seems fair to conclude that the examination of the subsoils is better adapted to convey information of a general character. For this reason I have, in most cases, preferred the latter in the present investigation. The surface soil, at the point mentioned, was abont twelve inches deep, of a grayish'black tint, not very clayey. The vegetation, same as above stated iii general. The soil, saturated with moisture at 23.9~ Cent., lost 5.42 per cent. at 2040 Dried, at this temperature, it consisted of: Insoluble Matter.............................86.81 9015 Soluble Silica- 3.34.. 190.15 Potash. Sii..................................................... 0.19 Soda............................................................ 0.14 Soda --- ----- ---------- ----- ----- ----- ----- ------ -------—,,,,,,. -r r 0.14 Lime.............. —-—. —..............- 0.15 Magnesia-..............................-............................ 0.23 Br. oxid Mangauese... -..-......-. 0.09 Sesquoixid of Iron..-.............................................. 1.94 Alumina ----.. —--------- —.2 —-------------------—. —...... 2.09 Phosphoric acid...-..........0.23 Sulphuric ".......................-......................... 0.04 Water and organic matter........................ 4.82 100.07 The subsoil was taken at fifteen to eighteen inches depth; color, a tawny brown. Saturated with moistureat 2140 Cent., it lost at 2040, 8.94 per cent. of water That of the C6te Gelee, taken near its southern extremity, on a hillside, of the same tint, saturated with moisture at 19.60 Cent., lost at 2040, 7.78 per cent. of water. That of Grande Cbte or Weeks' Islands, which I again place here for comparison, at 20.6, absorbed 8.97 per cent. of moisture. Their composition was found as follows: SUBSOIL LOAM. Opelousas Ckte Gel6e. Grande Ckte. Prairie. Insoluble SiMatter......... 7 —481705.39 83.70 73.20 82.32 Soluble Silica... 6.96 8.31 9.12 Potash............................ 0.32 0.33 0.40 Soda.. —------- 0.01 0.02 0.06 Lime. --........................... 0.25 0.13 0.20 Magnesia..-... 0.60 0.69 0.82 Br. Ox. Manganese................. 0.08 0.15 0.13 Peroxid of Iron.................... 4.79 4.29 4.76 Alumina........................... 7.72 6.48 7.75 Phosphoric Acid.................. 0.15 0.16 0.11 Sulphuric "..... 0.01 0.05 0.03 Volatile Matter..4.36 4.54 4.02 100.00 100.54 100.66 The most obvious difference between these materials and the prairie soil from Iberia, is the very small amount of lime, being over six times less than in the latter. Hence the comparative unthriftiness. The analysis of the surface soil also shows a slightly smaller amount of 2 [ 10o potash, and very much less of vegetable mold. Doubtless the application of lime or plaster would result in a very great improvement. But for so close a soil, in which roots can descend to moderate depths only, the amount of potash is quite small-as, in fact, it seems to be in most Louisiana upland soils. The phosphates, likewise, are in smaller quantity, yet not deficient. As in the case of the Iberia soil, there is here a very great predominance of fine siliceous material over the clay; and assigning to the latter as well as to the ferric oxid, their usual quota of combined water, we have remaining but 3.65 per cent. for vegetable mold. Hence the slight capacity for absorbing and retaining moisture [about half of the Iberia soil, and hence, again, a comparative want of thriftiness, resulting in part from an inferior power of absorbing ammonia from the atmosphere. As regards the subsoils, the close agreement of the analysis of three specimens, taken at random, so far apart, argues not only an equally close genetic relation, but is also strikingly illustrative of the groundlessness of the general objection urged against the utility of soil analyses, on the score of the supposed impracticability of obtaining representative specimens. Similar results have been obtained in the investigation of the soils of Mississippi, and can, doubtless, be reached in any region where the subsoils and soils are directly derived, by disintegration, from wide-spread formations; especially if the materials be very fine, and, therefore, thoroughly intermixed. No such uniformity of results, can, of course, be attained with manured soils, or with such as have been recently in. cultivation; nor, for obvious reasons, can the results of the analses of soils, as a rule, agree as closely as those of subsoils. Of the sub-soils before us, those of the C6te Gel6e and Opelousas prairie agree most closely as to the two chiefly important ingredients, viz: potash and phosphoric acid; but they differ quite materially as regards the amount of lime, of which the latter contains twice the quantity found in the former, which, therefore, at the point sampled, would be the less thrifty of the two. This does not'seem to accord with experience in cultivation; but then, a single specimen from each region cannot determine such questions. In all three, the amount of potash is not over one-half of that usually found in upland subsoils in Mississippi; agreeing with the result observed in the Iberia prairie soil. The Grande C6te soil is richer in potash, but. poorer in phosphoric acid, than the two upland prairie soils. In the almount of lime it stands between the two others; but in none of the three does the a, mount of the latter substance approach that contained in the Iberia prairie soil, whose subsoil, were it is available for direct comparison, would show an amount even considerably larger. The same remark holds true of the magnesia, though this substance does not seem to be deficient in either. Yet, although inferior to the best, there can be no doubt that, with proper culture, these lands can be made highly productive. As yet, their surface has but been scratched, and mostly with indifferent imple ments. With their balmy climate and easy tillage, unmenaced by washing and floods, the COte Gelee, as well as the Opelousas prairies, cannot fail to become a second "1 garden," whenever the railroads now in course of construction, and others that will follow them, shall place this region in easy communication with the world's market, and with the makers of subsoil and steam plows., THOSE MOUNDS. From the dividing plateau just mentioned, the prairie slopes off to wards the heads of Bayou Cannes, and the very level prairie on the edge of which "' Flattown"' is situated. On this prairie we first observe, in considerable numbers, those singular rounded hillocks which dot so large a portion, both of the prairies and the wood lands of Southwestern Louisiana, and adjoining portions of Texas. With a maximum elevation of about two feet above the general surface, they have a diameter varying from a few feet to twenty or thirty; their number defies calculation. They do not show in their internal structure any vestige of their mode of origin; or rather, being totally devoid of structure of any kind; they merely prove by their material that there has been a mixing up of the surface soil with from two to four feet of the subsoil. They are altogether independent of formations underlying at a greater depth, and it seems impossible to assign to them any other origin than that historically known of their brethren in Texas, viz: that of ant hills. As to the physical or moral causes of the wholesale slaughter or emigration of this once teeming population, deponent saith not. Perhaps some of the aboriginal Attakapas tribes might, if consulted, still be able to bear testimony on the subject. CHICOTVILLE. The wooded uplands near Chicotville are evidently of a mixed geo. logical character. While in some localities, wells and hillsides exhibit the unmistakable drift, in others, wells strike only materials equally characteristic of the Port Hudson group, such as fetid black and blue clays, fossil wood, leaves, etc. Doubtless the deeply-eroded surface of the drift formed in this region, a somewhat indefinite or deeply-indented shore-line of the Port Hudson marshes; hence a complicated interlacing of ridges, basins, and estuaries of the two formations. At some points, doubtless, the Grand Gulf clay and "' rotten" sandstones may also be struck, as is the case to the westward of Pine Prairie, o thie waters of the Nezpique. The unalloyed drift covering the Grann Gulf rocks may be seen, according to Hopkins, a few miles northd ward of Chicotville. PINE PRAIRIE. From the ridge or plateau on which the latter place is situated, a few miles' gradutal descent southward, thlrough oak uplands, with a ipale yellow loam subsoil, takes us to the Pine Prairie, a gently rolling plain, dotted with clumps of Long-leaved Pinelt hich; if not eqtUal in [ 12 3 size to some of its brethren in the woodlands, is equally far from the dwarfed condition in which we find it on the " meadows" of the Mississippi sea coast.* These pine prairies, of which this is the most easterly outlier, form an important ieature in Calcasien, as well as in portions of Texas. The soil here is greyish, ashy, full of bog ore spots; subsoil at six to eight inches, is sometimes a mass of black gravel, and underlaid at the depth of a few feet by a putty-like, very siliceous clay, almost impervious to water. The soil is very poor, the growth of grasses coarse, such as Luzala, Carex, Juncus, Andropogon, some Pa.spalurn; while the A letris ourea, Allium mutable, Livum Virgini.cum, Baptisva leucophcea and leucantha, Psoralea melliotoides, and a variety'of Polygalae, impart to this barren prairie a much more cheerful aspect than is that of the green and fertile, but flowerless prairies of Opelousas. It is only by the aid of manure, however, that any crops can be raised on this soil. Beyond the prairie we enter upon a belt of long-leaf pine hills of the usual character, possessing a yellow loam subsoil of fair fertility (as a pine woods soil); the pine timber is remarkably fine, and is occasionally replaced by short-leaved pine and oaks, indicating a stronger soil. This rolling timbered belt, borders the Nezpique on the east, with a width of from one to three miles. THE "ST. LANDRY MARBLE." In the bed of the Nezpique, as well as in that of Boggy Bayou, there are exceedingly characteristic outcrops of the materials of the Grand Gulf group, viz: solid greenish clay, and the jagged clay-sandstones, so common in the southwestern counties of Mississippi. But a few hundred yards from such outcrops is the now well-known limestone outcrop, which subsequent observations have enabled me to determine as being of cretaceous age. An analysis of this limestone will be given further on; it is remarkably pure, of a peculiar horizontally banded and fissured, structure (whence it has received the name of "' St. Landry Marble," a polished specimen of some beauty being in possession of the New Orleans Academy), and of fetid bituminous odor when struck. It is exposed in pits, dug a2t two points, about a quarter of a mile apart, a thickness of eight feet being visible; its dip here is about 30 degrees W. 40 S. Weathered surfaces show the horizontal structure and a granular, concretionary texture, but not a trace of fossils. Of the extent of this deposit nothing is known; but from the thickness and solidity of the portion exposed, it seems likely that enough is there to supply Southwestern Louisiana with:excellent lime for a long time to come. In an agricultural point of view, this is of especial importance, and will not fail to be appreciated whenever the long hoped-for railroads shall have put this now isolated region in communication with the outside world. -Mississippi Report,. 1860, p. 370. [ 13 PINIE FLATS AND "BAY GALLS." West of the NezpiquS, the pine woods are much less undulating, and the soil more whitish; and as we advance westward, they become almost a dead level, and ftll of boggy patches with crawfish holes and aquatic plants; among them the Asclepias pa-upercula, the vermilioncolored Milkweed of the seacoast marshes. The soil is whitish and very poor, fit only for pasture, and, perhaps, rice culture. Frequently there is a, dense growth of Candleberry (MIyrica cerifera alnd Carlinensis), EBay Galls (Laurus (Jarolinensis), and a variety of Whortleberries (Volcinium); and where these prevail exclusively, we have impenetrable thickets, popularly designated as "1 Bay Galls," the undisputed resort of the bear, panther and wild cat.-Of these there are two main bodies. One on the east of Calcasieu river, in Townships 3 and 4, Ranges 2 and 3 west; is about fourteen miles long, and half as wide at its widest portion, of a spectacle shape, and distant about a mile from the Calcasieu river; the trail from Chicotville to the Bundick's Creek settlement crossing it at its narrowest point. It is drained by the western branch of Beaver Dam or Nezpiqu6 Creek. The other " Bay Galls 7 tract lies nearly opposite, is of about the salme length, north and south, as the other, but of a regulalr oblong shape, only five miles in greatest width, and is drained by the heads of Mill Creek. Almost the entire tract traversed from the Nezpiqucl to the Calcasien river, is uninhabited and uncultivated, save by crawfish, which bring up a siliceous subsoil, often perfectly white, putty-like, but mixed with small rounded concretions of bog ore. Near the river the land becomes somewhat higher and dryer. The bottom is over a mile in width, much subject to overflow, but very productive. The timber is very prevalently Beech, also Magnolia, Bay, Sweet Gum, etc. A beautiful shrub, the Styrax Grandifolium (just in bloom at the time), is quite abundant. The present deposit of the river is rather sandy; but the more ancient material in its banks is a quite heavy bluish clay, with ferruginous spots, such as is formed in Boggy Bayou and elsewhere, by the disintegration of the Grand Gulf clays. No steep bluffs of any consequence, and hence no outcrops of the older strata, seem to occur on this portion of the river's course. But near the mouth of Mill Creek there is a small natural waterfall, which from the description and the nature of the case, is doubtless formed by the resisting Grand Gulf clays or clay-sandstones; such as cause similar phenomena elsewhere. THE CALCASIEU PRAIRIE. Near the line between townships 5 and 6, range 4 west, the level pine woods become more open, the pine smaller, and by a gradual transition we pass into the open prairie, dotted here and there with clumps of pine, which generally occupy some of the singular mounds before referred to. The pine prairie continues for about five miles, and is unoccupied save by herds of cattle; the houses of the herdsmen or 1.4 1 owners being in sight along the edge of the belts of timber which skirt the water courses on either side. Farther south, clumps of Black-jack and Post-oak mingle with, and gradually replace, those of pine. Around the heads of Serpent Bayou (which deserves its name so far as a redundancy of snakes is concerned), formed by extensive swampy flats, there is a belt of woods with an excellent soil. In these flats (the resort of numberless water-fowl), as well as in the lower levels of the open prairie, the usual place of Alder and Dwarf-willow, is occupied by the Styrcax pulverulenta. In the former localities it forms bushes five and eight feet high; in the latter it simulates the Salix tristis of the upland barrens, both in height and forlorn, dusty aspect. Beyond the woody belt we again emerge upon the open prairie, dotted with c!umps of pine and oaks, and countless herds of cattle and horses, but no settlements until we again approach Serpent Bayou. The soil is manifestly better than farther north, a species of Paspalum (barbatum?) called "' Gazon," by the C(reoles, forming the predominant pasture grass; which is highly prized by the stock raisers, especially for winter pasture. Pretty good well water is obtained here at fifteen to twenty feet. Serpent Bayou has little bottom proper, but is bordered by a narrow strip of black semi-alluvial prairie. The black soil is six to eight inches deep; it is sparsely timbered with Sweet Gum and Willow Oak, and seems quite fertile. South of the crossing of Serpent Bayou, the prairies resume their usual aspect; and about three miles from the bayou, I took a specimen of the soil, avoiding the imounds in the open prairie. VEGETATION: Clumps of Black-jack and Post Oak, and long-leaved Pine, scattered over the prairie. On the grassy surface, the prevalent plants are the two or three oft-mentioned species of Paspalum, some iLuzuzla Juncus7 Andropogon; Leptopoda fimbriata, Obeliscaria lacciniata, Ricdbeckia hirta, Echinacea purpurea, Silphium squarrosum;' Baptisia leucop2hcera, Psoralea melilotoides, Minmosa strigillosa. Polygula, two species; S'tyrax pulverulenta. Depth taken, ten inches. Soil gray, somewhat ashy, with brown ferruginous spots, and small particles of bog ore, which sifted out, amounts to 1.5 per cent. Saturated with moisture at 13.40 Cent.~ it lost 3.16 per cent. of water at 2040, and thus dried consisted ofInsoluble Matter — ----------------—..,.i —— 92.63 94,66 Soluble Silica................................................ 2.03 Potash........................ 0.15 SodaL......................i.. - -—.......... 0604 Line................................-...................i...... 0. 26 PViheosphoric 0.04 Alumina......................................................... 1,7 Sulphuric.............................................. 006 Water and Organic atter........................................... 2.61 io00.2 [ 15 ] According to this analysis, this soil is not as poor, on the whole, as might have been expected; save as regards phosphates and magnesia, in which it is very deficient. It is sadly in need of something to render it more retentive, i. e. clay or vegetable mold; but if properly drained, might be susceptible of profitable improvement and cultivation by some green manuring and use of bone-meal. Like similar soils in South Mississippi, it now bears only small-seeded plants; there being a want of the seed-forming ingredients. As we advance southward, we occasionally find sandy ridges, timbered with rather an indifferent growth of pine, crossing the road; and between these, wet fiats, in part even peopled with alligators, become more frequent. At the same time the herbaceous vegetation assumes more and more the features of the coast region, in the appearance of the Flowering Grass (Lichromena), and other plants of similar import. LAKE CHARLES. The prairie continues almost unchanged in character up to English Bayou, in which we find outcrops of a stiff calcareous clay, lying but a few feet beneath the general surface. On crossing the bayou, the clumps of trees disappear, the prairie being a perfetly level, treeless plain, with a darker and heavier, and evidently better soil, on which fine crops of corn are grown. At several points on Lake St. Charles, near the town, there are outcrops of a stiff, red laminated clay, near the water's edge. It is generally overlaid by ten to twelve feet of indefinite sand strata, and greatly resembles some of the clays at Cote Blanche.@ Overlying the sand and immediately beneath the subsoil, lie two and-a-half to three feet of gr'ay "joint" (i. e. massy) clay, often with calcareous concretions. The same strata are, of course, struck in wells, sometimes with oysters and other marine shells; and the upper. clay stratum with calcareous concretions crops out repeatedly in washes, on the road from Lake Charles to the Sulphur mine. The phenomena at the latter point, as well as the general features of this region, having already been sufficiently described heretofore, by others as well as myself,'F I will merely add that the examination of two large shell-beds on the lake led to the same conclusion already reached regarding those on the Mississippi coast, viz: That being full of the vestiges of human handiwork, such as pottery and charcoal, and consisting almost entirely of edible shells (G,,athiodon mainly and Unio), with occasional bones of small animals, and a few land-snails (doubtless accidentally introduced), they must be considered as the relics of human efforts to sustain life at the expense of the bivalve creation.'Smithsonian Contr. to Knowledge, No. 248. tNOTE. —See my "Preliminary Report of a Geological Reconnoisance of Louisiana." in DeBow's Review, for Septenmber, 1869. Also, Amn. Jour. of Science, for November, 1869; and the Reports of the Geological and Topographical Survey of Louisina:m, by Professors Hopkins amnd Lockett. I 16 1 I will also remark that while, as a rule, the bottoms of the Calcasieu and Sabine, above the latitude of Lake Charles, do not materia,lly differ from those of other rivers in the Gulf States, although usually laid down on maps as skirted by broad marshes; there are on the West Fork of Calcasieu some grassy bogs resembling sea-marsh in their aspect; as is the case on the main Calcasieu below the lake on ]Bayou Chouplque, and others in that region. NORTHWEST CALCASIEU. North of the West Fork, level pine woods, with occasional bogs or small prairies, prevail with little change save a gradual rise fromn the sea-level, and slightly greater undulation as we progress northward. Vegetation is about the same as in the boggy pine woods near the' Bay Galls." Quite a variety of Polygale occurs; also the beautiful Rudbeckcie mnaxirma, the Styrax pulverulernta, too, is occasionally to be seen. On approaching Dry Bayou, hills appear, and after crossing it, the plains of the coast are changed into gentle rolling pine woods. The marsh milkweed disappears, but the Dichromera continues, and with it occur the Eriocaulur villosunm and decangulare, which were not observed farther southwest of the Calcasieu. Here, also, the Sarracenia variolaris, or Pitcher-plant appears, but not the S. purpurea. The Stillingia sylvatiea (Queen's Delight), Valeriana (Paucifiora?) and Cnidoscolus stimulosus, (here often three feet high, while in Mississippi it rarely exceeds one foot,) are quite prevalent here as well as more or less northward to Ried River. Except in so far as the country gradually becomes more undulating as we advance northward, there is very little change in the face of the country (the pine forest being broken by settlements only ant long intervals), until we approach the base-line in R. 9 W., where we find the regular "Orange Sand" pine hills with gravel, red hard-pan and ferruginous sandstone cropping out on the abrupt hillsides. Springs, which are very rare farther south, here flow abundantly, being shed by gray pipeclays forming the base of the hills; and a few mliles farther on, near the mouth of Miller's Creek into Taylor's Creek or Bayou Foury, the Grand Gulf clay forms high bluffs of very characteristic material. Traveling, as the party did, mainly on a dividing plateau, where outcrops could not be found, the line between the Port Hudson and Grand Gulf territory could not be directly determined. The line as originally laid down by me, and adopted by Prof. Hopkins, in his Geological Map of the State, is, therefore, based upon the connection of the outcrops near Chicotville, then near the mouth of Mill Creek into Calcasieu river, and the point on the Sabine (Salem), given as the limit between the quaternary and tertary, by Prof: Buckley, of Texas. In Mississippi and East Louisiana, likewise, this limit is difficult to determine, and in a measure arbitrary, since the two formations lie conformably, or nearly so, in a level country where wells or accident only can give access to the more ancient strata. Probably outcrops [ 7 ] of the Grand Gulf clays may be found on Lower Bundick's Creek, on the Little Calcasieun or the West Fork. THE ANACOCO REGION. After crossing Bayou Zoury, the country again becomes level, with a very heavy clay soil of a red or pale tint; small Black-jack appears among the Pine and Sweet Gum in the lower places. Immediately beyond Huddleston or Petersburg, we meet patches of dark-colored prairie soil, with Crab-apple and Wild Plum; small calcareous gravel appears in roadside washes. Further on, the prairie soil appears in larger patches, irregularly distributed along hillsides and in valleys, as a consequence of its origin in a stratum of clay marl, which crops out in branches a few miles north of Huddleston. This stratum is about five feet thick, and the exact counterpart of the calcareous stratum first observed by me on Pearl river, in Marion county, Mississippi (Barnes' marl).* Here, too, it is substantially a heavy greenish clay, irregularly traversed by veins of concretionary carbonate of limne, of the "Agaric mineral" character; rarely somewhat crystalline. Of this it contains probably from four to eight per cent.; but n o where could I discover a trace of a shell, or any other fossil. Where this stratum crops out on a hillside, it forms by its disintegration and sometimes intermixture with the sandier materials washed from above, a streak of black calcareous soil, easily tilled, and highly productive. Where, as on the Anacoco prairie itself, the disintegrated marl stratum forms the surface, the soil is heavier, but from its tendency to crumble by alternation of wetting and drying, not difficult to cultivate if plowed at the proper time. It produces forty bushels of corn and a bale of cotton per acre; the cotton is small but well bolled, not much subject to rust, and the soil lasts remarkably well so long as it is not washed away, which is apt to happen-though it is rarely plowed over four inches deep. Above as well as below the calcareous stratum, lie tough clays, giving rise, respectively, to red and pale-tinted "6 hog-wallow" soils, said to be of very little "account"-difficult to till, and unthrifty. Some hillsides, when freshly plowed, have a very variegated appearance; the common yellow loam soil, perhaps, being on top; next, the red " hog-wallow;" below it a coal black band of prairie soil, which in its turn gradually shades off into a pale, unpromising clay, at the foot of the hill. Bodies of land on which this soil prevails, varying froml a few acres to several sections in extent, occur sporadically at numerous points between the West Fork of Anacoco and the heads of Calcasieu riverhow much further east, I have been unable to learn. It is noticeable that while in the southern portion of their region of occurrence, these patches mostly lie at or near the level of the creek bottoms, they rise higher and higher on the hillsides as we advance northward; owing, doubtless, to a slight southward dip of the stratum from which their soil is derived. At John Smart's, section 33, township 3, range 9 west, * See Mississippi Report, p. 179. 3 [ 18 1 it forms the crest of a ridge bordering Prairie Creek on the eanst, and thence extends, with a width of from one-half to one mile, for about three miles along that stream. The blactk soil here is about twenty inches deep without sensible change. In washes, we observe the calcareous clay or marl forming the subsoil for a few feet, when a heavy non-calcareous clay is struck. Rocky knolls and spurs showing outcrops of the characteristic clayey sandstones of the Grand Gulf group, occur occasionally on the ridges in the prairie district. Between Prairie Creek and the West Fork of Anacoco, these outcrops become more abundant, and the heavy clay soil frequently appears on the hillsides. But it is non-calcareous, and bears a poor scrubby growth of Black-jack Oak, while the summits of the ridges are of a sandy pine-hill character. At Kirk's Jtill, on the East fork of the Anacoco (section 10, township 3 north, range 9 west), we have a long hillside outcrop showing a great variety of the clays and " rotten" sandstones of the Grand Gulf age. Between the two prongs of the Anacoco we have a rather level pine woods plateau, with occasional outcrops of gray clays on hillsides, giving rise to a poor, stiff, tawny soil, and at times, the heavy red subsoil already mentioned. On the hilltops, the Drift often overlies very characteristically. A small tract of slightly calcareous clay soil occurs near the slope towards the West Fork, but is timbered with small Black-jack Oak and Pine-there is no black prairie. On the stream itself, there appears the peculiar sandstone with grains ilbedded in an opalescent matrix, so characteristic of the outcrops at Grand Gulf. After crossing the West Fork of Anacoco, we find for some distance only sandy pine hills. But soon the Grand Gulf clays reappear, and on approaching within a few miles of the Toreau, outcrops of " rotten" sandstone become very common on the brows of the hills, which become quite high and abrupt. At one point, a high and steep hill presents on its slope a complete assortment of all the sand and claystone materials of the group, observed by me in Mississippi and LJouisiana. But neither here nor anywhere in the area of the Grand Gulf group, as here traversed, was there any trace of zoogene fossils to be detected. Very imperfectly preserved vegetable remains alone could occasionally, and very sparingly, be noticed. The Drift, from the Bayou Zoury up to this point, presents the usual character, capping almost all the higher ridges, and frequently ftbrinig their body also. Its only peculiarity in this region is the frequent occurrence of very coarse, white sand, resembling Liverpool salt-its material being chalcedony and quartzite. THE TOREAU /REGION. Beyond the Toreau, toward Sabinetown, the long-leaved Pine disappears, being replaced by the short-leaved Pine and a va:ur'iety of upland oaks-among them the White Oak. The chan ge of formation is further indicated by the appearance of a heavy, red subsoil, and occasional patches of limy prairie, with vestiges of shells; while in [r 9 ] ravines and in the bluffs of branches, we find the characteristic limestone of the Vicksburg marine Tertiary, alternating with greensand marls containing poorly preserved shells. The ridge soil, of which a specimen was taken, about section 26, township 5 north, range 12 west, is of a dark mouse-color, and moderately heavy to about eight inches depth; then follows a deep orangered, and rather heavy subsoil. The timber near this spot was shortleaved Pine, Hickory, Elm, Ash, Red, Spanish and much White Oak. About a mile fuirther on, there is a denuded hillside, where the drift is exposed, and is peculiarly rich in fossil wood —Palm wood among numerous other species. Not far from this we find in branches, not marl, but brown laminated and blue sandy clay, with fossil leaves pretty well preserved, and closely resembling the materials lying at the foot of the Vicksburg bluff; and similar materials continuedl to be seen at the lower levels up to the edge of the Sabine bottom. On the hills, however, we find, about section 26, township 5 north, range 12 west, and for some miles north and south of that locality, a ledge, twelve or eighteen inches thick, of a dark ferruginous clay rock, cleaving in laminia, about a foot or two below the surface of the ground, which is strewn with ferruginous pebbles of all sizes. Beneath the ledge of rock lies a dark, highly ferruginous, stiff cla.y;this, as well as the rock, contains numerous casts of shells, amongst them Arca Mississippiensis, of Vicksburg. The soil resulting from the disintegration of" these materials, is stated to be very productive of grain crops, and very lasting; it is said to occupy a strip one-half to two miles wide by five to six miles in length, north and south. At soume points the rock strikingly resembles the matrix of the Red Bluff fossils on the C(hicka.sawha;y river; but the abundance of A-rca Mississippiensis, which characterizes it here, seems rather to assign it to the top of the Vicksburg profile. Altogether, the Toeau country possesses no mean attractions in an agricultural point of view. The uplands are of very fair quality. and the numerous valleys may, to a considerable extent, be accounted first-class lands. The country becomes gradually less undulating as we approach the Sabine, and the slope into the bottom is gradual.t The latter is about a mile wide, and its actual character contrasts rather strongly with that usually given it in maps, where it is represented as a broad banld of marsh. In matter of fact, it is rather uncommonly undutlating, and timbered mainly with Oaks mingled with short-leaved Pine, and at some points a good deal of Beech. Nor, accordinog to all the information I could obtain, does it assume a character different from the usual one of streams in the Gulf States, above the latitude of Lake Charles. SABINETO WN. Sabinetown, Texas, is situated on a bluff 150 feet high, falling off steeply into the river. Hence it affords one of the best opportunities M Mississip)i Report, 1860, p. 135. t Ibid, page 142. [ 20 1 for studying the character of the tertiary strata of the central portion of Louisiana, and the detailed section of the bluff; as shown just opposite the town, is too instructive to be omitted here. Profile of the Blzuf at Sabinetown, Texas. NO. ~ MATERIALS AND CHARACTER. I'liEET IFORMATION. 14 Ferruginons sandstone, and conglomerate of pebbles with fragments of silicified wood............................ 6 13 Ferruginous sand, of the usual Drift facies, with two or 18 three ledges of ferruginons sandstone................ —-- 12 Yellow and variegated sand, with clay laminae inter- 6 spersed........1 Gray or brownish laminated clay, with yellow (ochreous) cleavage 25 + cleavage planes, and a few sandy layers............. lo Yellow and variegated sand, with clay bands at intervals - _ W of about twenty inches.30.... —. ——...G dray laninated clay with Selnite, and ferruginous strati- i 1 fication lines at intervals of ten inches. —. —-------- 8 Greenish ferruginonus sand with clay lainine- ------—. 3 7 Ferruginous, concretionary sandstone, porous, fossilife- 3 rous... —-------------—. —-—. —--..-..... —----- 6 Solid blue sandy clay.-.-........................... 1 3 5 Brown laminated clay with Misy-....................... 1 Blue fossiliferous limestone, sandy, with Bos.elliaria velata 2 3 Greenish sand, alternating with clay lamine.. ——.. —-- 6 2 1 Blue calcareous sandstone, fossiliferous....... 2... 2 1 | Greenish sand, as far as visible.... —. —. —-.. —-- -. 2 The general dip of the strata is decidedly southward, but its amount can scarcely be measured on the rough surface of the ledges. It may be as much as two or three degrees. The stratification is frequently quite irregular, partly owing to disposition in basin shape, and partly to dislocations and subsidences, the limits of which are usually marked by laminated ferruginous veins, with kDots and curves. At the foot of the bluff, where at high stages of water it is difficult to find a passage, is lined with blocks of dark colored rock, tumbled from above. These are mostly derived from No. 7 of the section-a porous, concretionary, ferruginous sandstone, with casts of fossils, now unrecognizable. There are, besides, blocks of hard limy sandstone or sandy limestone, derived from Nos. 2 and 4. The former is generally poor in fossils, the latter in places very rich, and the fossils well preserved, but very difficult to, detach from the rock. Among them, a small variety of Rostellaria velata is the only fossil usually characterizing the Jackson group. But this, at the time of my visit, I failed to identify, and was inclined to consider the fauna found here more nearly related to the Vicksburg than to the Jackson group. But at a subsequent visit, Prof. Hopkins found on a tributary entering the Sabinejust above the ferry, a bed of shells bearing most distinctly the Jackson character. While it is thus proven that the lower (marine) portion of this profile is of the latter age, the upper (lignitic) part is thereby par I[ 21 ] allelized to the lower division of the aicksburg bluff, to which it bears a close lithological resemblance. And if we define the area actually underlaid here by the Vicksburg marine rocks proper, we cannot assign to it, on an average, a width greater than about three miles in a northwest and southeast direction. At another point on the tributary mentioned above, I found stratum No. 4 of the preceding profile, very poor in fossils, but, exhibiting rounded concretionary masses of sandy limestone, traversed by veins of calcareots spar. They are undistinguishable from those brought up from the oil bearing stratum of the Calcasieu Sulphur Well;* and a comparative analysis of the two rocks, while showing a very close correspondence with each other, and the other tertiary limestones examined, exhibits the wide difference in composition from the crystalline limestone associated with the sulphur; that, in its turn, is chemically identified with the other cretaceous limestones of the State.l' A bed of lignite, said to be of excellent quality and at least ten feet thick, crosses the river about two miles north of Sabinetown, causing rapids. This shows the marine strata to be of little thickness, and probably incontinuous within small areas. SABINE PARISH. Leaving Sabinetown. on the Manny road, we ascend into the hilly country immediately after leaving the river, the bottom being on the Texas side. We meet again the stiff, glaringly red subsoil and (drift outcrops of rather a clayey character, on the hillsides. The vegetation is less luxuriant than that seen further south, on the Vicksburg territory-there is more Pine, Post Oak and Black-jack, and less White Oak, Gum, Ash, etc. At various points between Sabinetown and Manny, we find in the bluffs of streams outcrops of more or less lignitiferous clays and sands, associated quite frequently with large concretionary masses of a very hard and fine-grained, oftentimes cherty, but mostly non-fossiliferous limestone. On Bayou San Jos6, limited beds of lignite occur at several points; while oln the heads of Bayou, Negrete, e. g. near I)utton's tannery, and in the neighborhood of Manny itself, lime of a good quality was burned. A very detailed survey alone could map out the numerous isolated points of occurrence of the several materials, which have evidently been formed in shallow estuaries, lagoons and marshes, frequently interchanging their places in the course of time, It had been my intention to proceed from Manny to Natchitoches; but as it became obvious tbat the party was traveling in the direction of the strike of the formation, while the objects of the expedition required that it should be crossed as frequently as possible, we faced to the left about in the direction of Pleasant Hill and Mansfield. About two and a half miles north of Manny, the long-leaved Pine appears again on the ridges, mingling with the short-leaved species, * See mly " Preliminary Report"'7 page 12. t See analyses, below. [ 22 j and Oaks; which are thickly hung with Long Moss. Patches of the latter are said to extend for some distance along the crest of the dividing ridge between RPed and Sabine rivers. Unfortunately, the road traveled runs almost altogether on this level ridge, rendering observations of the geological formations difficult. The deep red subsoil continues to be seen; the soil is in some places quite poor, bearing only Pine with small Black-jack and Post Oak; but mostly it bears a good growth of other Oaks, and is of ~fair quality. According to information given by Mr. Isaac Rains, at the Armstrong settlement (section 35, township 9 north, range 11 west), outcrops of limestone exist two uiles south of that point, and again fifteen miles in an east by north direction, on the Natchitoches road. In the neighborhood itself, lignitic clays alnd sands, as well as lignite beds, are found in the wells and water courses. At one point, a lignite bed was found four feet in thickness; in other wells, two strata of two feet each, etc., at depths varying irom thirty-five to fifty feet, according to the surface location. Gypsum occurs in rosettes in the laminated clay, and often contaminates the water of wells passing beyond the drift, which covers the ridges, here as elsewhere, to a variable, depth. Its februginous sandstone is common on the hills, as is also silieified wood. A good deal of iron ore, also, is found in the upland soils at some points-the surface soil is generally light, but the subsoil heavy, being derived from the tertiary clays. Hence the land, though productive and lasting, is a good deal influenced by the seasons. On the lower slopes and at the foot of the ridges, springs are abundant, being shed by the cla,y strata after percolating through the drift; hence the streams are kept flowing throughout the year. It appears that the " soda" made by Governor Allen during the war, was obtained by digging pits in " salty spots" in the Sabine flat (about two miles from TMyrick's Ferry), a nd evaporating the water thus collected; or else by leaching the surface earth. Common salt, also, was made at other spots in the same manner. DOLET HILLS-IRON ORES. The sanme general character of soil and country continues up to Pleasant Hill; outcrops of lignitic clay are reported as occurring all along in the streams at the foot of the ridge, but no limestone. At Pleasant Hill (whose location in a gently undulating and productive upland region justifies its name), the party (desceelded friom the main ridge, making a detour through the hilly country on the Red River side (part of the "'Dolet Hilis"), in order t-o gtain access to the outcropping strata in the ravines. Tfi)ese were found to be ligoitic clays aud sands of variable character. The hills are finely timbered with tall Pines (short-leaved), Oakis and Elm. At somen points there is for a mile or so a very gravelly soil, the gravel being exclusi+vely of a concretionary ferruginous imaterial; and on the brows, as well as somutimnes onl the top of the ridcges, there crops out large ferruginous nodules; partly of [ 23 1 ferruginous sandstone, partly genuine geodes and concretionary masses of brown hematite. They chiefly occur where the stiff, red subsoil underlies, which is itself filled with ferruginous gravel, sometimes of large size. In washes on the hillsides, clayey strata of the Drift age are shown underlying; in the beds of streams we sometimes find wlat appear to be older strata, but in fact are mere conglomerates of ferruginous gravel and clay, consolidated. Another patch of ferruginous gravel occurs between six and seven miles from Mansfield. The soil is clayey, about five inches deep, bearing rather a poor growth of Pine, Post and Spanish Oaks, with some ]Hickory. The subsoil is of a bright orange tint, full of ferruginous gravel; and on the brow of the hill ferruginous nodules crop out about twelve inches under ground. An analysis of a fair average specimen of the ferruginous gravel occurring near Pleasant Hill, gave the following result: Peroxid of Iron.'....... 57.44 Insoll)le matter (Sand).. 35.19 Water and Alunmina l.... 7.37 100.00 Doubtless Iron could be profitably imannfietured here by sorting the ore somnewhat; and the erection of an iron furnace in this region was contetmplated by Juldge Robertson, of New, Orleans, during the war. Lignite, also, is reported as occurring rather abundantly in this region; ione locality being eight miles north of Pleasant Hill. shallow wells (fifteen to eighteen feet deep) in this region have good water, as they remain within the Drift materials. But where the gray lignitic strata are reached, the water is hard (from Gypsum) and sometines fetid. Springs, however, are quite abundant, and the streams flow rapidly and cheerily. MANSFIELD. At Mansfield (where the party was most kindly taken care of by Dr. It. F. Gibbs), there is a highly interesting outcrop in a (leep ravine just west of the town, which is situated on a broad, level ridge, falling off rather steeply to the westward. This outcrop differs from all seen heretofore in the lignitic formations of the Southwest, in exhibiting a stratum of liamestone of fresh-water origin; and in this regard resembles strikingly the interior basins of the Far West. Profile at Mansfield. NO. MATE HiALS. FEET.' Indurate, clayey sand (orT hard-pan ") of the Drift age.. 15 3 Clay and Sa-d, gray, interstratifie.... (6 2 Ilpure, laliinate(l limlestolle, with leaves.2..-..... --—. 2 Stratified, gray clayey sand, and gray or whitish lai-nin1 ated clay, interstratified. One clay stratum six feet 30 tlhick, the rest a few inches..-.-. —-.. —-------------- [ 24 1 The limestone No. 2, so far as seen, is void of shells, but in its lower portions especially, which are laminated, there is an abundance of lignitized impressions of stems and leaves-mostly fragments, and irrecognizable. Its upper portion is the purest, yet scarcely so as to fit it for lime-burning, save for agricultural purposes. This stratum crops out on many hills around Mansfield, especially northward. Dr. Gibbs informed me that it extends at least eight or ten miles on the Shreveport road, and perhaps to that place.* On a ridge north of the town, at a lower level, apparently, than the limestone, fragments of a ferruginous shale lying on the slope, exhibit abundant and very perfect impressions of leaves. It is an interesting fact that Hoplins also found a leaf-bearing stratum associated with the limestone at Shreveport. I hope, therefore, that this region will furnish the material for comparison both with the tertiary flora of Mississippi, and with that of the interior basins. It seems that lignitic strata crop out on both sides of the dividing ridge from Pleasant Hill to Mansfield, and towards Shreveport. The bluff on the Sabine at Logansport, according to all accounts, is similar to the profile just given. A bed of lignite exists a few miles southwest of Mansfield, and several others in the Dolet Hills, northeast of Mansfield; also at Granning's Ferry, on the Bayou Pierre. Finding the time to be getting short, the party here determined to cross Bled River, so as to examine the salines of North Louisiana, and thence re-cross the marine formations, on the route to Harrisonburg DOLET HILLS -GRANNINGGS FEIRRY. On the wav from Mansfield to Granning's Ferry, the country differs little from that seen between Mansfield and Pleasant Hill; becoming more broken as we approach the river, and the body of the hills consisting of lignitic clays and clayey-sands, with some Drift with ferruginous sandstone capping them. The deep red subsoil appears frequently, but is often covered by a pale yellow loam, which is considered the poorest soil hereabouts. A specimen of the heavy red subsoil was taken on a hillside about two miles from the ferry. The surface soil is only a few inches deep, a little more sandy and grayish; depth at which the subsoil was taken ten inches. Vegetation, a rather indifferent growth of upland oaks. The subsoil, saturated with moisture at 710 Fahr., lost 8.98 per cent. of water at 400~, and thus dried, consisted of: *This is confirmed by Prof. Hopkins, who found the profile at Shreveport very similar to that at Mansfielcl [ 25 Insoluble matter.-..................... --------— v - 71.800 Silica soluble in Na. Co. 3.-.-. —------------------ - -...-..... 7.450 Potash. —---------- ---------- -----—. —-------—. ——.. --— D 0.367 Soda ------------------ --- ------ ------------ 0.008 Lime,.... - -.-.. 0.055 Magnesia ——.. — -----------. --------------—.. 0.449 Br. oxide of Manganese —-- ----------------- ------- 0.056 Sesqui oxide of Iron.................-..-..-......- 8.966 Alumina. -—. —----—..... ------ 7.119 Phosphoric acid.-... "...'-.-0.179 Snlphuric acid.. —--.. ------------------- ----—... —. —. 0.007 Water and Volatile matter......................... — --—..... 4.820 100.786 For so clayey a soil, this one is rather poor in potash, while compar, actively rich in phosphoric acid. The amount of lime is too small by far to render such a soil as this thrifty; and the application of lime to it is at once indicated as an important means of improvement. Being very heavy in cultivation, deep and thorough tillage will be particularly essential. Doubtless, much of the heavy red subsoil mentioned repeatedly, is richer in nutritive ingredients than the one analyzed; none probably is poorer. But I have no doubt that the necessity for applying lime exists in all. judging by the usual vegetation. The lignite bed near Granning's Ferry is on a hillside, not well exposed; from three to four feet thick, and of good quality. Its extent cannot be ascertained without digging or boring. The right bank of the Bayou Pierre at this point is a steep bluff of whitish laminated, almost chalky looking, clay, some ten feet above high water mark. It resists washing considerably, andl this explains the existence of elevated ridges between BayouT Pierre and Red River both above (in the lake) and below this point [the Macdoau HillsJ. Since, a few miles inland, the clay occurs on hill-tops elevated at least 350 feet above the river, this number represents the minimum thickness of the formation in this region. RED RIVER BOTTOM. The banks of most of the bayous exhibit characteristically the reddish tint of the Red River alluvium. Thus Boggy and Grand Bayoas, along which the patrty passed to Grand Bayou Landing, and thence turned down stream to cross at Coushatta Chute. Red River was above its medium stage of water, and hence the observations along its banks were not as satisfactory as could have been desired. Still, the fact that the channel is in a great measure cut into a formation older than the alluvium, became obvious in the course of a few miles. The fresh alluvial deposits bear predominantly the character of a reddish loam, alternating frequently with streaks and sheets of red clay possessing the wavy structure. Sometimes these loamy deposits, from which the lighter class of the bottom soils is derived, would continue down to the water's edge. But more generally, at a depth varying from seven to twelve feet, a different kind of material would appearheavy red or blue clays, or both alternating; with streaks of calcareous 4 !2j 6 concretions often marking the stratification lines, which are not wavy on the small scale. -The visible thickness of such strata frequently exceeds twenty feet; and it was stated by intelligent persons that they continued the satme, or nearly so, to low water's edge, making up an aggregate thickness of thirty-five or forty feet. The:l following profiles will illustrate the condition of thingso Sections of Ped River Banks. FT. J I.6 MILES ABOVE COUSHATTA LANI)'G 11]. 4 MILES ABOVE COUSHATTA. FT. 5' Reddish gray sandy loam. Reddish gray loam. 7 2 j Gray, indurate loamy sand. ti2f red clay. _ _ 3 Loam, like top straituml. Reddish gray loam. 2 Stiff red clay. Stiff red clay. 3 Gray Loam. Yellowish gray loam. 1K Stiff red and bluish clay, with cal10 Red loam, coherent to water's edge. careous concretions; alternating 17 in strata fiom 1 to 3 feet thick. FlT. I: II. 3 MILES ABOVE'COUSI1A'rI'A. IV. a2 T MILES ABOVE COUSHATTA. Fi'T. 8 Recddish and variegated loan and clay-river deposits. i I Stiff red clay. IReddish loam etc. Reddish loamn. 3 1 Stiff red and blue clay. River deposits.: 4 1 Sandy hard-pan, in ledlges, (Gravel conglomerate, basin shaped: coarse above, fine below. t'arther _ 3~ on, pure sand, partly conglom- Stiff brown clay. r P i 1 erated into ferruginous rock. Yellow loamy sand. } a 4 1 Stiff red clay -Brown clay with roots and ] I Blue clay, to water's edge. leaves. J v The red clay occurring in the lower portion of these profiles, is quite similar to that which is now formed by the back-water of the river, and may be seen where the undoubted river deposits are exposed. But the sheets of clay so formed, as might be expected, rarely exceed a few inches in thickness, and show a wtavy surface. Nothing' like the heavy, uniform strata of stiff red and blue clays, which are exhibited in the river banks continuously for miles, are now formed by Red river. The color apart (the blue clay being doubtless derived from the red by a simple process of reduction), these balnks at once recall the profile at Port inHudson; while at some points, they could scarcely be distinguished, color and all, from portions of the profile at C6ote Blanche. Here as there, the lime of the paludal fauna has doubtless been dissolved and formed into concretions by muaceration.*i At one point only were well preserved fossils found, viz: in the gravel conglomerate of section No. 11I (above); they were a Unio and a Paludina. A few smaller land shells (Helix, Helicidna, Pupa), occur in the overlying strata. It thus appears that the valley of Red river, like that of the Missis-, Am. J. Science, Jan. 1869, p. 81; Smiths. Contr. Knowl., No. 248, pp. 11 and 12. L 7 2 sippi, was converted into a swampy estuary at the time of the Champlain depression; the cypress stumps in Profile IV completing the analogy. It is stated that the banks maintain the same aspect up to Shreveport at least; and, as was subsequently ascertained, similar materials underlie the whole of the level lake country bordering on Red river, the color of the clays being, however, mostly blue or gray -a change readily understood. RED RIVER SOILS. There are in this portion of the Red river bottom, four chief varieties of soil, to which my attention was called by Maj. Dickson, a highly intelligent and progressive planter, near Grand Bayou Landing. 1. Fr'ontland Soil.-Near the river and the main bayous, there is a yellowish red or reddish loam soil, light and easily tilled; deep, and very productive. In the "back bottom," farther from the channels, this soil becomes gradually heavier and more difficult to till, and forms 2. Back Bottom Soil.- Also very productive, and, doubtless, more lasting than No. 1. Both obviously alluvial. 3. Bottorm~ Pbrairie Soil. — A black, calcareous soil, fully twelve inches in depth; timber, large Ash, Water Oak, Cottonwood, Hackberry, and Honey Locust. Occurs in patches; very productive-;"a capital soil.7 4. Waxy Soil.-Also in patches-an exceedingly heavy, close, intractable clay, mostly in low ground. It bears a curiously stunted, or rather stationary, growth of Hackberry, Ash, and Elm; trees thirty years old being no larger than we usually see them after three or four; besides these, it bears large Overcup Oaks. It seems to be practically worthless, at least for the present. The last two soils are doubtless derived from the older clay strata; No. 4 from the stiff red and brown, non-calcareous clays, while No. 3 is similar to the "buckshot" prairie soil of the Tensas bottom, and derives from the lighter calcareous clays of the Port Hudson age.* The following analyses give some light on the peculiarities of these soils, and of the materials concerned in their formation: 2Recddish Red Dark ALLUVIAL LOAM. CALCAREOUS CLAY. BOTTOM PRAIRIE. Insoluble Matter - ---- 90.48 3 94.48 65.25 632 78.1 84.71 Sillca, soluble in Na C03- - 4.00 - 7.47 6.53. Potash -....... -—. —---- 0.22 0.46 0.61 Soda -.-. —. -—. —.. 0.01 0.36 0.06 Lime --.... -. 0.292 8.07 0.49 Magnesia.-.- -. 0.59 5.66 1.04 Br. Ox. Manganese.......... 0.38 0.08 0.25 Peroxid of Iron. —-----—.. 1.69 5.98 3.30 Alumina.... —--—.-... 1.41 6.68 4.23 Phosphoric Acid. —--- -—.. 0.22 0.26 0.15 Sulphuric Acid.. —.... 0.04 Trace. 0.01 Carbonic Acid. —---. —----- 3.91 WTater and Vol. Matter. -—. 1.29 5.82 4.92 Totalt.-..... D - 100.55 100.50 99.78 Hygroscopic Moisture. 3.05 8.32: On this sublject, see a paper'On the Geology of the'Miss. Bottom," by E. A. SmitlL, in Proc. Am. Ass'n Adv. Sci., 1871, p. 252. [ 28 j The prominent characteristic of all these materials is the comparatively large amount of lime contained in them; and contrary to all expectation, they are poor in sulphates. The great fertility of Red river lands having been usually ascribed to the gypsum carried down from the great gypsum beds above, this is an important fact. The lime may have been originally dissolved in the shape of gypsum, and decomposed in lransitu into carbonate of lime and soluble alkaline sulphates. It is not often that we find in a deposit or soil yielding over 94 per cent. of insoluble residue, so large an amount of the important nutritive ingredients - potash, phosphoric acid, and lime; the great thriftiners of the alluvial soils of Red river is. thus explained. The back bottom soils (No. 2) probably contain more potash, and may be more lasting than the frontland soils; whose depth and easy tillage, nevertheless, render them very desirable. The black bottom prairie soil closely resembles in composition the "buckshot" soil of Coahomla Co., Miss., analyzed by Dr. Smith (1. c., p. 260). The relatively and absolutely large amount of lime in these soils accounts for their extraordinary thriftiness. THE 3ZBLACK LAKE COUTNTRY. Crossing Red river at Coushatta Landing, where the uplands approach the river pretty closely, the party proceeded on the Vernon road. The red clay subsoil of the country south of the river, soon reappears in the slightly rolling uplands which form a low dividing plateau between Red river and the Grand Bayou of Black Lake. It is timbered with short-leaved Pine, Post, and some Spanish Oaks, and scrubby Black-jack-a poor and whitish soil in the lower portions, where Phlox glaberrima and Candle-berry appear; but pretty good where the Spanish Oaks are large. At the higher points, freestone wells may be had in the Drift materials, whose characteristic ferruginous sandstone is common on the ridges. But in many cases, the lignitic clays and lignite, with flattish, hard, and sometimes fetid water, are struck. Black Lake bayou flows divided into numerous branches separated by swampy fiats, appearing very much as though the lake had reached much farther inland in times not remote. Water, coffee color. Beyond Bayou Castor, the country becomes more hilly, and the hillsides are very pebbly. The pebbles are often cemented into a kind of pudding-stone by brown hematite; but the latter does not appear in mass. KING'S SALT WORKS. The salt works heretofore owned by Mr. King, butI now bly Mr. Wardlaw, are situated on S. 35, T. 15, R. 8 W., close to a rather extensive salt lick in the level homnmock of Bayou Castor, where salt is constantly blooming out on the surface. Here, during the war, a number of pits were dug for salt water, twelve to fifteen feet deep. Fromn most of these only white soil and gravel has been dug, but two [29 1 or three have also furnished a soft, gray, calcareous mass, containing a multitude of small oysters, and to my great surprise, very perfect specimens of Gryphca Pitcheri, and of Exogyra costata, two leading shells of the cretaceous formation. In the bed of Bayou Castor, close by, there is a ledge of soft aluminous limestone, greatly resembling the "rotten" limestone of Mississippi, but void of fossils. A few hundred yards northward of the lick, there is a dug well twenty feet deep, in which a similar rock was struck at five feet, which became harder as the depth increased, and had to be blasted. The rock now lying near the well is a rather hard crystalline limestone, full of debris of shells; a great maDy perfect ones were found in digging; one described to me must have been a Janira! No salt water was obtained in this well. Another well was bored one hundred and thirty-six feet deep, and on penetrating the rock at this depth, salt water rose to within reach of a very crude suction pump — indicating a strong artesian rise. This well has chiefly furnished the brine for boiling, but is quite weak-not, I should think, above the strength of sea-water. Hence the manufacture of salt ceased with the war. About a mile east of the works in a boggy place, there were several detached blocks of white crystalline limestone, similar to that at the dug well. But whether these had been brought here or not, could not be ascertained. From this interesting locality, the first one at which the existence of cretaceous outcrops in Louisiana was recognized, the party proceeded eastward to Rayburn's Salt Works, on Saline Bayou. The country between is quite undulating and in part very sandy, so as to wash very badly. Oaks mingled with the short-leaved Pine form the timber to within seven miles west of Saline Bayou, where the long-leaved Pine sets in. At times the hefavy red clay subsoil appears, and lignitic clays are found in wells; but the ridges are everywhere capped with the Drift materials, whose character, on the whole, predominates. RAYBURN'S LICK. On crossing the Saline, we ascend a high hill into the usual oak and pine country. Six miles from the crossing, on S. 34, T. 15, R. 5 W.t there is an extensive fiat like that at King's, covered with deserted pits and furnaces, built of ferruginous sandstone. As much as eighteen hundred bushels of salt per day have been made here during the war, and it is stated that a single well might have supplied all. The variety of materials taken from these pits is very great. In the chief well, limestone like that at King's was found at twenty feet, It being extremely difficult to ascertain positively the exact succession of strata in the present condition of the pits, I give the profile as obtained on the spot from Rteuben Whitlow, an intelligent wulatto, who worked here duringo the war. [ 30 l Profile of Salt Water Pits at Rayburn's. -NO. | MATERIALS. FEET. Whitish mud of the lick, with ferr. spots, and at base frequently 6 bearing balls of pyrites —---------------------------------- 3 Siliceos gravel, often cemented into a conglomerate by crystallized 67 Grayish or white crystalline limestone, horizontally banded, fragile, 2 often covered with, 5-6 inches crystallized aggregates of calcite, 6 on a dark, banded base of the same ---. I Dense, banded gypsum, pure-_....1 2 No. 1, the gypsum bed, was reached only in the pits of the S. E. side, and the salt water came up from beneath; in the other pits it calne in through crevices in the limestone. The latter resembles that seen at King's, but appeared to be void of fossils; sometimes it is very porous and mostly in irregular lumps, exuding salt. Some of the gypsum is beautifully banded, and is almost alabaster. Fromi Rayburn's Salt Works, now also deserted, the party proceeded to Brushy Valley, where valuable information was obtained from Dr..F. C. Gray, as well as from Mr. Win. N. Parke. LICKS AND PRAIRIIE SPOTS. It appears that, as a rule, lignitic clays and sometimes lignite, are struck in most of the wells in the region; but that isolated patches of calcareous materials are found at several points near; e. g., on Coulee Creek, a few miles above Dr, Gray's, and at or near Rochester, where the soil is a true black prairie, with calcareous concretions, but no shells so far as known to Dr. G., nor any indication of salt. He states, however, that shells were found abundantly at Rayburn's, as well as at King's. 1Mr. Parke states that " prairie spots " exist also on Choctaw Bayou, about ten miles northward of Dr. Gray's; and on Antoine Bayou, near Louisville, Winn Co., as well as on Big Creek. Also, that ferruginized shells, such as were shown me by Dr. Gray at Lake Charles, occur on SS. 7 and 18, T. 15, R. 4 W., and SS. 12 and 13, T. 15, R 3 W. This soft shell rock is found a few feet beneath the surface, in digging wells; is underlaid by 20-25 feet of red, or red and white, clay, beneath which, after penetrating a thin layer of sand, lignitic clay or lignite is struck. These shells are therefore doubtless of tertiary age, and they as well as the "prairie spots7" do not seem to be related to the cretaceous beds of the salt licks* Unfortunately, there was no time for a personal examination of the localities referred to above; and the party proceeded southward to 6 Price's Lick" and Salt Works, on S. 25, T. 13, R. 5 W., or thereabouts. On this route, we pass from the undulating oak uplands with short-leaved pine, into the long-leaved pine wood(s, about five and a}hallf miles S. E. of Dr. Gray's, after crossing Brown7s Creek. The T This supposition has since been confirmed by the researches of Dr. F. V. Hoplkins. [31 ] soil is mostly rather sandy, yet occasionally the red clay subsoil reappears. The dividing ridge itself only is absolutely poor, there being much good oak land on the slopes. The ferruginous sandstone of the Drift is not as abundant here as near Brushy Valley; where (just south of Dr. Gray7's), there are outcropping ledges of some thickness. Available iron ore does not, however, seem to occur in the region. PRICE'S LICK. Price's Lick, which resembles the others in its general character, is of a horseshoe shape, about one-half mile a.cross from edge to edge. On its eastern edge runs Cypress Bayou, a small but brisk stream. The whitish and rather sandy surface of the lick possesses a well pronounced saline flora, and exhibits an. abundance of roundish, distorted calcareous concretions, some as much as eight ounces in weight. The materials thrown from the pits are exclusively gray laminated clay (" soapstone"), of the usual character of the lignitic Tertiary. T'he pits are not very deep, and perhaps the underlying limestone and gypsum had not been reached in them. The brine was stronger here than at either King's or Rayburn's. As at the latter localities, the (now deserted) furnaces here are built of the ferruginous sandstone of tbe Drift, which occurs on the hills, though not as abundantly as near Brushy Valley. Among the rubbish we found rounded concretions of a yellowish green, radially crystalline mineral, weathered on the outside into a pale yellow powder; doubtless Vivia.nite, somewhat altered. DRAKE'S SALT WORKS. From Price's the party next proceeded to Drake's old Salt WVorlks on Saline Bayou, thoen owned by Mr. J. C. Weeks. The licks extend for one and a-half miles along the bayou. At their northern end, on the east bank, a number of artesian wells have been bored; one, a thousand and eleven feet deep, and said to have been sunk in uniform, limestone rock all the way, spouts a constant stream of from eighteen to twenty gallons of salt water per minute. It now runs out four and a half feet above ground, but will rise above thirty-five feet in pipes; the discharge is said to have decreased since first bored. The water of this well contains two per cent. of solid matter, which consists, by subsequent analysis, of Chlorid of Sodium........................................ 93.30 " Magnesium -..... — --... —-................. —.. 1.78 Carbonate and Sulphate of Lime... —--—........................-....... —-. 4.92 100.00 There are seven other wells, all running when cleaned out, but of less depth, and having somewhat stronger brine than the first named. They were bored some thirty years ago for Mr. Drake, and their record is not known. [ 32 1 Htere as elsewhere, many pits were dug during the war, fifteen to eighteen feet deep. All these struck the laminated clay or "soapstone;" but in the rubbish of one I found large fragments of a very crystalline, yellowish limestone, horizontally banded with gray; evidently the same as that at King's and Rayburn's. The lick is overflowed at high water, and was partly so when seen by us. There is a splendid water power here, and a large saw and grist mill, as well as salt. boiling, were carried on during part of the war; when the whole establishment was destroyed by fire. Mr. Weeks states that a mile below this point there is an outcrop of red and gray rock on a hillside facing north. Also, that six miles farther west, a ledge of limestone crops out in the bed of a creek, and there is a cliff (also facing north) of fossiliferous limestone, of which lime has been made. Analyses of these limestones, which axe doubtless of tertiary age, will be given below. Near the northern edge of the lick, there is an alkaline sulphur spring, whose salts were used in lieu of soda, during the war, in cooking. From Drake's the party proceeded, through unchanging, undulating, long-leaved pine forest, towards Winfield, near which place there was reported to be a " limestone cave." THE LIMESTONE HILL NEAR WINFIELD. The locality is on Mr. Matthews' place, S. 19, T. 1N., R. 3 W. A pond about forty yards across, is surrounded by limestone hills and cliffs —real escarpments, fifty to sixty feet above the drainage of the country, and the rock but scantily covered with soil on which, among other plants not usually seen in this region, the red cedar is abundant. The rock is clearly of the same character as that seen at the salines above; it is crystalline, horizontally banded; sometimes pure white and yellow calcite, crumbling like loaf sugar; but mostly grayish with darker stripes, and strikingly like the rock seen near Chicotville, in St. Landry Parish. Being very pure, the rock makes excellent lime; but seems to be totally void of fossils. Were it not too brittle, and fiull of fissures and pores, some portions of it would form a beautifully banded marble. The'"cave" is now a mere crevice in the face of a cliff, and would never have been formidable. There is also a "tower," an isolated limestone cliff, with almost perpendicular sides. It is evident that subsidences and consequent dislocations frequently occur in the mass; and large fragments frequently tumble down. There are a number of slightly mineral springs around; probably merely underdrains of the pond mentioned. CEDAR LICK. No other limestone outcrop is known to occur nearer than those at Drake's. But about seven miles south-east from this limestone hill, there is another salt, lick, called Cedar Lick (from cedars growing 1 33 1 there); it is several acres in extent, and there is on it. a steadily flowing brine spring, of pure taste and considerable strength. It can hardly be doubted that here, also, the cretaceous rock underlies at a moderate depth. HOMEWARD BOUND. ]Having now accomplished the round of the salines, the party was compelled, for want of time, to proceed with all possible dispatch towards Harrisonburg, and make such observations only as happened to be practicable under the circumstances; the route having been selected with a view to re-crossing the formations, knowing Harrisonburg to be located on the Grand Gulf rocks. No outcrops of the marine Tertiary, however, were found until the territory of the Vicksburg group was reached, which presented features altogether similar to those observed after crossing the Toreau, in Sabine Parish (ste above). -For about seven miles south-east of Winfield, the long-leaved Pine continues to prevail on the dividing ridge (between Dugdemona and Bear Creek); Oaks mingled with short-leaved Pine occupy the slopes, while Beech, heretofore very abundant in the bottoms, almost disappears. Beyond the point mentioned, a growth of White Oak and Sweet Gum appears on the hills, with a heavy red subsoil —precisely as is the case between Sabinetown and the Torean, just north of the Vicksburg rocks. But there was no time to search for outcrops. Subsequently, Prof. Hopkins has found in this region, as well as farther north, a number of patches of the lower marine Tertiary (of the Jackson age). We could only hear of lignitic clays. RE-CROSSING THE VYICKSBURG ROCKS. TJpon reaching the Natchitoches and Harrisonburg road, which we followed thereafter (about the middle of T. 10, R. 2 W.), there commences a level tract of cotuntry much resembling that above and around Black Lake and its bayous, described above; viz: Post Oak and Pine fiats, with a "' hog-wallow" soil of heavy gray clay. This feature becomes more pronounced as we advance eastward; and about seven miles (west) from Little River ferry, we find outcrops of whitish, heavy, concretionary clay marl with Orbitoides Mantelli, Pecten Pou.lsoni and Ostrea Vicksburgensis, the leading fossils of the Vicksburg group. Of this clay there are about five feet, and it is underlaid by a stratum of hard, concretionary limestone. Shortly after, we reach a prairie dotted with thickets of Crab Apple and Red Haw, which is about two miles long, north and south, by one and a-half mile east and west; a fine, but ili-drained soil. Farther on, we find a dividing plateau covered with long-leaved Pile, skirting the bottoms of Dugdemona and Little River; which are timbered with AWater Oak and other growth belonging to second rather than first bottoms; though traversed abundantly by Cypress sloug ls. 5 [34 1 We were informed that about eight miles below, just below the mouth of Fishing Creek, there is a bluff, about one hundred feet high above low water-the rock which forms it being so soft that people cut their names into it. This I presume to be Grand Gulf claystone. CATAHOULA PARISH. About two and a-half miles east of Gilmore's ferry we find on the slope of a hill, an outcrop of yellowish Vicksburg limestone; then on top of the hill, Grand Gulf sandstone, with underlying gray clays. This is the dividing ridge between Little River and Bayou Funne Louis, and the outcrops continue for a few miles; when, on descending the eastward slope, we again find outcrops of Vicksburg limestone. Thus each ridge appears to form a "nose" of Grand Gulf rocks projecting northward into the Vicksburg territory; as is so commonly the case in Mississippi. The higher ridges are frequently capped with a mamillary mass of the red sand and ferruginous sandstone of the Drift. Hence to within six to eight miles of lHarrisonburg, there is an abundance of outcrops of the Grand Gulf sand-and claystones, and associated clays, both on the hills and in the creeks; the long-leaved Pine being frequently of a stunted growth, where the latter very barren material forms the soil. Occasionally a strip of white oak land intervenes; and at the point mentioned, there commences a tract of yellow loam soil, at first very sandy, and timbered with long-leaved Pine, which in time is replaced by the short-leavedl species, mingled with Oaks; the ridges being exceedingly sharp and narrow. Toward the north we occasionally catch a glimpse of the level prairie country of the Vicksburg group, lying at the foot of the Grand Gulf hills, and probably influencing the alternations observed in the vegetation of the lower ridges, and valleys. Rock Creek, a branch of Burseley Creek which empties into Catahoula Lake, is crossed on ledges of Grand Gulf rock; and on the eastern bank there are extensive exposures of the white clays that overlie. Near the base is a twelve inch layer of strongly lignitic clay, with traces of vegetable impressions-the first instance of the kind seen by me in Louisiana, where this formation appears to be even more hopelessly barren of fossils than is the case in Mississippi. As we approach Harrisonburg, the Drift on the hills becomes more and more pebbly, and the last slope, about three miles from town, is completely covered with shingle of the usual character, as seen opposite, on the Mississippi bluff. IHARRISONKBURG. Outcrops of sand and claystones still continue up to the town itself; which lies on a terrace above the level of high water, on the bank:of the Washita; and at the foot of a hill whose slopes are white with outcrops of the clays, claystones, and sandstones of the Grand [35 ] Gulf age. The subjoined section* was observed by Dr. Walker, after we parted company. Profile at Ilarrisonburg. NO. - MATERIALS. FEET. 11 I Drift sand with much shingle.............". 1 10 —20 10 Sandstone with yellow streaks, soft............- ---......... 1~ 9 j Bluish siliceous clay. ——..-.. —- ----. --—.. —---. I 3 8 W1 hite, fine-grained, sharp sandstone. —.. —--. —-. —- - 3-6 7 Clayey sand, with irregular masses of sandstone. —. - - --. - 10 6. Hard gray sandstone, cherty.. —... —-........................... I 4 5 Brown sandy clay....... -..............,,,................ 6 4 ] Greenish sandy clay..-.........................................., 3 3} Sand and clay, laminated............................. —------- 3 2 1 Loose sandstone, or sendi-indurate sand.................-..... 4 I Lignitic clay...................................... Talus, still above the town level.... -.SICILY ISLAND; THE LOESS. The last exploit of the party was an examination of the southern part of Sicily Island, under difficulties; the first being to paddle up the river, which was high, in a canoe manned chiefly by raw hands. This examination was of especial interest to me, on account of specimens of limestone having been collected there by Messrs. lhalliday and Coningsworth, fellows of the New Orleans Academy; and in this rock I hoped to find the thus far vainly sought fauna of the Grand Gulf group. Sicily Island (which is cut off from the mainland by. the Washita, and from the bottom by Deer Creek and bayous Magon and Louis) is in part quite hilly; like the mainland opposite, its hills are formed by Grand Gulf rocks, mainly a rather soft, tawny sandstone, which crops out on all the ridges. At one point, not far from Mr. Kendrick's place, a cut in the hillside reveals a stiratum of bluish calcareous clay, the counterpart of that forming the Anacoco prairie soil, and likewise occurring at Grand Gulf and on Pearl river, in Mississippi. An analysis of this marl will be found below; it has doubtless contributed towards rendering the talus of these hills so remarkably fertile; but shows no trace of limestone. After a long search, we finally succeeded in finding the rock sought for, and were severely disappointed. Perched on a terrace of the common Grand Gulf sandstone, and forming the summit of a high hill, was a knoll about eighteen feet high; whose lowest portion showed Drift gravel and sand, while the uppermost five or six feet consisted of gray silt containing gnarledhard concretions of carbonate of lime, often cellular, and (very rarely) containing casts of Helices. Similar knolls The details of this section do not agree very closely with those given by Hopkins; probably both are correct, but taken at different points of the ridge. Such discrepancies within short distances are very common in the Grand Gull groaup. [36j exist at other points in the island, always capping the highest summits; they are obviously outliers, or rather, remnants of the Bluff or Loess formation, whose main body has doubtless been cut away by the mighty ancestor of the Mississippi, during the last period of elevation; leaving on the eastern bank, however, a strip of about fifteen miles average width-to-wit: the "Cane Hills"7 of Mississippi and East Louisiana. Although without any bearing on the problem which it bad been my special desire to elucidate, viz: that of the precise place of the Grand Gulf rocks in the tertiary series: these outliers are of considerable interest, because they show unequivocally the hypsometrical relation existing between the Loess and the older deposits occupying the level portion of Sicily Island, and the Tensas bottom. Returning about midnight to Harrisonburg, the party next day broke up, after a ride of nearly six hundred miles, in the course of twenty-seven days. Leaving my companions to take a boat at Hlarrisonburg for New Orleans, I myself traversed the bottom on horseback, to Waterproof on the Mississippi, whence I took a boat to Vicksburg. THE TENSAS BOTTOM. My route lay across Sicily Island, partly over the neighborhood explored the day before. Crossing the Washita and Bayou Louis, the road passes through the hilly portion of Sicily Island for about five miles, then turns off south-eastward into a level country, not at all swampy, above high water, and possessing rather the character of a hommock or second bottom. The soil is excellent, the subsoil a brown loam; and on the shore of Lake Louis, there is a bluff some twenty feet high, washed into cliffs like the indurate yellow silts of the Port Hudson bluff; which it greatly resembles and to which, probably, it corresponds geologically.* Large cotton plantations cover almost the whole of this region. The waters of Lake Louis covered the low bottom lying opposite, to the depth of several feet; and it was with some difficulty that, with the aid of the blind ferryman at Mr. W. S. Peck's ferry, I succeeded in reaching dry ground, and the magnificent plantations on Tiger Bayou, through which I made my way to Kirk's ferry, on the Tensas. The soil here, of the " buckshot" character, is very much like the "'bottom prairie" of Red river; it frequently contains calcareous concretions; and its natural vegetation (1-Ioney Locust, Crab Apple, Plum, etc.), is of the prairie character. At several points in the bayous, and on the Tensas river itself, it reaches to the waiter's edge with little change, being, of course, totally distinct from the modern river deposits, and too uniform and widely spread to be ascribed to any modern cypress swamps. It is, doubtless, the counterpart of the lower portion of the Port Hudson Bluff.t * Am. J. Sci., Jan., 1869, p. 79; strata Nos. 3? and 5. Ibid., Oct., 1872, p. 268 and f. Smiths. Conatr. Knowl., 24:, p. 23. t Ibid. [37 ] Having, with considerable difficulty, crossed the Tensas after sunset, the rest of my ride along Choctaw Bayou to Mr. Jno. F. Goodrich's, was by moonlight, and observations not in order. On the following morning I reached Waterproof at 10 A.M., my observations on the route having only served to con-firm those of yesterday regarding the profuse fertility of the Tensas country, and the non-alluvial origin of its best soils. I found 4 Waterproof " to have proved untrue to its name, and to be fast retiring behind the levee. And here terminated my personal observations. NORTH CATAHOULA. In the meantime, Dr. Walker made use of two days during which he should have to wait for a boat, for a supplementary reconnoisance up the river from Harrisonburg, in accordance with my request, with a view to the determination of the northern limit of the Grand Gulf rocks. I give his observations in his own words: "44June 19th.-Startedt p the Columbia road, finding frequent outcrops of Grand Gulf sandstone. A short distance beyond the twelve mile post (which it seemed to me, considering the crookedness of the road, should have been more nearly the twentieth), I found in a branch bottom an outcrop of loose sandstone underlaid by fifteen to twenty-six inches of lignitic clay. Concluding that I must be near the limestone, I observed closely for the next two miles, when I found an outcrop crossing the road; it was yellow concretionary limestone, such as that seen on Bayou Funne Louis. A hundred yards farther on was an outcrop of blue fossiliferous limestone. Stopped for the night. 20th.-Went on two miles farther (i. e., to sixteen miles) with Mr Harrellson, who showed me more limestone outcrops, of which I took specilnens. The first are about ten feet above the bed of Sugar Creek (so called from Sugar Maple growing on its banks), and the last were near the top of a hill, as we went on. We then turned southwest, striking the creek two miles above, but at a level not much different from that near the first outcrops. Here I saw a bed of lignite, of which two feet were visible in the bed of the creek, and disappearing under water. Half a mile farther south, on top of a high hill, I found the Grand Gulf sandstone. Two miles to southward of this locality are the " Chalk Hills," of which we had repeatedly heard heretofore. The first outcrop exhibited a stratum of grayish, compact claystone, turning white by exposure; it lies on top of a high hill, beneath eight to ten ftet of loose white sand with concretionary ferruginous gravel; it was underlaid by tell to twelve feet of common, coarser claystone. Farther southwest, this 6' chalk" appeared lower in each successive outcrop, and overlaid by sandstone resembling lNo. 4 of the Harrisonburg profile; and finally disappeared. The day being far spent-, I set out on my return, reaching Harrisonburg jest before nightfall. Got everything ready for the boat, which came along at daylight on the 21st; so that I reached home safely on the 22d." l 38] Dr. Walker's observations fixed most satisfactorily the northern limit of the Grand Gulf rocks, showing the phenomena on the Washita to be substantially the same as on the Toreau and Funne Louis; and also, that the ridge of Grand Gulf rocks, at whose northern foot lie the Vicksburg prairies, traverses the State from the Washita to the Sabine, forming the prominent topographical feature of Northern Louisiana. The 4 chalk," which does not make a mark on a board, is simply a pure siliceous claystone, as shown by a qualitative analysis made by Mr. Loughridge. LIGNITES. As regards the lignite, I subjoin the determinations of ash (made by the same), both of the Sugar Creek lignite, and that from Granning's Ferry on the Bayou Pierre. Ash Determinations of Lignites. Sugar Creek, Cat;ahoula Parish.-............ -................. -15.12 per cent. Grannig;'s Ferry, DeSoto Parish.......................... 10.63 " " These are about average percentages, and if the beds are sufficiently extensive, they will doubtless prove valuable. The clay marl of the Grand Gulf age, occurring near Hendricks' house on Sicily Island (see above) showed the following composition: Clay, etc..................................................... 94.19 Carbonate of Lime.................................................. ----- 5.81 100.00 Similar materials occurring in Mississippi contain from 0.7 to 1.2 per cent. of potash. But the large amount of inert matter would render their use at any great distance from the point of occurrence too expensive. The marl forming the soil of the Anacoco prairie, is doubtless of a similar composition. So far as at present known, the minarls of Louisiana are far inferior both in quality, quantity, and variety, to those of Mississippi; yet even thus they will doubtless serve important uses in soil improvement. RECAPITULATION. The general results of the expedition having already received ~mention and discussion in a previous publication, I: shall only recapitulate them in so far as they are not sufficiently set forth in the preceding record, or have received additional light from subsequent researches. I premise that the direction of my researches in Louisiana was measurably governed by the probable supposition, that the geological conformation of Louisian-a, lying west of the main axis of the Mississippi valley, must be more or less accurately the reflected image of that of the States of Mississippi and Alabama, east of the same. [ 39 The route was, therefore, so chosen as to cross the trend of the formations as often as possible. This leading supposition was, on the whole, fully verified, with such modifications as the difference of geogralhical position with reference to the continental interior might have lead to anticipate. Two special problems, however, to which analogy could furnish no clue, presented themselves at the outset, viz: that of the age of the salt deposit of Petite Anse, and that of the great sulphur bed of Calcasieu. The former I had found it impossible to solve by an examination of Petite Anse and its sister islands;* while the interpretation of the strata penetrated in the Calcasieu bores, was equally precarious, unless based upon an investigation of the formations of the interior. At the same time, these data were invaluable as starting points for comparison. As such, I insert here, once more, the Calcasieu profiles, as obtained by me on the spot, from the statements of the well-borer (Mr. Munn), and verified as well as rectified by comparison with the pile of borings at the mouth of the wells. Profile of Artesian Wells, West Fork of Calcasieu river. KIIRKIMAN'S WELL. LOUISIANA OIL CO.'S WELL. Formations Thick- ThickDepth ness. Materials. Depth ness. Materials. Feet. Feet. Feet. Feet. Blue and yellow clay, Blue clay,sometimes with: It with some sand strata. 160 layers of sand soaked ~ o with petroleum. 354 160 Loose sand and gravel,,, 1.38 to 153 ft. very peb-; 2~ 173 bly; 153 to 173 ft. finer ~ material. a 333,,'., Gray laminated clay 343 10 (" soapstone "). Sand with..' clay Blue,sandy,nodular line- Z v 96 lamiean,',7'36 feet. 40 stone, with marine shells,: Sand o and gravel, 56 ft. 383 petroleum and gas. Soft, white, crystalline,,60 crumbling limnestone; 450.. —.. Sandy pipeclay, 4 feet. 443 tube driven throu ghi 100 Pure crystalline sulphur. 543 147 About - sulphur. 5 ft. sulphur bed at 650 ft. 690 10-15 " " 680" c Pure gypsum. DIense,gra540 nular,and coarsely crystalline, grayish or white Am. J. Science, Jan., 1869, p. 83. [ 40- The general correctness of thee second profile bhas been confirmed by additional borings made since, by the Calcasieu Sulphur Mining Co., the only material lifference reported by Mr. Granet being the fact that the sulphur is always mixed with a variable but small proportion of limestone or carbonate of lime, which makes it probable that some of the rock strata found alternating with the sulphur beneath the great sulphur beds may also be limestone, instead of gypsum or plaster rock. As regards the higher strata, the only difference noticed was the absence of the " soapstone" or laminated clay stratum —not a matter or surprise in a locality in which, as the above profiles show, there had been extensive denudations before the deposition of the quaternary strata began. My conjecture that the petroleutn originated exclusively in the nodular limestone stratum, and that no mnore of it was found after reaching the white crystalline limestone, was also confirmed by the new bore. My interpretation of the formations as given in the above diagram, has but received additional confirmation from later researches, both of Prof. Hopkins and myself; except only in so far as the nodular limestone at Sabinetown, which I identified with the petroleum-bearing eock of Calcasieu, and conjectured to belong to the Vicksburg group of the Tertiary, has since been shown by Hkopkins to belong to the Jackson group of the same formation. Of the identity of the Drift or Orange Sand, and the Port Hudson group, respectively, there can be no reasonable doubt. My conclusions were based, first, upon the known southward dip of the formations in Mississippi and Louisiana, which would cause those found far below the surface near the coast, to crop out in the northern part of the State. Secondly, upon lithological resemblance. Thirdly, upon reasoning by exclusion. The southward dip had not, it is true, been directly observed; but the general conformation of the Mexican Gulf border admits of no other arrangement, aside from local disturbances. As to lithological resemblance, it would not be a cogent argument where a great diversity of formations might be suspected, But this was not the case here; and I had, moreover, assured myself of' the renarkable uniformiuy with which the general character of the several subdivisions of the cretaceous and tertiary formations are maintaine d over large areas. The Vicksburg limestones and the Grand Gulf clays of the Sabine were undistinguishable from those of the Chicasawhay and Pascagoula, respectively. There was, therefore, good reason to expect that the rocks penetrated in the Calcasieu bores, would be identifiable at their outcrops farther north, even without the aid of fossils-none in a recognizable condition having been brought up by the augur. The two limestones of the Calcasieu well differ widely from one another. The nodular, petroleum-bearing, sandy rock calls to mind at once the;' nigger-heads" of the Mississippi Tertiary, with its lignitoaiphaltic affinities; while the white, crysttalline, brittle limestone beneath has no analogue in the Tertiary, but recalls the uppermost [ 41 J crystalline limestone of the Ripley group of the Cretaceous in North Mississippi. The great gypsum bed of Calcasieu could not fail to suggest some connection with the great gypsum formation of the upper Red river; and likewise admonished one at once of the usual and almost necessary correlation between gypsum and rock salt, whereof an unusually large and pure mass appeared on the same coast, /at Petite Anse. Such were the ideas suggested to me by a consideration of the Calcasieu profiles. The rocks of the Grand Gulf age should have appeared in these profiles directly beneath the Drift materials. But nothing had been found resembling them in the least; and since of all the tertiary groups, this one is the most persistently uniform in its lithological character, its absence might be taken as proven-it having, doubtless, been removed through the agency of the drift currents. The Vicksburg rocks would come next; and to some of these the nodular limestone of (Jalcasieu bears considerable resemblance; while in Mississippi at least, the Jackson group exhibits no corresponding materials. But on reaching the Vicksburg rocks after crossing the Toreau on the way to Sabinetown (see above), I found them to be altogether unlike the Calcasieu rock, while exactly like the Vicksburg limestone on the Alabama line. At Sabinetown, however, the exact counterpart of the petroleum-bearing, sandy, nodular limestone of Calcasieu, traversed by veins of calcareous spar, was exhibited in the bluffs; and in the apparent absence of characteristic fossils of either group, and the utter dissimilarity from the Jackson rocks of Mississippi, I thought it most probable that these rocks also, represented the Vicksburg age. That this was proved to be erroneous by Prof: Hopkins, I have already stated. The fossils collected by him show that not only the Sabinetown bluff, but the whole of the Tertiary of North Louisiana, at best up to within twenty miles from the Arkansas line, are the equivalents of the Jackson strata of Mississippi; that throughout the lignitic area passed over by me, there exist outliers of marine limestone with Jackson fossils; and that ancient beaches of such rocks seem, as a rule, to occur near the salines of North Louisiana. Not having, himself, found any cretaceous fossils at the latter localities, he was inclined to consider these, themselves, as originating in the tertiary strata. He, of course, yielded to the palaeontological evidence I had to present in the shape of cretaceous fossils fromn Rlybarans Lick, as I did to that he brought from Sabinetown. Bat, in order to show, as conclusively as possible, the lithological correspondence of the rocks from the several localities, I have had recourse to chemical and microscopic analysis, which has fully borne out my views, so far as it goes. I give below the comparative analysis of tertiary and cretaceous limestones made by Mr. Longhridge; remarking that Nos. 3 and 4, which I had not examined in loco, were by me supposed to be of cretaceous age, and so laid down on my first geological map of Louisiana, presented before the American Association for the Advancement of Science, at Chicago, in August, 1869. But an examination of 6 [ 42] specimens subsequently sent me by Mr. J. C. Weeks, showed the great resemblance of these specimens to the Calcasieu pretroleum rock; and analysis fully confirmed the impression. It will be seen that they differ materially from the cretaceous materials, while agreeing closely with those of the Tertiary. Analysis of Louisiana Limestones. Insoluble M. Magnesia. 1. Nodular, Sandy Limestone (Petroleum-bearing), Calcasieu 59-80 j2. " " " Sabinetown. -................ 53.34 3. Gray " " Saline Bayou, near Drake's... 6031 6-32 4. Black " " " " "... 33.18 6.07,5. Slaty Lignitic " Mansfield.. —--—.. -- 32.34 6.07 ( 6. White Crystalline " (Sulphur-bearing), Calcasieu. 0.12 7. Gray " " Chicotville 1.98 0.18 E 8. L' " " Rayburn's Lickl....... 0.03 o 9. " Winfield.................... 0.53 These results speak for themselves. The difference between the most impure cretaceous rock and the purest of the tertiary, is still very wide, and holds good, apparently, equally in respect to insoluble impurities, and magnesia. Such uniformity of composition over wide areas, in specimens taken altogether at random, cannot be accidental; the more as the analytical evidence is equally confirmed by lithological and microscopic characters. As regards the latter, an examination of the several residues showed that of the cretaceous limestones to consist of fine, uniformly sharp sand, of colorless or white, saccharoidal quartz, mixed with a small amount of an amorphous greenish powder, which does not adhere to the sand grains. That of the tertiary limestones, on the contrary, showed larger grains, of white and bluish quartz, part angular, part rounded; many of these are incrusted with a greenish mineral; there is no admixture of clay or other loose particles. The identification is therefore as complete as, in the absence of fossils, it can be made. Yet, as regards the Tertiary, there is additional evidence in the fact that on the territory occupied by it in northeastern Texas, there exist numerous asphaltum springs, e. g. in the fork of the Neches andAngelina; near Nacogdoches, and St. Augustine. At other points in the region, gas and indications of oil have been reached by boring. I therefore consider it as morally certain, that the petroleum-bearing rock of the Calcasieu bores belongs to the Tertiary, and is the equivalent of the Sabinetown rocks, and of the petroleum-bearing strata of 43 1 northeastern Texas. That on the contrary, the sulphur-bearing limestone of Calcasieu is the equivalent of the crystalline cretaceous limestones of the North Louisiana salines. That the great gypsum-bed, being in part interstratified with sulphur, is part of the same formation, and is represented by the gypsumr bed at Rayburn's Lick; the geological place of the sulphur being between the limestone and gypsum. And.since the appearance of the crystalline cretaceous limestone near Chicotville, Winfield, and the Salines, sho wv not only the existence of a cretaceous ridge traversing Louisiana from NNW to SSE, and trending directly towards Petite Anse and its sister islands; but when taken in connection with the Calcasieu profiles, prove a west or southwest dip of the same formation: it seems in the highest degree likely that the ordinary and well-known correlation between rock salt and gypsum is here once more exemplified, in the probable connection of the great gypsum bed with the rock salt mass of Petite Anse. In view of the grand scale upon which the conversion of ocean into land occurred towards the close of the cretaceous period, as again exemplified by the magnitude of the gypsum bed: it is moreover probable that the original extent of the rock salt bed was correspondingly great, and that, however it mapy have been encroached upon by solution and erosion during the tertiary and quarternary periods, it will still be found of sufficient thickness and accessibility for exploitation, at numerous points outside of Petite Anse. The saime probabilities hold good, though in a much more restricted sense, of the CalcaSieu sulphur bed. The obvious fact that the Drift currents have encroached heavily upon both deposits, renders the determination of their occurrence in particular localities, a matter of considerable difficulty and delicacy. As regards the economical uses of the limestones analyzed, it would seem that in general those of tertiary age can yield but an inferior quality of lime for any but agricultural purposes. For these, however, they are probably destined to serve as substitutes for the marls whose place they occupy. Nos. 1, 2 and 3 are, of course, too impure for any other purpose, and may, in part, not be available even for that. The purest of the tertiary limestones seems to be that of the Vicksburg group, near I ittle river and Bayou Funne Louis, as well as that which, in the neighborhood of Manny and Fort Jessup, has been successfully used in making lime for building purposes. The cretaceous rocks analyzed will all, of course, furnish a firstclass lime; and the deposits near Chicotville and WVinfield, especially, will hereafter be of importance in this respect, whenever better means of communication shall have been provided. As for the gypsum bed of Calcasieu, the fact that in a sample of borings analyzed by him, Mr. Loughridge found only 0.5 per cent. of impurities, would lead us to expect a deposit of extraordinary purity, [ 44 J capable of furnishing an inexhaustible supply of this material, and adapted to all the uses of which it is capable. I trust that the great shaft now being sunk on the site of the first bore in Calcasieu, will complete the data necessary to establish beyond cavil, the important practical conclusions foreshadowed above.