mm m,.^ %.:i' vlfiiiii' M lliliiili;?-: '*>^ Iff^'-;' SI *i iiiil iiii liii MS: lit;; 1 '^'. K Glass __^_£i3i Book ftu/^^ DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, Director Water-supply Paper 314 SURFACE WATER SUPPLY OF SEWARD PENINSULA, ALASKA By F. F. HENSHAW and G. L. PARKER WITH A SKETCH OF THE OEOGRAPHY AND GEOLOGY By PHILIP S. SMITH AND A DESCRIPTION OF METHODS OF PLACER MINING By ALFRED H. BROOKS WASHINGTON GOVERNMENT PRINTING OFFICE 1913 ^onograe^^ DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, DiRECTOB Water- Sttpply Paper 314 SURFACE WATER SUPPLY ^^^ OF SEWARD PENINSULA, ALASKA . By F. F. HENSHAW and G. L. PARKER w I WITH A SKETCH OF THE GEOGRAPHY AND GEOLOGY By PHILIP S. SMITH AND A DESCRIPTION OF METHODS OF PLACER MINING By ALFRED H. BROOKS WASHINGTON GOVERNMENT PRINTING OFFICE 1913 '^H D. OF D, CONTENTS. Page. Introduction, by Alfred H. Brooks 9 Scope of work 9 Acknowledgments 12 Topography, by Philip S. Smith 13 Climate, by F. F. Henshaw and G. L. Parker 15 General features 15 Temperature.., 16 Precipitation 19 Descriptive geology, by Philip S. Smith 32 Sedimentary rocks 33 Igneous rocks 35 Unconsolidated deposits 37 Gold placers, by Philip S. Smith 38 Nature and origin 38 Residual placers 39 Water-sorted placers 39 Stream plac#rs 40 Beach placers 44 Distribution 48 Developed placers .* 48 Prospective placers 49 Discharge of streams, by F. F. Henshaw and G. L. Parker. 51 Terms used 51 Data given 53 Field methods of measuring stream flow 54 Slope method 54 Weir method 54 Velocity method 55 Office methods of computing and studying discharge and run-off 57 Accuracy and limitations of the data 60 Drainage areas 62 Detailed descriptions and measurements 68 Fish River drainage basin 68 Description 68 Pargon River drainage basin 69 Description 69 Pargon River and Pargon ditch at intake 70 Pargon ditch below McKelvie Creek 71 Pargon ditch below Helen Creek 73 Miscellaneous measurements 76 Niukluk River drainage basin 76 Description 76 American Creek 77 Miscellaneous measurements 78 3 4 CONTENTS. Detailed descriptions and measurements — Continued. Fish River drainage basin — Continued. Niukluk River drainage basin — Continued. Page. Casadepaga River drainage basin 78 Description 78 Casadepaga River below Moonlight Creek 79 Miscellaneous measurements , 80 Ophir Creek drainage basin 81 Description 81 Ophir Creek at Canyon ditch intake 82 Canyon ditch near intake 83 Canyon ditch above claim ' ' No. 10 above " 86 Miscellaneous measurements 87 Solomon River drainage basin 87 Description 87 Solomon River below East Fork 88 Miscellaneous measurements 90 Eldorado River drainage basin 90 Flambeau River drainage basin 91 Nome River drainage basin 91 Description 91 Nome River above Miocene ditch intake 92 Nome River below Miocene ditch intake 95 Natural discharge of Nome River at Miocene ditch intake 96 Nome River below Pioneer ditch intake 97 David Creek at Miocene ditch intake * 101 Hobson Creek at Miocene ditch intake 102 Hobson Creek below Manila Creek 104 Campion ditch at Black Point 105 Miocene ditch system 107 Description 107 Miocene ditch at Black Point 108 Miocene ditch at Clara Creek , Ill Miocene ditch above Hobson Creek 113 Miocene ditch below Hobson Creek 115 Miocene ditch below the flume 118 David Creek ditch opposite Black Point 121 Jett Cieek ditch ■ 123 Grand Central ditch 125 Seward ditch system 126 Description 126 Seward ditch at intake 126 Seward ditch below Hobson branch 129 Seward ditch below Dexter Creek flume ]30 Seward ditch above Newton Gulch 132 Hobson Branch of Seward ditch 134 Pioneer ditch system 135 Description 135 Pioneer ditch at intake 135 Miscellaneous measurements 138 Snake River drainage basin 139 Description 139 Snake River above Glacier Creek 140 CONTEN^TS. 5 Detailed descriptions and measurements— Continued. Page. Penny River drainage basin 141 Description 141 Penny River and Sutton ditch at intake 141 Cripple River drainage basin 143. Description. 143 Cedric ditch above penstock 143 Miscellaneous measurements 145 Sinuk River drainage basin 145 Description 145 Upper Sinuk River at elevation 700 feet 146 Windy Creek at elevation 650 feet 147 North Star Creek at elevation 900 feet 148 Miscellaneous measurements 149 Tributaries of Imuruk Basin 150 Fall, Pond, and Glacier creeks and Snow Gulch 150 Cobblestone River 151 Grand Central River drainage basin 151 Description 151 West Fork of Grand Central River at pipe intake 153 West Fork of Grand Central River at ditch intake 155 West Fork of Grand Central River at the forks 156 Grand Central River below the forks 158 Grand Central River below Nugget Creek 161 Crater Lake outlet 162 North Fork of Grand Central River at pipe intake 165 North Fork of Grand Central River near ditch intake 166 North Fork of Grand Central River at the forks 167 Gold Run near mouth of canyon 168 Thompson Creek near ditch intake 170 Nugget, Jett, and Morning Call creeks 172 Miscellaneous measurements 173 Kruzgamepa River drainage basin 173 Description 173 Kruzgamepa River at outlet of Salmon Lake 175 Kruzgamepa River above Iron Creek 182 Iron Creek drainage basin 183 Description 183 Dome Creek below Hardluck Creek 184 Iron Creek below Canyon Creek 185 Iron Creek above the tunnel 185 Iron Creek at mouth 187 Iron Creek flume at intake 188 Pass Creek below dam site 189 Smith Creek below Swift Creek 191 Middle, Osborn, and West End creeks 193 Miscellaneous measurements 194 Kuzitrin River drainage basin 195 Description 195 Kuzitrin River at Lanes Landing 196 Miscellaneous measurements 200 Kougarok River drainage basin 200 Description 200 Kougarok River and Homestake ditch at intake 201 6 CONTENTS. Page. Detailed descriptions and measurements — Continued. Kuzitrin River drainage basin — Continued. Kougarok River drainage basin — Continued. Kougarok River below Henry Creek 205 Kougarok River above Coarse Gold Creek 206 Taylor Creek at Cascade intake 209 Henry Creek at mouth 210 Coarse Gold Creek near mouth 213 North Fork above Eureka Creek. 215 Ditches 217 Homestake ditch at penstock 217 North Star ditch above siphon 218 Cascade ditch 219 Miscellaneous measurements 219 American River drainage basin 221 Serpentine River drainage basin 222 Description 222 Quartz Creek above Bismark Creek 223 Miscellaneous measurements 223 Goodhope River drainage basin 223 Description 223 Goodhope River below Esperanza Creek 224 Miscellaneous measurements 226 Inmachuk River drainage basin 226 Description 226 Inmachuk River below Logan Guich 227 Miscellaneous measurements 229 Kugruk River drainage basin 229 Description 229 Imuruk Lake 230 Kugruk River below Fairhaven ditch intake 232 Kugruk River above Reindeer Creek 232 Chicago Creek at coal mine 234 Miscellaneous measurements 234 Fairhaven ditch system 235 Description 235 Fairhaven ditch at intake of upper section 236 Fairhaven ditch at Camp 2, upper section 237 Fairhaven ditch at Snow Gulch 238 Miscellaneous measurements 239 Kiwalik River drainage basin 240 Description 240 Kiwalik River below Candle Creek 242 Quartz Creek below the forks 243 Glacier Creek above intake of Candle ditch 244 Dome Creek at siphon crossing 246 Hunter Creek near ditch intake 246 Miscellaneous measurements 248 Bear Creek drainage basin 249 Description 249 Miscellaneous measurements 249 CONTENTS. 7 Page. Water power, by F. F. Henshaw 249 General conditions 249 Power sites 251 Ditches, by F. F. Henshaw 255 Introduction 255 Methods of construction 258 Flumes 260 Siphons and pipe lines " 262 Seepage losses, by G. L. Parker 263 Placer mining, by Alfred H. Brooks 269 Sources of information 269 Historical sketch 270 Cost of placer mining 272 Methods 276 Sources of information 276 Prospecting 277 General conditions 277 Prospecting by chum drills 278 Power drills 278 Hand drills 279 Comparative merits of power and hand drills 280 Sampling 281 Drilling season 282 Reliability of data procured by drilling 282 Prospecting by shaft 282 Choice of prospecting methods 283 Mining 285 General principles 285 Rocker and long torn 285 Open-cut mining 286 Hydraulic mining 289 Elevators 290 Dredging 292 Underground mining 297 Summary of placer mining 301 Index 305 ILLUSTRATIONS. Page. Plate I. Map of Seward Peninsula In pocket. II. Typical topography, Seward Peninsula 12 III. A, Upper Grand Central River valley; B, Glaciated valley near Mount Osborne 13 IV. Geologic map, Seward Peninsula 32 V. A, Price current meters; B, Measuring Grand Central River 56 VI. A, Candle ditch, Fairhaven district; B, Homestake ditch, showing Bod work 258 VII. Rock cut around Cape Horn on Miocene ditch 259 VIII. A, Flume on Ophir Creek; B, Flume of Topkok ditch, near Bluff... 260 IX. A, Mining with rocker on beach at Bluff, 1900; B, Using long torn near Nome 284 X. A, Open-cut mining on bench of Glacier Creek; B, Groundsluicing on Glacier Creek 286 XI. A, Groundsluicing with hydraulic giant on Anvil Creek; B, Mining with horse scrapers on Goldbottom Creek 287 XII. A, Open-cut mining with derrick and bucket hoist on Ophir Creek; B, Placer mining with track and incline on Ophir Creek 288 XIII. A, Open-cut mining with hand trams on Ophir Creek; B, Mining with steam shovel on Anvil Creek 289 XIV. A, Hydraulic mining on Daniels Creek; B, Underground mining in frozen alluvium near Nome 290 XV. Hydraulic elevator on Glacier Creek 291 XVI . Gold dredge on Solomon River near mouth of Johnson Gulch 292 XVII. A, Headframe and sluice boxes for underground mining operations in Nome; B, Surface equipment of underground mine near Nome, using aerial tram and self-dumping bucket 298 Figure 1. Hydrograph of typical streams and rainfall stations of Seward Peninsula for 1908 20 2. Diagrammatic cross section of valley showing different types of placers 41 3. Sketch map and profile of high bench gravels south of King Moun- tain 42 4. Diagrammatic section of beach placers 45 5. Sketch map of Nome region showing distribution of placers 46 6. Diagrammatic cross section showing beaches near Nome 47 7. Cross section of stream showing method of measuring 55 8. Discharge curves for Henry Creek at mouth 58 9. Discharge, area, and mean velocity curves for Canyon ditch at intake 59 10. Diagram showing gold production of Seward Peninsula, 1897-1910. . 271 11. A Klondike rocker 286 12. Diagrammatic section of underground placer mine showing method of hoisting and thawing with steam 299 8 SDllFACE WATER SUPPLY OF SEWARD PENINSULA. ALASKA. By F. F. Henshaw and G. L. Parkeb. INTRODUCTION. By Alfred H. Brooks. SCOPE OF WORK. This report presents the result of stream-flow measurements made in Seward Peninsula during the years 1906 to 1910, inclusive. The geography, geology, and meteorology of the peninsula are first briefly discussed, inasmuch as they have a controlling influence on the run-off, but in this introductory part of the report no attempt is made at a final analysis of the many geologic problems involved, which have been considered at greater length in the several reports of the United States Geological Survey^ relating to Seward Peninsula. 1 These reports include the papers listed below. All except those marked by an asterisk, which indicates that the Geological Survey's stock of the publication is exhausted, may be obtained on application to the Director of the United States Geological Survey, Washington, D. C. Preliminary reports on the Cape Nome gold region, Alaska, by F. C. Schrader and A. H. Brooks. In a special publication. 1900. 56 pp. A reconnaisance of the Cape Nome and adjacent gold fields of Sev/ard Peninsula, Alaska, in 1900, by A. H. Brooks, G. B. Richardson, and A. J. Collier. In a special publication entitled " Reconnaissances in the Cape Nome and Norton Bay regions, Alaska, in 1900." 1901. 180 pp. A reconnaissance in the Norton Bay region, Alaska, in 1900, by W. C. Mendenhall. In a special publication entitled "Reconnaissances in the Cape Nome and Norton Bay regions, Alaska, in 1900." A reconnaissance of the northwestern portion of Seward Peninsula, Alaska, by A. J. Collier. Professional Paper 2. 1902. 70 pp. The tin deposits of the York region, Alaska, by A. J. Collier. Bulletin 229. 1904. 61 pp. ♦Recent developments of Alaskan tin deposits, by A, J. Collier. In Bulletin 259. 1905. pp. 120-127. The Fairhaven gold placers, Seward Peninsula, by F. H. Moffit. Bulletin 247. 1905. 85 pp. The York tin region, by F. L. Hess. In Bulletin 284. 1906. pp. 145-157. Gold minmg on Seward Peninsula, by F. H. Moffit. In Bulletin 284. 1906. pp. 132-141. The Kougarok region, by A. H. Brooks. In Bulletin 314. 1907. pp. 164-181. *Water supply of Nome region, Seward Peninsula, Alaska, 1906, by J. C. Hoyt and F. F. Henshaw. Water- Supply Paper 196. 1907. 52 pp. Water supply of the Nome region, Seward Peninsula, 1906, by J. C. Hoyt and F. F. Henshaw. In Bulletin 314. 1907. pp. 182-186. TheNome region, by F. H. Moffit. In Bulletin 314. 1907. pp. 126-145. Gold fields of the Solomon and Niukluk river basins, by P. S. Smith. In BuDetin 314. 1907. pp. 146-156. Geology and mineral resources of Iron Creek, by P. S. Smith. In Bulletin 314. 1907. pp. 157-163. The gold placers of parts of Seward Peninsula, Alaska, including the Nome, Council, Kougarok, Port Clarence, and Goodhope precincts, by A. J. Collier, F. L. Hess, P. S. Smith, and A. H. Brooks. Bulle- tin 328. 1908. 343 pp. Investigation of the mineral deposits of Seward Peninsula, by P. S. Smith. In Bulletin 345. 1908. pp. 206-250. The Seward Peninsula tin deposits, by Adolph Knopf. In Bulletin 345. 1908. pp. 251-267. Mineral deposits of the Lost River and Brooks Mountain regions, Seward Peninsula, by Adolph Knopf. In Bulletin 345. 1908. pp. 268-271. Water supply of the Nome and Kougarok regions, Seward Peninsula, in 1906-7, by F. F. Henshaw. Id Bulletin 345. 1908. pp. 272-285. 9 10 SUKFACE WATER SUPPLY OF SEWARD PENINSULA. The general features of the topography herein described are also shown graphically on the map of the peninsula reproduced as Plate I (in pocket). This map is based on surveys made during the years 1900 to 1909, inclusive. Those who are interested in the details of the topography are referred to the several maps ^ which have been published by the Geological Survey. The occurrence and distribution of the gold placers are summarized in the section devoted to geology. At present the mining of the placer gold is the only incentive to the utilization of the stream flow. Methods and costs of mining are briefly considered in the last section of this volume. Plans were under consideration as early as 1903 for the systematic investigation of the water resources of Alaska, but the need of devot- ing the Alaskan appropriation to what was believed to be more important work prevented the prosecution of such an investigation. In 1906 a plan which contemplated the investigation of the water resources of the most important Alaska placer districts was formu- lated, but inasmuch as the funds available were sufiicient to investi- gate only one area in the first year, the Nome district was chosen as that in which information concerning water resources would be of greatest value. In the foUowing year similar investigations were begun in the Fairbanks district. The original plan contemplated Geology of the Seward Peninsula tin deposits, by Adolph Knopf. Bulletin 358. 1908. 72 pp. *Water-supply investigations in Alaska, 1906 and 1907, by F. F, Hensbaw and C. C. Covert. Water-Supply Paper 218. 1908. pp.156. Geology of the Seward Peninsula tin deposits, by Adolph Knopf. Bulletin 358. 1908. 72 pp. Recent developments in southern Seward Peninsula, by P. S. Smith. In Bulletin 379. 1909. pp. 267-301. The Iron Creek region, by P. S. Smith. In Bulletin 379. 1909. pp. 302-354, Mining in the Fairhaven precinct, by F. F. Henshaw. In Bulletin 379. 1909. pp. 355-369. Water-supply investigations in Seward Peninsula in 1908, by F. F. Henshaw. In Bulletin 379. 1909. pp. 370-401. Geology and mineral resources of the Solomon and Casadepaga quadrangles, Seward Peninsula, by P. S. Smith. Bulletin 433. 1910. 227 pp. A geologic reconnaissance in southeastern Seward Peninsula and the Norton Bay-Nulato region, Alaska, by P. S. Smith and H, M. Eakin. Bulletin 449. 1911. 156 pp. Notes on mining in Seward Peninsula, by P. S. Smith. In Bulletin 520. 1912. pp. 339-344. Geology of the Nome and Grand Central quadrangles, Alaska, by F. H. Moffit. Bulletin 533. (In preparation. ) 1 Such of the following maps as are for sale may be purchased from the Director of the Survey. Seward Peninsula, northeastern portion of, topographic reconnaissance map of; scale, 1:250,000; by D. C. Witherspoon and C. E. Hill. In Bulletin 247. For sale at 50 cents each, or $30 a hundred. Seward Peninsula, northwestern portion of, topographic reconnaissance map of; scale, 1:250,000; by T. G. Gerdine and D. C. Witherspoon. In Bulletin 328. For sale at 50 cents each, or $30 a hundred. Seward Peninsula, southern portion of, topographic reconnaissance map of; scale, 1:250,000; by E. C. Bar- nard, T. G. Gerdine, and others. In Bulletin 328. For sale at 50 cents each, or $30 a hundred. Seward Peninsula, southeastern part of; by D. C. Witherspoon, W J. Peters, H. M. Eakin, and others; scale, 1:250,000. In Bulletin 449. Grand Central quadrangle; scale, 1:62,500; by T. G. Gerdine, R. B, Oliver, and W. R. Hill. Forsaleat 10 cents each, or $6 a hundred. Nome quadrangle; scale, 1: 62,500; by T. G. Gerdine, R. B. Oliver, and W. R. Hill. For sale at 10 cents each, or $6 a hundred. Casadepaga quadrangle; scale, 1: 62,500; by T. G. Gerdine, W. B. Corse, and B. A. Yoder. For sale at 10 cents each, or $6 a hundred. Solomon quadrangle; scale, 1: 62,500; by T. G. Gerdine, W. B. Corse, and B. A. Yoder. For sale at 10 ceats each, or $6 a hundred. INTKODUCTION. 11 Rye seasons of observation in each district, but it bas not been pos- sible to adhere strictly to this plan. Even five years of observation by no means furiaishes absolutely reliable data on minimum run-off, but it is believed that the results herein set forth will be sufficient for general purposes. They should, of course, be supplemented by more detailed records where large investments are to be made in projects depending for tTieir success on the maintenance each year of a certain minimum flow. The hydrometric surveys whose results are published in this report were carried on under the appropriation for the investigation of the mineral resources of Alaska by engineers detailed for this purpose from the water-resources branch of the Geological Survey. Credit should be given to John C. Hoyt, assistant chief hydrographer, who personally began these surveys in 1906 and has since that time super- vised the technical part of the field work. Mr. Hoyt, in company with F. F. Henshaw, began investigations at Nome in June, 1906, conducting a reconnaissance northward to the Kigluaik Mountains (locally known as the Sawtooth Range), and covering the more important part of the producing placer district. A number of gaging stations were established by Mr. Hoyt before he left Alaska, early in August. The work was carried on by Mr. Henshaw for the remainder of the year and was continued by him with the help of one assistant during the three succeeding years. Stream-flow measurements have been limited each season to the period between the middle of June and the early part of October. In 1907, after assisting Raymond Richards to start the work south of the Kigluaik Mountains, Mr. Henshaw proceeded to the Kougarok district, where he spent the greater part of the season. In 1908 A. T. Barrows was assigned to assist Mr. Henshaw as junior engineer, and spent most of his time during that season in the Nome and Kougarok regions. Mr. Henshaw worked in the Fairhaven district from July 23 until the severe frosts came, during the first week of September. The rest of September was spent in the southern part of the peninsula. Messrs. Henshaw and G. L. Parker left Nome on June 13, 1909, for the Fairhaven district, by way of Nome River, Salmon Lake, Lanes Landing, and the head of the Kougarok, reestablishing on the way as many gaging stations as coifld be visited. New gaging stations were established on many of the larger streams of the northern slope of the mountains, and the work was left in charge of Mr. Parker. Mr. Henshaw returned by steamer from Candle to Nome, and spent the rest of the season in southern Seward Peninsula, giving special atten- tion to the Nome, Kougarok, and Council districts. In September, 1910, Mr. Parker, who had been investigating the water resources of the Fairbanks region, visited a number of gaging 12 SUEFACE WATEK SUPPLY OF SEWARD PENINSULA. stations near Nome and obtained such data as various cooperating companies and individuals had collected earlier in the year. The records for 1910 are not so complete as those of the previous years, but they serve to extend the observations over a longer period and thus add value to the results. This report has been prepared by Mr. Henshaw, with the assistance of Mr. Parker. ACKNOWLEDGMENTS. Except for the cordial cooperation of many residents of Seward Peninsula this work could not have been made so complete as it is with the comparatively small allotments that could be made to it. The mine and ditch operators were quick to realize the value of these investigations, and have at all times shown a cordial spirit in assisting the engineers by every means in their power. Many have rendered most valuable assistance in making gage readings, in furnishing stream-flow records made under private auspices, and in affording facilities to engineers during their periodic visits. A complete list of all who have aided the work would be almost a roster of the placer-mine operators of the peninsula. Special thanks are due to the following persons and companies : In the Nome region : B. Deleray, manager, and the employees of the Miocene Ditch Co.; C. H. Munro, manager, and the employees of the Wild Goose Mining & Trading Co.; Japhet Lindeberg, president, and the employees of the Pioneer Mining Co. ; the Cedric Ditch Co. ; the Gold Beach Devel- opment Co.; the United Ditch Co.; W. L. Leland; J. E. Styers; Arthur Gibson; George M. Ashford, and Frank Was key. In the Kougarok region: J. M. Davidson, president, and the employees of the Kougarok Mining & Ditch Co. ; A. J. Stone, general manager, and the employees of the Taylor Creek Ditch Co.; Samuel Schram, manager, and the employees of the Pittsburg-Dick Creek Mining Co., and C. F. Merritt. In the Fairhaven district: Employees of the Fair- haven Water Co.; the Candle- Alaska Hydraulic Gold Mining Co., and L. A. Sundquist. A considerable number of discharge measurements made by private engineers and others have been furnished to the Survey. Among those to whom special acknowledgment is due for furnishing data of this kind are C. H. Munro, W. H. Lanagan, A. B. Shutts, and R. G. Smith, of the WHd Goose Mining & Trading Co.; C. T. Law, of the Taylor Creek Ditch Co.; F. F. MiUer and J. W. Warwick, of the Mio- cene Ditch Co., and H. M. Long and R. S. Dimmock, of the Candle- Alaska Hydrauhc Gold Mining Co. Thanks are also due to the many gage readers scattered throughout the peninsula, who have rendered efficient service. Specific acknowl- edgment is given to each reader under the record of the particular station with which he was connected. U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 314 PLATE III A. UPPER GRAND CENTRAL RIVER VALLEY, B. GLACIATED VALLEY NEAR MOUNT OSBORNE. TOPOGKAPHY. 13 Those not familiar with the conditions of travel in Seward Penin- sula can not realize at what expense of toil and hardship Mr. Henshaw and his assistants have worked. The travel was practically all on foot, and as each engineer had many gaging stations to visit some of the journeys made were little short of marvelous. The field season is short, and the engineers felt in duty bound to collect the greatest number of records possible. They have shown a spirit of self sacrifice which does high credit to them as individuals and to the profession to which they belong. TOPOGRAPHY. By Philip S. Smith. Seward Peninsula forms the westernmost part of the mainland of Alaska. It lies just south of the Ai'ctic Circle and has a maximum length east and west of about 225 miles and a width north and south of about 150 miles, including an area of about 20,000 square miles. The general features of this region are well shown by Plate I (in pocket) and by Plate II, but this graphic representation may be sup- plemented by brief verbal description. The peninsula comprises three main topographic provinces— a low- land skirting much of the coast, an elevated region with a relief up to about 2,000 feet (Pl. II), and a belt of mountains having a maximum elevation of 4,700 feet (PI. III). Although presenting these three different types of land formes, Seward Peninsula as a whole may be referred to the central plateau province of Alaska, which lies between the Alaskan or Pacific mountain system on the south and the Endicott or Hocky Mountain ^ system on the north. The lowland province, which almost forms a girdle around the peninsula, shows by the character of its material that it was made by the deposition of stream and marme gravels on the floor of the sea and was subsequently uplifted, forming a coastal plain. This plain shows but slight relief, nowhere rismg more than 300 feet above the sea, though its continuity is interrupted here and there, as at Topkok Head, Cape Nome, and Cape Prince of Wales, where the second prov- ince abuts on the coast. It is of recent origin, for it is but little dis- sected by the streams which flow across it. Its surface is covered with a rank growth of grass, but trees and even bushes are practicaUy absent on the interstream areas, and stunted willows and alders form only a narrow fringe along the watercourses. Its width varies, but nowhere exceeds 25 miles. By far the greater part of Seward Peninsula faUs into the second physiographic division, the plateau provmce. This province is char- acterized by more or less elevated country, much dissected by streams, so that its general appearance is hilly. It occupies the northern and J Brooks, A. H., Geography and geology of Alaska: Prof. Paper U. S. Geol. Survey No. 45, 1906, PI. VII. 14 SUKFACE WATEK SUPPLY OE SEWAED PENINSULA. southern parts of the penhisula on either side of the mountain range. Collier * describes the portion south of the mountain as follows : To the south of the mountains is, as abeady stated, a highland mass whose summits range from 800 to 3,000 feet in elevation. The slopes of this upland are in many places broken by well-marked benches. * * * This highland area is essentially one of irregular topography with no well-defined system of ridges. The watercourses flow in broad, deeply cut valleys, whose slopes ascend gradually to the divides. The summits are rounded, but are broken by numerous rocky knobs, many of which are carved into fantastic shapes. These castellated peaks are very characteristic features of the topography, and their preservation plainly indicates the absence of regional glaciation. * * * The general trend of the larger valleys is north and south, and these block out broarl ridges, whose margins are scalloped by the minor tributaries. Many of the so-called mountains in Seward Peninsula — for instance, the York Mountains, in the western part — are merely dissected rem- nants of the general plateau just described. If mountains of this class are excluded, there appear to be only three distinct mountain ranges in Seward Peninsula, and perhaps even this number should be reduced, for the Kigluaik-Bendeleben Mountains and the Darby Kange may be continuous. The only other range is that joining the divide between Kiwalik and Buckland rivers. The highest points in this range do not exceed 2,600 feet, and its average elevation is probably less than 2,000 feet. The Kigluaik-Bendeleben Range has an average elevation of 3,000 to 3,500 feet, the highest points rising more than 4,000 feet (PL III, B). The range seems to be characterized by a single main ridge; that is, the slopes culminate in a single continuous divide, containing all the highest points, with no equally elevated ridges approximately parallel to it. The ridge line is fairly straight and exhibits but few irregularities. In general the range is unsymmetrical, with the cul- minating points nearer the abrupt northern side than the more gentle southern slope. This lack of symmetry is particularly noticeable in the Kigluaik Mountains, but is not so marked in the Bendeleben Mountains, for in the latter the line joining the highest points is almost symmetrically placed. As has already been noted, the Darby Mountains may be considered as a southward continuation of the Kigluaik and Bendeleben moun- tains. This range rises to an average height of 2,500 to 3,000 feet and has features practically the same as those in the Kigluaik- Bendeleben Kange already noted. The western slopes rise abruptly from a low plain not more than 400 feet above sea level, so that the relative relief is strong. The eastern slope is somewhat similar to the south side of the Kigluaik-Bendeleben Mountains, where the transi- tion to the plateau province is not weU marked, and the two grade into each other with no sharp luie of demarcation. The vaUeys in both these ranges have recently been occupied by alpine glaciers. These vaUeys are separated only by narrow ridges, 1 Collier, A. J., and others, The gold placers of parts of Seward Peninsula, Alaska: Bull. U. S. Geol. Survey No. 328, 1908, p. 46. CLIMATE. 15 and the knifelike character of many of the divides is perhaps the most striking feature of the mountains. Broad amphitheaters with nearly perpendicular cliffs rising a thousand feet or more at their heads are common in the mountain province and add much to the grandeur of the scenery. (See PL III.) The position and physical features of the mountains have an impor- tant bearing on the water supply. As is explained more fully on pages 31-32, the mountains receive a much heavier precipitation than the lower areas and therefore yield a greater amount of water. Not only is the precipitation greater, but the snow stored in the deep gla- cial cirques maintains a more constant run-off throughout the summer than is afforded by areas where the stream flow is directly dependent upon the rainfall. CLIMATE. By F. F. Henshaw and G. L. Parker. GENERAL FEATURES. The meteorologic records of Alaska as a whole indicate a great diversity of climatic conditions. Abbe ^ in his discussion of climate in Alaska shows very clearly this diversity and outlines systemati- cally the general relations of temperature and precipitation between certain geographic subdivisions, termed '^ provinces.'' Seward Penin- sula lies between the ' 'Bering Sea coast climatic province" and the "Arctic coast climatic province,'' as designated by Abbe. His analysis shows that the climate in this region is subject to consider- able local variation, and data obtained since 1906 confirm his conclu- sion. The records also show a greater local difference in precipita- tion than in temperature, which is no doubt due chiefly to the fact that two mountain ranges, the Kigluaik and the Bendeleben, inter- cept a large percentage of the moisture in the winds blowing from Bering Sea. The rainfall in the portion of the peninsula lying north of the mountains is similar to that in the northern arid province; and the rainfall in the southern portion, though less, is not greatly at variance with the amount contributed to the Bering coast. The pre- cipitation in the mountainous areas, however, is considerably greater, as is shown principally by the run-off of streams that have their source in the mountains, and to a less extent by actual rainfall observations. Specific acknowledgment is made to the Weather Bureau of the Department of Agriculture for many of the instru- mental records included in this report. In the following pages an attempt has been made to collect avail- able data concerning temperature and precipitation. The accom- panying tables summarize the records made in the region from 1877 to the close of 1910 and serve to show, in compact form, certain gen- eral characteristics that are considered in greater detail later. I Abbe, Cleveland, jr., Prof. Paper U. S. Geol. Survey No. 45, 1906, pp. 189-200. 16 SUKFACE WATEE SUPPLY OF SEWAKD PENINSULA. The following statement gives briefly the climatic conditions exist- ing in this area during the years 1899-1906: 1899. July, 4 rainy days; August, 14 rainy days; September, 14 rainy days; re- corded at Teller. 1900. June and July, warm and dry, tundra fires common; August to end of Septem- ber, rain. 1901. June to August, inclusive, cold and foggy with some rain; September and October, usually clear and cold with one or two hard rains of a few days' duration. 1902. June, dry; July, 10 rainy days; August, 6 rainy days; September, 3 rainy days; recorded at Teller. 1903. Summer warm; little rain, but considerable fog. 1904. June, dry. Rainy days as follows: Ten in July, 10 in August, 10 in Septem- ber; temperature moderate. 1905. Very wet and cold the whole season. 1906. Very warm and dry; tundra fires common. Maximum temperature recorded, 85° F. Summary of meteorologic observations at Nome, by years, 1907 to 1910, inclusive. Record. 1907 1908 1909 1910 16.69 11.17 9.46 17.47 76.65 62.50 44.25 39.40 69° 78° 70° 62° -32° -32° -33° -38° 30. 42° 31. 55° 30.13° 28.79° 17.64° 18.88° 17.17° 15.89° 29.86 29.78 29.87 29.82 148 122 163 150 47 49 55 40 170 195 147 175 103 84 70 114 for period. Total precipitation, rain and melted snow (inches) Total snowfall (inclies) Maximum temperature ( ° F.) Minimum temperature (° F.) Mean of daily maximum temperatures (° F.) , Mean of daily minimum temperatures (° F.) Mean barometer (inches) Number of clear days Number of partly cloudy days Number of cloudy days Number of days with rain or snow 13.70 55.70 30. 22° 17.40° 29.83 146 48 172 Summary of mean monthly precipitation recorded at stations on or near Seward Peninsula previous to 1906. Station and years. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. St. Michael 1877-1886 a Port Clarence 1895-96 & Omilak mine 1884-85 c 0.85 .83 .40 0.24 .01 .32 0.52 -.11 0.36 .18 .07 1.27 .02 .02 1.45 1.33 2.53 .50 3.27 1.30 4.02 1.10 1.70 .08 .23 1.15 .04 .45 0.75 .02 .18 a St. Michael is located on the southern shore of Norton Sound, about 120 miles southeast of Nome. The means were computed by Abbe (Prof. Paper U. S. Geol. Survey No. 46, pp. 189-200) from records extending over a period of 7 years and 6 mouths. Mean annual precipitation, 18.11 inches. b Port Clarence lies on the western coast of Seward Peninsula and south of Bering Strait. The data are taken from a report on the introduction of domestic reindeer in Alaska, by Sheldon Jackson, published in 1896. Mean precipitation per year for the period, 5.58 inches. c The Omilak mine is located in the eastern part of Seward Peninsula, about 35 miles north of Golofnin Sound. The values are taken from Abbe's tables, mentioned above. TEMPERATURE. Practically the only temperature records for this region that extend over a long period of years are those made at Nome by Arthur Gibson, a volunteer observer of the Weather Bureau. The results of these observations are given in full in the following tables and the yearly average has been summarized in a preceding table. These records are of special value in indicating the length of the open season and the range of temperature. CLIMATE. Daily mean temperature {°F.) at Nome for 1907. 17 Day. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. 1 23.5 29.5 14.0 25.5 15.5 25.0 24.5 11.5 -8.0 4.0 20.5 25.0 24.0 18.5 16.0 - .5 -7.5 -20.0 - 6.0 11.5 11.5 1.5 23.0 21.5 23.5 14.0 13.5 10.5 4.5 .5 .0 8.5 - 1.0 - 5.5 - 2.0 -11.5 -13.5 - 1.5 -10.0 -15.0 -13.0 -14.0 -25.0 -20.5 -19.5 -27.5 -22.0 -18.5 -22.5 -15.5 -22.5 -18.0 - 6.0 - 1.5 12.5 25.0 24.5 17.5 6.5 9.5 1.5 20.5 24.0 2.3.0 20.5 28.5 26.0 25.5 29.5 29.0 21.5 7.0 - 4.5 -5.0 - 4.0 15.0 18.5 -5.0 - 9.0 -15.5 -17.0 -13.5 16.0 10.0 -8.0 -10.0 -14.5 -18.5 -19.5 - 6.5 - 0.5 15.0 13.5 12.5 13.0 - 0.5 .0 - 2.0 10.0 3.0 15.0 26.0 33.5 29.0 17.5 13.5 5.5 7.0 8.0 18.5 24.0 26.0 33.0 33.0 35.5 37.5 37.0 34.0 36.0 36.0 37.5 37.0 40.0 37.5 35.5 33.5 38.5 43.0 43.5 39.5 26.0 20.5 22.5 28.0 26.0 25.5 30.0 31.0 31.0 32.0 36.0 37.5 43.5 39.0 36.5 34.0 29.5 34.5 36.0 40.5 38.5 41.0 45.0 42.5 44.0 41.0 46.0 41.0 38.0 52.0 50.5 48.0 51.0 57.5 50.5 42.0 42.5 43.5 45.0 40.0 42.0 45.0 43.5 52.5 52.5 49.0 47.0 42.5 41.5 44.0 45.5 48.5 44.5 46.0 49.0 50.0 46.5 46.0 51.5 56.5 57.5 49.0 49.5 51.0 52.0 51.5 49.0 46.5 46.5 49.5 49.0 48.5 54.0 53.0 51.0 52.0 47.0 46.0 51.5 56.0 57.5 54.0 54.5 54.5 54.0 48.0 44.0 52.0 58.0 50.5 50.0 54.5 57.5 69.5 56.0 53.5 50.5 48.5 51.0 48.5 54.0 53.0 48.5 42.0 38.5 40.0 45.5 45.5 44.0 47.0 45.5 41.0 40.5 41.0 37.0 41.5 42.0 38.5 41.0 44.5 46.5 47.5 46.5 42.0 39.5 40.0 45.5 38.0 39.0 36.0 36.5 35.5 43.5 38.0 36.0 37.5 39.0 45.5 42.0 45.0 45.0 42.0 40.0 33.0 25.5 26.5 25.5 26.0 32.5 33.0 24.0 22.0 26.0 26.0 19.0 21.0 23.0 23.5 26.5 23.0 27.0 20.0 27.0 27.0 25.0 29.0 34.0 29.5 21.5 19.5 9.5 7.5 7.0 11.5 13.0 3.5 6.0 8.5 6.0 2.5 - 3.0 - 0.5 8.5 18.5 19.0 29.5 28.0 33.5 23.0 20.0 19.5 13.5 9.5 14.0 6.'5 2.5 4.5 -3.0 - 4.5 - 4.5 1.5 .5 - 3.5 4.5 2 18 3 17 4 15 10.5 6 16.5 7 18 8 20.5 9 17.5 30 5.0 11 - 8.5 12 -10 13 - 9 14 — 1.5 15 13.5 16 29 17 30 IS 23.6 19 17.6 20 7.5 21 6.5 22 6 23 1 24. - 2 25 — 8 26 —10.5 27 -10 28 -13.5 29 —17 30 —17 31 —25 Mean 11.9 -7.6 6.6 19.0 34.3 45.6 50.0 49.8 41.1 24.5 9.6 4.6 Daily mean temperature {°F.) at Nome for 1908. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. -24.5 6 24.6 8 37 36 67.5 45 46 32.5 11.5 -17.5 7 31 - 0.5 35.5 44.5 65.5 46.5 41 35 13.5 - 2 15.5 20 - 1.5 32 46.6 49 45.5 43.5 36.5 5 4 21.5 4.5 - 1.5 29.5 48 49.5 46.5 41 38.5 - 3.5 - 8 22 5.5 4.5 29.5 41 48.5 47.5 37 39.5 - 2.5 -16.5 22 17 10 29.5 36.6 45.5 42 39.5 29 2.5 -24. 5 10 7 6.5 27 34.5 46 41 35 24 6 -28.5 9.5 - 0.5 11 28.5 34.5 60 41.5 38.5 28 7 -24 21.5 - 8 17 32 39 49.5 46.5 41.5 30.5 6 -14 18.5 18.6 30 36.5 51 55.5 39.5 29 - 3 6 21 6.5 10.6 28.5 36 46.5 52.5 33.6 26 - 6.5 15.5 26 4.5 8 30 36.5 46 52 34 27.5 3 7.5 26 11.5 30 42 51.5 50 35 22 3.5 3.5 23 - 0.6 8 38.5 43 52.5 48.5 33 17 4 13 25 2 21.5 38 39 53 48.5 36 29 13.5 19.5 18.5 - 2.6 19.5 43 44.5 58.5 48.5 41 20.5 15.5 4.5 21 - 2.5 8.5 45 45 58 49.5 41 16 10 -17. 5 12 - 8.5 6.6 46 40 64 46.5 35.5 18 11 -27.5 6 -16 14 50.6 44 57.5 47 34.5 28.5 9 -27 8 -20 23.5 44.6 51 56 47.5 32 31 9 -18 8 -20 20 45 46 50 49.5 30 28 3 - 8 - 8.5 - 6.5 16 43.5 42.5 62 49 31 24.5 0.6 13 -19 17 8.5 44 48.5 48.5 48 29.6 12 2 15 - 8.5 29.5 8.6 40.5 59.6 46 47 28 11 12.5 21 14.5 31 16.5 42.5 63.5 48.5 44.5 33 26.5 27.5 24 17.6 29.5 11 46.5 61.6 47.5 47.6 33.5 28 28 23.5 20 19 18 43 65.5 48 46.5 30 30 27.5 26.5 16.5 17 34 40 61 46 47.5 30 28.5 24 25 20.5 13.6 37.5 38 57 48.5 46 3a 6 23.5 26.5 21 22.5 36.5 41 65.5 48.5 43.5 32.6 21 28.5 12.5 9.5 34 48 47 17.5 .08 13.8 7.3 13.6 37.6 46.2 51.2 47.2 36.5 26.1 9.8 Dec. 29 25.5 27 31 28 30 28 25 26 26 18.5 13 5 2.5 1 13.6 22 13 10 6.6 13 13 9 7.5 2.5 - 7.6 -12 0.6 7.5 22.5 12 14.4 63851°— wsp 314—13- 18 SUEFACE WATEK SUPPLY OF SEWARD PENINSULA. Daily mean temperature {°F.) at Nome for 1909. Day. Jan. Feb. Mar. Apr. May. June. July.o Aug. Sept. Oct. Nov. Dec. 1 -5 7.5 6 18 22.5 25 21.5 21.5 27 28 19.5 15.5 2 - 9.5 -14 -10.5 -11 -15 -10 -17.5 - 9 - 3 - 1 - 7 - 6.5 -18.5 -23 -15.5 -13 -18.5 -16.5 1.5 12.5 16.5 12 - 2 3 2 - 9.5 8.5 10 12 4.5 8.5 8.5 7 6.5 6.5 - 9.5 -17.5 - 5.5 - 2.5 - 6.5 7.5 6.0 - 7.0 - 8.5 -16.5 -10 - 9 -15 -18.5 -18.5 -18.5 -12.5 3 10 - 5 -12 4 18.5 11.5 13 18 18.5 12.5 0.5 2.5 1.5 2.5 -10 -12.5 -14.5 -25.5 -16 -15 2 9 - 4 0.5 10 5.5 - 1.5 - 2.5 1.5 5 16 19 18 21.5 20 18 16 13.5 16.5 10 19.5 34 36 36.5 31 31.5 33.5 28 30 29 27 30 35 36.5 38 36.5 35 33.5 28.5 25.5 29 32 32 29 28 30.5 34.5 39.5 37 37.5 35 38 47 46 39 44 39.5 32 32 32 31.5 33.5 34.5 36.5 34 35 39 45 40.5 45 43 43 42 39.5 38 38 45 41.5 40.5 49.5 60.5 51 46 45.5 46.5 37.5 43.5 41 42 42 41.5 42 41.5 40 ; 55.5 55 46.5 50 43.5 48 47.5 49 5 53.5 45.5 47.5 47.5 48.5 54 62 57.5 51.5 48 50 53.5 58.5 57.5 50.5 51 49.5 48.5 47 49 48 46.5 43 43 39.5 42 49.5 56 54 51.5 48.5 47 47.5 45 42 43 45 37.5 36.5 37.5 32 34 32 38 40.5 39 40 36 32.5 35 31 29.5 26 28 24 26.5 28.5 25 28 29.5 34 35.5 29.5 27.5 26.5 21.5 20.5 22.5 23 24 27.5 26.5 26 24.5 29.5 33.5 34.5 35 33 29.5 26 26 27 22 19 17 19 15.5 14 25.5 29 28 25.5 24.5 26 31 29 25.5 24.5 23.5 11 13 20 13 12 6.5 8 15.5 9.5 3 - 6.5 0.5 -0.5 7 7.5 2 10.5 3 11 4 14.5 5 9 6 6 5 7 11 8 0.5 Q 6 10 3 U -12.5 12 -16.5 13 -3.5 14 ]5 -6.5 16 - 5 17 — 3.5 18 6.5 19 14 20 1 21 — 8.5 22 -17 28 -23 24 -18 25 3 26 23 27 23 28 -4.5 29 -15.5 30 13 31 18.5 Mean - .32 1.4 - 2.6 19.6 34.9 42.3 52.6 50.4 40.4 27.6 16.3 1.5 o Daily values for July are not available. Daily mean temperature i°F.) at Nome for 1910. Day. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.a 1 21 13.5 3.5 16 21 4.5 - 8 -22 -7.5 -11.5 -14.5 6 8 22.5 11.5 6.5 -10 -20.5 -20.5 -15 6 9 -10.5 -26 -23 -24 -25 -28 -23 -23 -24.5 -32 -31 -13.5 3.5 - 2.5 - 4.5 6.5 18 21.5 7.5 -13.5 - 3.5 1 5 11 19 9 10 7 8.5 2 2.5 0.5 7.5 11.5 11 - 7.5 - 5 2.5 - 5 -10.5 - 7 - 6.5 - 2 - 5.5 6 6 2.5 - 5 18 26 20.5 3.5 16 25 26 26 21.5 18.5 16.5 9 8 5 - 0.5 -11 -13 5 17 6 0.5 - 8 - 9 - 9 - 5 1 - 8 - 6.5 - 8 - 8 - 2.5 - 1.5 0.5 - 1 8.5 5.5 7.0 7.5 9.0 8.5 19.5 22.5 27.5 15 9 15 28 35.5 28.5 16 ~ 18.5 28.5 31.5 23.5 26.5 33.5 34.5 31 26.5 24 25.5 30 36.5 37.5 33.5 34 35 32 34 35 37 45 44.5 44.5 35 32.5 34.5 35.5 35.5 38.5 42.5 39.5 37 37 41.5 41.5 37 35.5 33.5 36 34 35.5 35.5 36 37 33.5 38 40.5 40.5 40 40 38 43.5 49.5 42 47.5 48 48.5 51 48 51.5 51.5 47 44.5 42.5 41 43.5 39.5 42.5 44.5 45.5 47.5 45 44.5 47 43.5 41.5 43.5 48.5 47.5 49 48.5 48.5 46.5 45.5 60.5 45 45 44.5 47 46 47 41 39.5 42.5 44 45 43 46 51 53 51 48.5 46 48 42.5 47.5 43 45.5 51 51 56.5 52 48 49.5 50 55.5 57 52 50 63.5 53.5 51 51 46 44.5 53 65.5 60.4 52.5 49 46 48.5 48 44.5 43.5 43.5 34.5 33 35 39 38.5 44 45 44.5 45.5 43.5 43 44 40.5 34 33.5 30 26.5 29 27.6 28.5 30 33.5 36 35 34 36.5 34.5 30.5 29 30 37.5 36.5 33.5 28.6 24.5 21 14.5 15.5 16 26 30 23 20 21.5 29 29 34 29 28.5 20.5 19 16 26 26 26 25.6 12 1 0.5 8 8 23.5 27.5 30 28 20 10 9.5 11.5 11 17.5 26.6 25.5 30 26.6 2 3 4 5 6 8 9 ]0 11 12 ^ 13 .... 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Mean - 6.0 1.9 6.1 5.9 32.2 39.9 45.8 48.3 44.8 28.4 20.1 0.56 • Daily values for December are not available. CLIMATE. 19 PRECIPITATION. When stream-gaging work was begun in the spring of 1906 it was necessary to obtain records of the rainfall at several places in order to find out the average precipitation over the general region. For this purpose precipitation stations were established at Nome, on the southern coast of the peninsula; at Salmon Lake, about 40 miles inland, south of the Kigluaik Mountains; at claim ^'No. 15 above," on Ophir Creek, near Council, in the eastern part of the region; and at Deering, on the northern coast of the peninsula. No records, however, were kept at Deering, and therefore all the data procured in 1906 were obtained from the area south of the mountains. In 1907 rain gages were placed at Black Point, near the head of Nome River; at the forks of Grand Central River, in the heart of the Kigluaik Mountains; and at Shelton and Taylor, north of the mountains. In 1908 the scope of the observations was extended and rainfall stations were established from the southern to the northern coast of the peninsula. Additional gages were placed at Iron Creek, near the east end of the Kigluaik Mountains; on Budd Creek, a tributary of American River; and at Candle, near the coast of Kotzebue Sound. In 1909 records were taken at Dahl instead of at Shelton. These stations were established by the Geological Sur- vey and the equipment was furnished by the Weather Bureau. All records were kept by volunteer observers. The location of these stations is shown on Plate I (in pocket) and other information in regard to them is summarized in the following table. Seward Peninsula precipitation stations. station. Desig- nation on Plate I. Lati- tude. \Zt Eleva- tion above sea level (feet). Observers. Date of records.* A B c D E F G H I J K 64 30 64 59 64 51 64 58 64 54 65 00 65 L3 65 22 65 42 65 38 65 55 • r 165 24 163 39 165 16 165 14 164 56 164 39 164 48 164 41 164 48 165 23 161 66 40 200 575 690 445 290 60 280 550 320 20 Arthur Gibson 1906-910. Ophir C. Arnold, H. Leland, and W. H. Sirdevan. F. F. Miller and George Peters Cornelius Edmunds, Fred Walford, and P. B. Chap- man, J. P. Samuelson and M. Donworth. Clyde Hager and George Lorimer. Lars Gunderson 1906, 1909, 1910. 1908,1909,1910. 1907,1908,1909. 1906, 1907. 1908,1909. 1907 1908 Black Point Grand Central Salmon Lake Iron Creek Shelton Dahl J. A. White 1909' 1910. 1907 1908 Taylor A. E. Edgtvet and A. G. Schraeder, J. P. Samuelson Budd Creek 1908. Candle. J. E. Fox, Ward Estey, and R. S. Dimmick. 1908,1909,1910. a The only continuous records available are those at Nome, which extend from June 14, 1906, to date. The records at the other stations, in most part, were kept only during the summer months. The results of the observations made at these stations have been tabulated below in order to show both the daily and the monthly 20 SUEFACE WATER' SUPPLY OF SEWASD PENINSULA. precipitation. The tables of daily precipitation are of particular value, for they permit direct comparison with the daily discharge measurements of the streams given on pages 68-249. (See fig. 1.) JUNE JULV AUG. SEPT. Figure 1.— Hydrograph of typical streams and rainfall stations on Seward Peninsula for 1908. The summaries by years of monthly precipitation are important in showing the local variation in different parts of the peninsula and the difference in the precipitation of successive years. CLIMATE. 21 Daily precipitation^ in inches, at stations in Seward Peninsula, 1906 to 1910, inclusive. Day. July, 1906. August. September. Octo- ber. Novem- ber. Decem- ber. Nome. Salmon Lake. Ophir. Nome. Salmon Lake. Ophir. Nome. Salmon Lake. Nome. 1 ' 0.14 0.20 .12 2 Trace, 0.04 3 . . 0.12 .35 .35 .10 .17 2.32 .31 .25 4 0.17 .07 .23 .28 0.01 .05 .03 5. ... . . 0.02 .23 1.30 .19 0.07 *"V*4i" Trace. 0.14 6 7 a 0.52 .37 .92 .14 0.17 g .01 g .29 .08 .12 .01 .13 10 11 .86 .01 .02 .01 .02 .02 12 .. .04 .10 13 .12 .01 14.. . .35 .03 .09 15 16 17 .10 .14 .16 .23 .28 .04 .01 .28 1.06 .99 .55 .16 .03 18 .01 19 .31 .31 20 .57 21 .25 .01 .01 .60 .25 .01 .80 22 23 .08 .27 .04 ■"".'ss" .22 .50 .22 24 .74 25 .04 .37 .30 .14 .15 .01 .78 .23 .05 .40 .32 .24 26 .23 .34 .08 27 .01 28.! !! 29 .38 30 31 .30 Total. Snowfall, in inches . 2.38 4.92 3.57 2.50 3.33 1.91 1.02 3.26 .93 (0 .32 (0 1.91 20.8 Day. Jan- ffi' Feb- ruary. March. April. May. June. July. Nome. Nome. Black Point. Salm- on Lake. Nome. Black Point. Salm- on Lake. Grand Central. 1 2 0.13 3 0.52 0.05 .03 .39 .08 .12 4 .40 5 .13 0.03 .48 .30 .01 0.12 .35 .13 .14 0.54 ■"■'." io' dOA2 6 .95 0.05 .08 d0.07 d.ll d 88 7 .. .36 d 14 8 d.24 9 10 .23 .87 .10 .12 "".'io' .10 11 .03 .02 .07 .01 .02 .05 .07 .04 .02 C.12 12 e 16 13 .07 .26 .28 e.07 14 .09 .04 <.13 15 Ml a Total, Jiily 1-7. b Total, Aug. &-7. cMost of the precroitation for October and November was in the form of snow; the snowfall was not measured. During June there was no measurable precipitation at any of the stations. d Estimated by comparison of stations. < July 10 to 16 the total was 0.66; July 17 to 25 the totalwas 1.49. These amounts were distributed in proportion to the amount of rainfall at Black Point and Salmon Lake. 22 SUEFACE WATEK SUPPLY OE SEWAKD PENINSULA. Daily precipitation, in inches, at stations in Seward Peninsula, 1906 to 1910, inclusive — Continued. Day. Jan- uary, 1907. Feb- ruary. March. April. May. June. July. Nome. Nome. Black Point. Salm- on Lake. Nome. Black Point. Salm- on Lake. Grand Central. 16 a 0.26 a. 06 0.56 a. 21 a. 34 6 0.46 0.05 0.07 cO.07 17 0.57 .09 0.08 .31 .08 .21 18 .63 .32 .38 .20 .06 .05 .04 .12 .04 .16 .28 ■"a26' .26 c.VA 19 c. 04 20 0.32 C.40 21 C.58 22 23 0.04 .04 .24 .02 .03 .20 .27 .02 .08 .22 .69 "■■.■26' .34 .22 .47 .04 .16 """."is' C.18 24 0.56 .30 .41 .04 .15 .75 .08 0.03 .07 C.17 25 26 27 28 29 30 .17 ...... ^. .08 31 Total. . Snowfall, in inches . 2.64 25.2 1.46 13.9 3.37 28.8 .10 1.12 1.31 2.62 2.31 2.08 1.94 1.79 3.61 July, 1907, cont. August. September. Day. Shel- ton. Tay- lor. Nome. Black Point. Salmon Lake. Grand Cen- tral. Shel- ton. Tay- lor. Nome. Black Point. Salmon Lake. 1 0.10 2 0.17 .02 .01 0.20 .09 .05 0.01 3 .15 .05 '"6.09' 0.14 .02 .06 .16 4 0.34 5 6 .10 """."i4" .20 .36 1.40 .33 .07 .10 7 8 . .07 .17 .61 .08 .10 g .45 10 .35 11 .02 .02 .08 .10 " '."6i' .10 .03 .09 :1^ .05 .07 .03 ■"":i2" .03 .20 .07 Tr. Tr. .03 .07 Tr. Tr. .15 .13 .60 12 Tr. .09 .04 .10 .56 .50 .15 .02 ""0.'46" .17 13 6.i9 .11 .04 .38 .07 .01 .05 .22 .06 14 0.01 .01 .01 .04 .06 .07 .22 15 16 .39 .65 .40 .70 .83 .40 .02 .48 .12 .02 .20 .14 .50 .20 .07 1.90 1.03 .02 17. . 18 19 20 0.14 Tr. Tr. .29 .08 Tr. .15 .06 .32 .17 21 .08 .22 .01 .01 .07 .02 .08 .03 .03 .04 22 23 .05 .53 .04 .01 .11 .02 1.02 .20 .07 .05 .07 24 .22 .03 .30 .22 .06 .05 .10 .10 .65 .15 ' ""."36' .12 25 .02 "".06 .05 .06 26 ,15 27 28 29. . .08 Tr. .05 Tr. .01 30 .12 .03 31 TotaL.. .71 .66 2.68 2.85 3.65 7.19 1.33 .96 1.41 3.26 2.26 a Estimated by comparison of stations. b Total June 1 to 16, inclusive. c July 10 to 18 the total was 0.66; July 17 to 25 the total was 1.49. These amounts were distributed in proportion to the amount of rainfall at Black Point and Salmon Lake. CUMATE. 23 Daily jyredpitation, in inches, at stations in Seward Peninsula, 1906 to 1910, inclusive- Continued. Day. September, 1907, contd. Octo- ber. Novem- ber. Decem- ber. Jan- uary, 1908. Feb- ruary. March. April. May. Grand Cen- tral. Shel- ton. Taylor. Nome. Nome. 1 0.05 0.01 0.03 .01 Tr. .33 Tr. .06 0.04 0.16 .23 .23 2 0.06 3 .. .04 .32 .04 ■"■.■62' .01 4 0.06 0.09 .15 6..-. .01 .09 .08 6 7 -. .07 .11 1.36 1.96 .66 .03 0.02 8 .01 ■■■■.■26' .12 .01 .27 .28 .04 .03 9 10 0.02 .04 11 12 .01 .02 .06 13 14 .05 .08 15 .17 Tr. .02 .11 0.03 .03 .09 16 17 .01 .08 18 Tr. .05 .01 .03 .02 19 20 Tr. .11 .14 21 ... . .03 .06 22 .04 .06 .19 23 .13 .03 .16 .05 24 Tr. .05 .05 25 O.05 0.21 .10 .06 26 27 28 .04 .03 29 30 31 Total... Snowfall, 5.03 .47 1.17 .16 .06 .30 6.75 .43 8.9 .76 11.95 1.19 3.1 .02 .3 .19 June, 1908. July. August. Day. Nome. Black Point. Shel- ton. Nome. Black Point. Grand Cen- tral. Iron Creek. Shel- ton. Tay- lor. Budd Creek. Nome. Black Point. 1 2 0.08 .13 "'6.' is' b 0*. 10 b.30 Tr. 0.01 Tr. 0.01 3 0.18 .02 .12 .02 .10 0.06 0.18 0.02 .72 .13 .43 .04 4 0.30 .09 .14 .30 .07 '6.'i2' .14 .25 .06 .93 6 .23 6 .05 7 . ... 8 9 10 .04 .20 .23 .22 .01 11 .37 .19 .04 .25 .52 .09 .44 .03 .11 ....... 0.10 .08 .34 12 .25 13 .10 14 .03 15..., .03 .04 16 Tr. .02 .01 17 18 Tr. .04 .21 .05 19 .05 .12 .33 20 .11 .02 Total estimated. b Estimated; gage installed July S. 24 SURFACE WATER SUPPLY OF SEWARD PENINSULA. Daily precipitations, in inches, at stations in Seward Peninsula, 1906 to 1910, inclusive- Continued. June, 1908. July. August. Day. Nome. Black Point. Shel- ton. Nome. Black Point. Grand Cen- tral. Iron Creek. Shel- ton. Tay- lor. Budd Creek. Nome. Black Point. 21 0.15 0.01 .14 22 Tr. 0.11 0.07 .41 .05 16 23 0.01 Tr. .02 0.06 .37 24 0.05 .09 25 02 26 .04 27 Tr. 28 0.30 ....... 29 .07 .80 .37 .06 .82 .78 ...... 30 1.20 1.50 .79 .56 .10 .40 '""."45" .21 31 .37 .34 Total 0.90 0.S7 0.44 2.10 2.30 4.02 i.e; 1.32 .68 .69 2.92 3.42 August, 1908, contd. September. Octo- ber. Day. Grand Cen- tral. Iron Creek. Tay- lor. Budd Creek. Can- dle.a Nome. Black Point. Grand Cen- tral. Iron Creek. Tay- lor. Can- dle. Nome. 1 0.13 Tr. 2 0.16 0.16 0.14 Tr. 0.16 3 0.18 05 4 . . .52 1.70 .20 0.42 .13 0.25 .35 05 5 6 .44 .09 .04 7 8 9 Tr. 10 11 .24 .06 .09 0.10 Tr. '"."63' 12 .70 .20 13 Tr. .15 .30 .10 .07 Tr. .12. Tr. 0.12 .24 14 15 .11 .27 .10 0.14 .25 16 .39 17 .18 18 -. Tr. .02 .02 19 .67 .61 .05 .08 '"".'32" .16 .11 20 Tr. .08 .09 21 Tr. 22 . ... .04 .10 Tr. * ' 23 .30 .80 .29 .02 .15 .12 * 24 25 Tr. .18 Tr. .06 .45 26 .04 27 16 28 Tr. 29 SO .. . 31 .60 .12 .37 .15 Total Snowfall, in inches . . 6.21 1.27 1.11 1.87 b.50 .52 .63 3.9 .72 9.0 .30 3.4 C.23 d.20 1.13 10.5 a Gage installed Aug. 10. b Aug. 11-31. c Sept. 1-10. d Sept. 1-9. CLIMATE. 25 Daily precipitation, in inches, at stations in Seward Peninsula, 1906 to 1910, inclusive- Continued, Day. No- vem- ber, 1908. De- cem- ber. Janu- uary, 1909. Feb- ruary. March. April. May. June. Nome. Nome. Can- dle. Nome. Iron Creek. Can- dle. Nome. Black Point. 1 0.04 .01 .01 2 6.06 0.11 0.07 3 4 5 0.08 .12 .01 6 7 g o.ie .05 9 0.13 * * 10 11 .14 12 .04 13 0.06 "**09" .01 .03 .09 .03 .03 .03 Tr. 14 0.08 0.08 15 0.04 Tr. 16 .11 .05 17 18 .03 * 19 20 .07 0.05 21 .15 22 Tr. 23 .i7 .07 24 .08 Tr. 25 .10 03 26 .02 27 .02 .03 .18 .57 .07 28 .13 29 Tr. .05 .17 .22 .08 .07 ■".■62' 75 30 ,01 31 Total.... Snowfall, in inches .26 3.5 .75 11.75 .37 3.0 .13 2.0 .21 2.75 .45 5.0 .28 Tr. .15 Tr. .26 Tr. .07 Tr. .88 1.06 June, 1909, con. July. August. Day. Iron Creek. Candle. Nome .a Black Point. Ophir. Candle. Nome. Black Point. Ophir. Dahl. Candle. 1 Tr. 2 1 Tr. 3 0.33 .28 0.42 .22 Tr. 0.40 0.10 .01 4 0.36 5 Tr. 0.03 Tr. 02 6 Tr. 7 , . .09 .40 .58 '"".'65" .04 Tr 8 0.42 0.00 .16 0.11 .42 .11 .38 .13 .07 .72 .22 9 ... Tr. 40 10 .05 .11 11 12 .18 .05 .12 .24 .03 .02 .10 13 Tr. Tr. .03 .20 14 15 Tr. .08 .04 • The daily values for July at Nome are incomplete, but the monthly total is correct. ^6 SUEFACE WATER SUPPLY OP SEWARD PENINSULA. Daily precipitation, in inches, at stations in Seward Peninsula, 1906 to 1910, inclusive — Continued, June, 1909, con. July. August. Day. Iron Creek. Candle. Nome. Black Point. Ophlr. Candle. Nome. Black Point. Ophir. Dahl. Candle. 16 0.32 '""6.02" .02 0.03 .02 0.04 17 18 19 20 .03 21 22 . . 0.02 Tr. 23 0.02 .05 24. ... 25 26 27 .04 .07 ;;;;;;; .07 0.11 .05 .08 0.12 .02 0.01 28 .12 05 .04 05 29 30 . . .02 31 Tr. Total. a. 06 .84 .82 .64 0.00 .81 1.66 1.87 1.81 .21 .83 September, 1909. October. November. December. Day. Nome. Black Point. Grand Cen- tral. Ophir. Dahl. Can- dle. Nome. Can- dle. Nome. Ophir. Nome. Ophir. 1 2 :::::::i : ::: 0.08 3 Tr. 4 0.04 .04 0.02 .14 0.01 .14 0.01 .13 5 Tr. 0.18 .09 6. .. 7 0.05 .18 .10 8 9 . Tr. .15 ■ 10 11 .26 12 ' 0.01 13::::::::::::;: .11 .05 Tr. .17 .02 .10 0.49 .05 0.12 .11 .07 .07 .05 .06 14 15 .17 16 .28 .06 C.14 C.38 .03 17 * 18 . . . . ... .01 Tr. .15 19 20 .... 21 .05 .02 .16 .15 .24 Tr. 22 .02 Tr. .01 .02 .11 .24 .39 .28 .10 23 24. . .14 .23 25 .06 .31 . .15 26 27 28 Tr. 29 .08 Tr. .20 30 .08 31 Total.... Snowfall, in inches .96 d.72 «.27 1.26 .09 .47 1.45 1.5 .15 1 1.16 14 2.04 29 1.22 16 2.58 27 o Accuracy of record doubtful. b Daily values not available. c Water equivalent of snow. d Total, September 1-21. e Total, September 1-14. CLIMATE. t1 Daily precipitation, in inches, at stations in Seward Peninsula, 1906 to 1910, inclusive- Continued. January, 1910. February. March. April. May. Day. Nome. Ophir. Dahl. Nome. Ophir. (a) Nome. Ophir. (a) Nome. Ophir. (a) Nome. Ophir. (a) Dahl. 1 O.U 2 :::::::r:;::: 8 ... I * 4 0.22 0.65 5 0.12 6 .07 7 .03 .06 g 9 . .. .06 .. . 10 0.23 Tr. 1.00 11 .09 .15 .48 12 13 14 .16 .32 15 .. . 1 16 Tr. .09 0.11 Tr. .16 .13 .06 17 .02 18 .03 .09 Tr. 19 20 .62 .12 ..." 21 .19 .07 .07 .10 22 23 .11 24 25 .27 26 ... 27 28 29 .11 .12 04 30 . 31 Total.... Snowfall, in inches .94 13 2.05 27 2.19 .32 3 0.29 3.2 .23 2.4 0.35 5.8 .49 5 0.55 7 1.03 0.40 1.06 Day. June, 1910. July. August. September. Octo- ber. No- vem- ber. De- cem- ber.a Nome. Can- dle. Nome. Black Point. Can- dle. Nome. Black Point. Nome. Black Point. Can- dle. Nome. 1 0.30 0.15 0.30 .08 0.47 .34 0.32 0.06 .06 .06 2 . . 0.05 0.31 0.04 .01 3 .15 4 5 Tr. .09 .04 .04 .05 .(M .06 .07 .20 .03 .03 .22 .05 .02 .14 04 1.14 .28 .68 .02 1.87 1.90 .85 .03 .10 6 7 .03 .15 .04 8 0.17 .13 .30 .02 .01 .08 .22 9 .19 .07 .04 Tr. .04 10 Tr. 0.25 11 .02 12 .05 .04 .04 .03 .03 .21 .57 .18 .08 .05 .16 .21 .40 .66 .08 .09 .21 13 .02 .04 14 Tr. .06 16 16 .21 .35 Tr. .22 Tr. .17 17 .25 .15 .10 .20 .10 18 .39 .09 .23 19 20 1.06 .80 .05 a Daily values not available. 28 SUBFACE WATER SUPPLY OE SEWARD PENINSULA. Dmly 'precipitation, in inches, at stations in Seward Peninsula, 1906 to 1910, inclusive — Continued. Day. June, 1910. July. August. September. Octo- ber. No- vem- ber. De- cem- ber. Nome. Can- dle. Nome. Black Point. Can- dle. Nome. Black Point. Nome. Black Point. Can- dle. Nome. 21 ^ 0.02 0.04 0.10 .10 0.37 .26 .62 .16 .07 .02 0.60 1.04 1.52 .51 .30 .10 Tr. 0.25 .05 .15 .02 22 0.07 .13 .37 .06 0.05 .28 .16 23 .38 0.11 24 0.04 Tr. 0.06 .12 .24 25 .... .15 .12 .06 .14 .08 .27 .01 26 0.04 .08 .07 27 .14 .39 .31 .28 .02 .03 28 29 .13 30 .04 .13 .07 .05 .05 31 .04 Total.. Snowfall, in 1.59 1.20 3.57 0.79 1.68 2.61 2.79 4.06 9.58 1.23 1.08 .99 10.8 0.56 4.8 a Total for July 22-31. Note.— Monthly totals for Ophir from June to September may be found in the table below, giving a summary of monthly precipitation. Summary of monthly precipitation, in inches, at stations in Seward Peninsula, 1906- 1910, inclusive. Station and year. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. For period. Nome: 1906 2.38 2.08 2.10 .82 3.57 2.50 2.68 2.92 1.66 2.61 1.02 1.41 .52 .96 4.06 0.93 .16 1.13 1.45 1.08 0.32 .06 .26 1.16 .99 1.91 .30 .75 1.22 .56 9.06 1907 1908 1909 1910 2.64 .43 .37 .94 1.46 .76 .13 .32 3.37 1.19 .21 .23 0.10 .02 .45 .49 1.12 .19 .15 1.03 1.31 .90 .88 1.59 16.69 11.17 9.46 17.47 Mean 1.10 .67 1.25 .26 .62 1.17 2.19 2.47 1.59 .95 .56 .95 13.78 Ophir: 1906 3.57 00 3.68 1.91 1.81 2.28 5 48 1909 i.26 2.36 al.50 2.04 2.58 9.19 1910 2.05 .29 .35 .55 .40 b.lQ 12.12 Mean 2.42 2.00 Black Point: 1907 2.62 .57 1.06 1.94 2.30 .64 d.79 2.85 3.42 1.87 2.79 3.26 .63 c 72 9.58 10.67 1908 .40 7.32 1909 4.29 1910 13.16 Mean 1.42 dl.63 2.73 e4.49 Grand Central: 1S07 3.61 4 02 7.19 fi 21 5.06 .72 15. 86 1908 10.95 Mean 3.82 6.70 2.89 13.41 Salmon T/ake: 1906 4.92 1.79 3.33 3.65 3.26 2.26 11.51 1907 . . 1 2.31 10.01 1 3.36 3.49 2.76 ' * 1 i Iron Creek: 1908 1.67 1.27 .30 3.24 1909 .26 a. 06 .32 Shelton: 1907 .71 1.32 1.33 .47 2.51 1908 .44 1.76 a Accuracy of records doubtful. b Estimated by the observer. c Sept. 1-21, inclusive. d July 22-31, inclusive. e Partial months not included in mean. CLIMATE. 29 Summary of monthly precipitation, in inches, at stations in Seward Peninsula, 1906- 1910, inclusive — Continued. Station and year. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. For period. Dahl: 1909 0.21 0.09 0.30 1910 2.19 1.06 Taylor: 1907 0.66 .68 .96 1.11 1.17 0.23 2.79 1908 2.02 Mean .67 1.04 Budd Creek: 1908 .69 1.87 2.56 1 Candle: 1908 6.50 .83 (1.16) C.20 .47 1.23 1909 (.20) (0.07) (0.11) 0.28 .07 0.84 1.20 .81 1.68 0.15 (0.63) (0.66) 5.12 1910 5.27 Mean, 1909-10 1.02 1.24 (1.00) .85 a Sept. 1-10, inclusive. & Aug. 11-31, inclusive. c Sept. 1-9, inclusive. Note. — Values in parentheses are estimated by a comparison with the Nome data. An analysis of stream-flow records makes possible a determination of the amount of water which flows from a basin in which a gaging station has been maintained. When this run-off is computed as depth in inches on the drainage area, it is directly comparable with precipi- tation records obtained in the same area, if the loss due to evaporation is taken into consideration. The discharge of the streams in Seward Peninsula during the period between the break-up and the freeze-up represents practically the total flow for the year, as the ice prevailing throughout the wlater permits only a small underflow for that period. The following table summarizes the run-off of representative streams in the peninsula for the years covered by records. It is of value as an indirect index of the precipitation and serves to supplement the meager rainfall data available. Summary of monthly run -Off/ 'n inches, at principal gaging stations in Seward Peninsula^ 1906 to 1910, inclusive. Station and year. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. For period. Ophir Creek, at Canyon-ditch intake: 1909 0.83 1.97 0.85 1.38 0.60 0.6S 2 28 Pargon River,b at ditch in- take: 1909 4 03 Nome River, at Miocene in- take: ft 1906 4.25 5.11 1.19 2.16 3.88 2.59 3.36 1.19 4.88 4.91 dl.SO ,92 13 01 ]907 12 61 19QS cl.62 «3.93 7.47 1909 8 20 Mean 3.18 2.75 /3.57 _ .^ a Sept. 1 to 25, inclusive. h Natural discharge. c June 20 to 30, inclusive, d Sept. 1 to 22, inclusive. e June 15 to -SO, inclusive. / Partial months not included in mean. 30 SUEFACE WATEK SUPPLY OF SEWARD PENIKSULA. Summary of monthly run-off, in inches, at 'principal gaging stations in Seward Peninsula^ 1906 to 1910, inclusive — Continued. station and year. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. For period. Nome River, at Pioneer in- take: a 1908 1.21 2.93 9.57 3.80 1.20 5.45 61.45 .94 9.32 6.46 1909 C5.91 11.03 10.98 1910 35.37 Mean 4.57 3.48 d5.13 Grand Central River below the forks: ]906 e2.00 14.64 4.95 7.98 26.40 6.73 9.71 4.18 12.68 9.25 4.02 /1. 70 32.62 1908 . 18.68 1909 13.86 1910 ff '111. 97 51.05 Mean 13.49 8.32 d6.64 Kruzgamepa River, at out- let of Salmon Lake: 1906 1907 1908 1909 1910 (1. 10) ( .96) ( .82) ( .82) ( .69) (0.74) ( .74) ( .65) ( .62) ( .56) (0. 69) ( .69) ( .69) ( .55) ( .55) (0.57) ( .54) ( .54) ( .54) ( .54) 12.19 6.96 5.67 4.77 2.58 14.73 24.88 9.72 11.60 10.06 7.90 7.62 2.58 4.78 14.00 3.66 4.76 4.10 2.04 6.77 6.19 6.49 2.14 1.44 12. 97 (2.88) (2.06) LIO .96 2.64 (1.46) .80 (1.20) ( .89) .69 ( .82) .92 53.44 57.85 29.80 29.61 53.38 Mean ( .88) ( .66) ( .63) ( .57) 6.43 14.20 7.38 4.27 5.85 1.93 1.11 44.83 Kuzitrin River, at Lanes Landing: i 1908 2.26 2.71 3.84 .27 .44 1.81 .40 .24 1.24 .24 .20 1.75 3.17 1909 71.72 41.53 5.31 1910 1.09 10.26 Mean 2.94 .84 .63 .73 Eougarok River , at H m estake- ditch intake:o 1907 m.lS .15 .24 .60 .14 .32 «1.34 O.09 ?.08 2.12 1908 .38 1909 P. 61 1.25 Mean d.20 .35 .65 .15 Kougarok River, above Coarse Gold Creek: 1907 .17 .14 .29 nl.l4 r.07 1.96 1908 .36 1909 P. 41 .70 Mean .20 .40 G oodhope River, below Esperanza Creek: 1909 «.]0 .23 .20 .12 .14 «.07 .06 .52 Kiwalik River, below Candle Creek: 1909 .40 Note. — Values in parentheses are estimated. c Natural discharge. b Sept. 1 to 22, inclusive, c June 10 to 30, inclusive. d Partial months not included in mean. e June 24 to 30, inclusive. /Sept. 1 to 21, inclusive. g Estimated from discharge of Kruzgamepa River at outlet of Salmon Lake. • A June 15 to 30, inclusive. » Lanes Landing and Shelton are identical, i May 19 to 31, inclusive. k May 22 to 31, inclusive. I Oct. 1 to 8, inclusive. ■m July 15 to 31, inclusive, m Sept. 1 to 20, inclusive. o Sept. 1 to 10, inclusive. p June 20 to 30, inclusive. « Sept. 1 to 16, inclusive. r Sept. 1 to 12, inclusive. « Sept I to 26, inclusive. CLIMATE. 31 From the foregoing observations on the precipitation certain facts of significance have been determined One of the most notable fea- tures is that the larger part of the precipitation at all stations occurs during the summer, from the last of May to the middle of October. Various estimates show that from two-thirds to three-fourths or more of the total yearly precipitation occurs during these months. For this reason the summer visitor gains the impression that the rainfall in this region is much greater than it actually is. The average yearly precipitation at Nome since 1906 is 13.78 inches and the average yearly run-off of Kruzgamepa River at the outlet of Salmon Lake for 1906-1910 is 44.83 inches. The greater part of the drainage area of Kruzgamepa River lies within the Kig- luaik Mountains, and it is safe to assume that the average yearly precipitation in the mountains for this same period exceeds 50 inches. The partly estimated precipitation at Candle for 1909 of 5.12 inches is a little over 50 per cent of that at Nome and only 17 per cent of the run-off of Kruzgamepa River for that year. Totals for periods during which rainfall records were kept at the several stations have been compared with the totals for the same periods at Nome. The following list gives the average relation so determined in approximate percentages of the precipitation at Nome : Ophir, slightly greater. Black Point, about 130 per cent. Grand Central, about 220 per cent. Salmon Lake, about 160 per cent. Shelton, about 50 per cent. Taylor, about 40 per cent. Candle, about 50 per cent. A similar study of the run-off can be made only at those stations where the records extend from the break-up to the freeze-up. The average yearly run-off of Kruzgamepa River at the outlet of Salmon Lake for 1906-1910 is about 320 per cent and that of Kuzitrin River at Lanes Landing for 1909-10 is between 55 and 60 per cent of the average yearly precipitation at Nome for similar periods. The latter percentage is probably small, because it does not include the winter flow of the Kuzitrin, which, however, represents only a small percentage of the total flow. The winter flow of the Kruzgamepa was estimated. It is interesting to note that the run-oft' of Kuzitrin River at Lanes Landing or Shelton is a greater percentage of the precipitation at Nome than that given above for the rainfall station at the same place. This discrepancy can be accounted for by the fact that the precipitation is heavier in the higher areas within the drainage basiii than at Shelton. The whole region is subject to 32 SUKFACE WATEE SUPPLY OF SEWAED PENINSULA. local showers and storms, niany of which are heavy in one valley and not felt in the next, and the precipitation from a general storm may be very unequally distributed. The percentages given above may therefore be considerably in error, especially as many of them were determined from records covering short periods. The lack of uniformity in the amount of precipitation falling in different parts of the peninsula is probably due to the fact that southerly winds bring the heaviest rains and lose most of their moisture in passing over the mountains. In the summer of 1907 76 per cent of the rainfall at Grand Central was accompanied by winds from the southern quadrant, whereas only 40 per cent of the rainfall at Taylor was accompanied by winds from the same quadrant. The percentages for the other stations range between these extremes. The precipitation and run-off data show that 1906, 1907, and 1910 were years of fairly good water supply and that 1908 and 1909 were years of drought. The total precipitation at Nome in 1909, 9.46 inches, is 69 per cent of the average for the period covered by records and only 54 per cent of the maximum of 17.47 inches which occurred in 1910. The same comparison applied to the run-off data of Kruz- gamepa River for the same years gives percentages of 66 and 55 respectively. The maximum yearly run-off of the river from 1906 to 1910, however, was 57.85 inches, in 1907. DESCRIPTIVE GEOLOGY. By Philip S. Smith. The many different rocks and deposits in Seward Peninsula may be grouped into three main divisions which, for convenience, will be called the sedimentary rocks, the igneous rocks, and the uncon- solidated deposits. Each division is composed of several different members; for example, the sedimentary rocks consist of metamorphic and nonmetamorphic rocks, and these may be further subdivided, according to their lithoiogy or structure, into schists, limestones, slates, sandstones, and conglomerates. It is not intended, however, to present in this paper, a detailed geologic report on Seward Penin- sula, and the reader who desires that information should consult the publications of the United States Geological Survey primarily devoted to that subject.^ 1 The following are of greatest general importance, though the yearly "progress reports" are of value: Collier, A. J., Hess, F. L., Smith, P. S., and Brooks, A. H., The gold placers of parts of Seward Peninsula, Alaska: Bull. XJ. S. Geol. Survey No. 328, 1908, 343 pp. Moffit, F. H., The Fairhaven gold placers, Seward Peninsula, Alaska: Bull. U. S. Geol. Survey No. 247, 1905, 85 pp. Smith, P. S., Geology and mineral resources of the Solomon and Casadepaga quadrangles, Alaska: Bull. U. S. Geol. Survey No. 433, 1910, 234 pp. Smith, P. S., and Eakin, H. M., A geologic reconnaissance in southeastern Seward Peninsula and the Norton Bay-Nulato region, Alaska: B-ull. XJ. S. (j^qL Survey No. 449, 1911, 14^ pp. U. S. G GEORGE 1 ER-SUPPLY PAPER 314 PLATE IV 161° ^V/ Q^d c/r^y^— -J \f\Sel^^^ ^"^ jscholtz. Bevy \ ) 66° ji^^Qud /g^ k o 66 2? V_^/ 1 CapePr of Wa! k ^^!;V:W_ F^Ci/^ W^^\i " 65 UlJ%^ o 65 ^XjT vy^^m ^^^fo^;^ ? v Ks .>^' / jbe/ Qud 10 i;^-^^^^— / \ [^= \i. 161° Tipiled and arrangec i by F »hilip S. Sm th LEGEND SEDIMENTARY ROCKS Qud Unconsolidated deposits <2 ^ Ks Cretaceous sediments including sorae Tertiary Chiefly Paleozoic limestones sch 3 UndiflFerentiated schists "-% Kigluaik group IGNEOUS ROCKS be Late basic effusives Granitic intrasives so pc< Early basic effusives Gold placer Coal mine U. S. GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR WATER-SUPPLY PAPER 314 PLATE LEGEND SEDIMENTARY ROCKS GEOLOGIC MAP OF SEWARD PENINSULA, ALASKA DESCKIPTIVE GEOLOGY. 33 SEDIMENTARY HOCKS The general distribution of the rocks that have been mapped in Seward Peninsula is shown in Plate IV. On this map the sedimen- tary rocks have been grouped in four divisions. These are, com- mencing with the oldest, the Kigluaik group, the undifferentiated schists, the Paleozoic limestones, and the Cretaceous and Tertiary conglomerates and sandstones. The Kigluaik group consists of gneiss overlain by a heavy lime- stone, which, in turn, is overlain by biotitic and graphitic schists. It is most extensively developed in the Kigluaik and Bendeleben mountains, but some of the areas mapped as undifferentiated schist may include also members of this group. The sedimentary rocks of which it is composed are cut by granitic and basic dikes and stocks. The rocks show a complex history, inasmuch as an unconformity has been recognized between the lower and upper members. The lower limit of the Kigluaik is not known, and the group probably repre- sents the oldest sedimentary rocks exposed in the region. No defi- nite age has been assigned to the group except that it is undoubtedly pre-Ordovician. It is possible that it may even be pre-Cambrian. The undifferentiated schists, as their name implies, are meta- morphic rocks of complex origin, the stratigraphy of which has not been adequately determined and which, therefore, probably contain representatives of both higher and lower horizons. They are mainly quartzose chloritic schists, but include some subordinate limestones and some undistinguishable sheared igneous rocks. They occupy a greater area than any other of the rock divisions. The dominant structure is cleavage, so that m places precise determination of the attitude of the rocks is impossible. The topographic forms produced by the schists are not striking except where they stand at the sum- mits of ridges, on which they form remarkable pinnacles. Although these schists contain diverse members, it is believed that the larger part of them are older than the next higher division, and they may therefore be regarded as in part equivalent to the Kigluaik group. Moffit,^ who has made the most detailed study of the undif- ferentiated rocks south of the Kigluaik Mountains, has stated that the schists at the head of Nome and Sinuk rivers probably overlie the Kigluaik group unconformably. If this is true it may mean that these rocks too are pre-Cambrian. Although there is no definite way of determining the lower limit of these rocks it seems probable that the schists as a whole are pre-Ordovician. The gold of most of the placers of Seward Peninsula has been derived from these schists. 1 Moffitt, F, H., The Nome region: Bull. U. S. Geol. Survey No. 314, 1907, pp. 128-129. 63851°— wsp 314—13 3 34 SUEFACE WATEK SUPPLY OF SEWAED PENINSULA. In the western part of the peninsula, forming an area of 1,400 square miles, is a thick series of gray limestones which seem in places to overlie conformably schists belonging to the group of undifferen- tiated rocks. The structure of this area is complex, and the strati- graphy has not been determined. Collier ^ originally called this series of gray rocks the Port Clarence limestone and assigned it to Ordovician and Silurian time. Subsequent studies, however, have shown that these rocks have a much greater range in time than was at first supposed, and in the typical Port Clarence region late Cam- brian fossils have been reported from them by Kindle. Correlations by other observers in remote portions of the field have referred to this series certain limestones of Devonian and Carboniferous age, and these inexact correlations indicate that more field work will be neces- sary to map satisfactorily the various members of this division. In the present report it has been necessary to group these diverse strata together under the head ^'Paleozoic limestones.'' Although this grouping obscures in a measure the precise geology of the region it serves to bring lithologically similar rocks together, and it also, in a broad way, permits the generalization that the heavy limestones, taken as a whole, lie above the schists, in general unconformably. The following summary of the general character of the limestone in the western part of the peninsula was prepared by Knopf: ^ Here it comprises a thick volume of thin-bedded limestones of dense texture, gen- erally unaffected by metamorphism. Four types of rock can be discriminated — an ash-gray variety, a dark lead-gray variety, magnesian and tremolitic phases, and an argillaceous banded variety. The first two are the commonest types and occur together in interstratified beds. The dark lead-gray limestone forms massive beds up to 6 feet thick, while the ash-gray variety, which is fine grained, like lithographic stone, is thin bedded and commonly breaks into thin slabs whose surfaces are covered with fucoid fragments. Some beds of fine-grained dolomite occur in the Port Clarence formation. Occasionally strata occur interbedded with the normal Port Clarence limestone which show numerous small prisms of tremolite in random orientation. This is the highest degree of metamorphism displayed by the formation except for purely local manifestations surrounding granitic intrusives. As a rule, where limestone forms the country rock much of the drainage is carried underground and consequently the amount of the available water is lessened. Here and there, however, near the base of the limestone, are springs which discharge an abnormal amount of water. Moonlight Springs, on Casadepaga River, form a strik- ing example. Furthermore, this limestone makes very bad ditching ground, and its distribution is therefore an important economic factor. Owing to its hardness the limestone is usually difiicult to excavate where it forms the bedrock of a placer deposit, and its » Collier, A. J., op. cit., p. 79. 2 Knopf, Adolph, Geology of the Seward Peninsula tin deposits, Alaska: Bull. U. S. Geol. Survey, No. 358, 1908, pp. 12-X3, DESCKIPTIVE GEOLOGY. 35 weathered surface is usually so irregular that the recovery of gold from it is costly and laborious. The next younger group of rocks belongs mainly to the Cretaceous system, though it may include some Tertiary sediments as well. The junction between the Cretaceous and the older rocks is really the eastern boundary of Seward Peninsula. East of that line the Cretaceous rocks extend practically without interruption beyond the mouth of the Koyukuk. West of the line several small areas, such as those east of the Tubutulik and on the Koyuk, mark infolded or infaulted blocks of the younger rocks. Although it is by no means proved, it is not unlikely that the two small coal areas on Kugruk and Sinuk rivers may be of the same age as this group, though they have formerly been provisionally correlated with the Tertiary. The typical Cretaceous sediments, though much folded and faulted, are unaffected by metamorphism. At the base of the section lies a heavy bedded conglomerate, called the Ungalik conglomerate, made up of pebbles of the metamorphic rocks, the granites, and the older effusives. Conformably upon the conglomerates lie the sandstones and shales which have been called in the eastern part of the region the Shaktolik group. ^ These strata are made up mainly of commi- nuted volcanic rocks and quartz. The two divisions of the Cretaceous together form a stratigraphic section many thousand feet thick. Although of considerable geologic interest, these rocks are of small importance in the present discussion, for they are not notably placer bearing and they are absent from the parts of Seward Peninsula where mining has been successfully carried on. IGNEOUS ROCKS. The igneous rocks of Seward Peninsula present great diversity of character, but in the present paper they have been classified in only three main subdivisions, namely, the granitic intrusives, the pre- Cretaceous effusives, and the late basic effusives. Another sub- division exists, made up of the greenstones and metamorphic schists of igneous origin, but owing to the small scale of the map and to the lack of specific information about the areal distribution of these sheared igneous rocks throughout the peninsula, this group has been included with the undifferentiated schists. So far no definite con- nection between these various igneous rocks and the production of auriferous deposits has been proved; in fact, placer deposits are notably absent from the areas of igneous rocks. 1 Smith, P. S., and Eakin, H. M., A geologic reconnaissance in southeastern Seward Peninsula and the Norton Bay-Nulato region, Alaska: Bull. U, S. Geol. Survey, No. 449, 1911, pp. 55-60. 36 SUKFACE WATEB SUPPLY OF SEWARD PENINSULA. Granitic intrusive rocks are particularly abundant in the Kigluaik- Bendeleben and the Darby mountains and in the divide be-tween Buck- land and Kiwalik rivers. In the Kigluaik-Bendeleben Range the rock is a true granite, light colored, even grained, and unsheared, and offers strong resistance to normal weathering. These intrusive rocks cut the metamorphic schists and the Paleozoic limestones, but they form pebbles in the Ungalik conglomerate at the base of the Cretaceous system, so that their age is probably Mesozoic. The granites occur mainly as batholiths, but also, in the vicinity of the larger masses, form numerous dikes parallel to the secondary structure of the meta- morphic rocks. In the Darby Mountains the granitic rocks are diorites and granites. In composition the diorite ranges from a normal amphibole-plagio- clase rock to one containing quartz and orthoclase in addition to the usual constituents. The plagioclase is apparently about midway in the albite-anorthite series. Accessory apatite, titanite, muscovite, and metallic minerals in small amounts were noted in several speci- mens that were studied microscopically. The granites are of two distinct types— one with a marked porphyritic development, and the other with an even grain similar to the granite from the Kigluaik- Bendeleben Mountains. The porphyritic granite is characterized by a coarse-grained mass of quartz orthoclase and a little biotite, the grains averaging about 0.2 inch in diameter. Large orthoclase crystals averaging about an inch and a half in length are scattered abundantly through the rock. Some inclusions of diorite have been found in the porphyritic granite, but elsewhere granites are included in diorites, so that an intricate and complex history is indicated for the period of intrusive activity. In the divide between Buckland and Kiwalik rivers there is a series of andesites and associated rocks, unknown elsewhere in Seward Peninsula. These rocks have been designated on the map (PI. IV) ^ 'Early basic effusives." They are entirely unmetamorphosed, are cut by granites, and form pebbles in the Ungalik conglomerate, so that an approximate determination of their age is not dijfficult. These rocks have been described by Moffit ^ as follows : They are of a dark-gray or greenish color, and on an exposed surface have a spotted appearance due to the alteration of the feldspar phenocrysts. Both hornblende and pyroxene varieties were seen, the latter containing considerable olivine in addition to pyroxene, and showing the secondary mineral, iddingsite. Alteration of pyroxene to hornblende was also observed. The feldspar is a basic variety, labradorite or some- times anorthite, giving as alteration products chlorite and epidote. Andesite breccias were found at various localities. Effusive rocks of later geologic age are found at many places. Probably not all these flows are contemporaneous, but in a broad way 1 Moffit, F. H., The Fairhaven gold placers, Seward Peninsula, Alaska: Bull. U. S. Greol. Survey No. 247, 1905, p. 31. DESCKEPTTVE GEOLOGY. 37 it is believed tbat they mark essentially one period of volcanism. Thus, though many years elapsed between successive flows, there is strong reason for correlating them and for regarding them as sjTQchronous in a geologic sense. Although practically all these rocks are surface flows, there are, of course, here and there dikes by which the flows were fed. All these rocks are characteristically olivine basalts having a vesicular structure. The effusive rocks occur mainly in the eastern part of the peninsula and occupy an area of over 1,000 square miles. So recent are some of the flows that the surface is practically undissected, and the tongues of lava, as in the Noxapaga and Kuzitrin basins, still preserve the form they acquired as they flowed over the country. The region around Imuruk Lake, locaUy known as the "goose pastures,'' shows typical examples of these recent flows. UNCONSOLIDATED DEPOSITS. Gravels were deposited on the sea floor and on the land surface over a long period that began before the appearance of the volcanic effusives and continued for some time after the eruptions had ceased. These deposits have here been grouped together under the term ^^unconsolidated deposits." Their accumulation took place under conditions that varied greatly owing to the diversity of the physical features of the region from which they were derived and of the surface on which they were laid down. Some of the gravels were deposited on the sea floor and were modeled into form by waves and ocean cur- rents. In other places the land waste was transported and laid down by streams. In still other places vaUey glaciers eroded their beds, transported fragments, and on melting left deposits characteristic of ice action. Some deposits have been worked upon by two or more agencies, and therefore show complex relations. The unconsolidated deposits are presumably mainly of Pleistocene and Recent age. Some Tertiary fossils from the coastal plain at Nome have been determined by Dall, and some of the ancient stream gravels may also belong to the Tertiary period. The volume of the Tertiary deposits is undoubtedly much less than that of the Quaternary unconsolidated deposits. Some of the deposits, especially in the surface portions of the coastal plain, consist of fine-grained bluish-gray muck, which con- tains a considerable amount of vegetal material and numerous beds and lenses of clear ice. Where the turf overlying the muck is re- moved the ice thaws rapidly and the material caves. Deposits of this type are very widespread and offer one of the greatest difficul- ties to ditch construction. (See p. 258.) In places this muck layer is only a few inches thick, but in others it has a measured thickness 38 SUEFACE WATER SUPPLY OF SEWAED PENIlSrSULA. of more than- 50 feet. Its origin is complex, and apparently it has been formed under different conditions in different places, so that no general statement can be made as to its mode of formation. The unconsolidated deposits are most important from the stand- point of the placer miner, and as the utilization of the water supply IS most closely bound up with placer operations more specific atten- tion will be paid to this type of deposit in the following pages. The various forms in which the unconsolidated deposits are found will be more fully discussed in the section on types of placers (pp. 38-51), and the physical condition of the gravels will be described in greater detail in the sections on mining methods (pp. 269-303), and on ditch construction (pp. 255-269). A more complete description of this important class of deposits has already been published by Collier and others.^ Many if not most of the unconsolidated deposits are permanently frozen and present conditions not found in more temperate latitudes. No satisfactory explanation has yet been advanced to account for the distribution of the permanent frost, for patches of thawed and frozen ground are associated in relations so complex that it is im- possible to frame a theory that will account for all the known facts. The presence or absence of permanently frozen material has an important effect in determining the method of mining the uncon- solidated deposits that contain placers ^ GOLD PINCERS. By Philip S. Smith. NATURE AND ORIGIN. This report was not prepared primarily for technical readers, and certain parts of it have been written especially for those unfamiliar with placer mining. To give an elementary conception of placers and placer mining, it may be stated that a placer is a deposit of disintegrated rock fragments more or less concentrated by various geologic processes, containing economically valuable minerals. The valuable minerals are separated from the worthless ones by taking advantage of some physical property peculiar to the material to be saved. Placers have been formed under a variety of conditions and con- sequently have different characters and relations to the present topography. A number of different classifications based on some particular features might be made, but in the present paper a classi- fication based mainly on the mode of origin and therefore indicating the topographic expression of the deposit will be adopted. Accord- ing to this scheme the Seward Peninsula placers may be divided into 1 Collier, A. J., and others, The gold placers of parts of Seward Peninsula, Alaska: Bull. U, S. Geol. Survey No. 328, pp. 85-94. GOLD PLACEKS. 39 two main classes, residual and water-sorted, of which the latter is more important. There are gradations between the different types, and it might be impossible to place in their appropriate classes all known examples, but such difficulty is practically unavoidable in any systematic treatment. RESIDUAL PLACERS. Eesidual placers are those that have formed near a mineralized deposit practically without transportation. Ordinary weathering causes rocks to crumble and disintegrate, so that detritus collects at the bases of ledges. If the rock contains valuable minerals that are unaffected by solution and the other chemical processes connected with weathering the deposits thus formed may be of economic value. In the Council region, on one of the gulches tributary to Crooked Creek, a residual placer of this sort has been formed on the slope below a vein of auriferous quartz. The placers near the head of Bering Gulch in the Bluestone region may also belong to this class, although too little is laiown about them to permit final statement as to their character. As there has been little transportation of residual deposits except the downhill creep of the material, little sorting has been effected, and consequently the gold content of the residual placer is usually only a little greater than that in the parent ledge from which it was derived, unless the process has been continued for a very long time. Placers of this type are therefore not widely distributed, are generally small, and, unless the rocks from which the valuable minerals were derived are very rich or weathering has been long effective, are not of sufficiently high tenor to warrant extensive development. Further- more, most of these deposits occur at elevations so high above the drainage lines of the region that the cost of mining them is great. WATER-SORTED PLACERS. The more important placers are those in which water has effected a concentration, whereby the lighter material has been transported farther than the heavier, more valuable minerals. These placers may be divided into two main classes — those formed by flowing water, as in rivers, and those formed by shore action along the bor- ders of the sea or large fresh-water lakes. For convenience in de- scription the former will be called stream placers and the latter beach placers. In general, the stream placers are of fresh-water origin, and most of the beach placers were formed under marine conditions, though intermediate phases are not uncommon. 40 SUKFACE WATEE SUPPLY OF SEWARD PENINSULA. STREAM PLACERS. Stream placers have heretofore been the raain source of the gold of Seward Peninsula, and they will undoubtedly long continue to yield a large amount of the production. Classified by age and con- sequently by relative topographic position these deposits may be divided into modern and ancient. Obviously with terms so elastic the same deposit might be placed in different categories, the placing depending on the interpretation of the term modern. In this paper those placers that are practically in process of formation by the pres- ent streams or are so closely related to them that theii' origin is imme- diately connected with those streams are called modern, and the others are called ancient. In most of the typical modern stream placers the auriferous gravels are not more than 5 to 10 feet thick. In places the workable deposits extend almost uninterruptedly along a creek, though with considerable range in tenor. Elsewhere the profitable placer or pay streak is dis- continuous, rich spots alternating with poor ones. The gold in these placers, although it occurs in all portions of the deposit, is usually most abundant in the lower part. Wliere this bottom concentration has taken place on bedrock the particles of gold penetrate to a greater or less extent along the cracks and crevices, so that in places several feet of the rock floor must be carefully treated in order to recover the valuable minerals. At other places a clay layer just above the bed- rock served as a floor on which concentration took place. The amount of placer gold on and in the bedrock is much less in such placers than in those where the clay is absent. In some deposits clay layers at intervals above the hard rock have served as floors on which gold has accumulated, and these are generally spoken of as '^ false bedrock." The gravels of which the modern stream placers are composed are mainly of local derivation and have shapes determined by the water- sorting agency by which they have been formed. The character of the material over which the stream flows has, of course, a marked effect upon the resulting placer. In some places the existing streams flow on disintegrated bedrock, in others the rock is hard and prac- tically unweathered, and in stiU others the present streams are flow- ing on old gravel deposits. Most of the small gulches and small side valleys which contain placers exemplify the first two conditions, but many of the larger rivers and the streams flowing across the coastal plain are carving their valleys in older gravel deposits, which, having been subjected to two or more processes, have features that indicate their more complex history. The particular type of modern stream placer that has received the specific name '^bar placer" is sioadlar in most respects to an ordinary stream placer, except that, as its name implies, it is confined to the bars. As a result the auriferous gravels are rather thin, and because GOLD PLAOEES, 41 of the sorting of the gravels during the periods of high water the surface portion is usually the richest. Practi- cally the bar placers are sHght reconcentrations of the upper part of normal stream placers. Examples of this type may be found throughout Seward Pen- insula. It should be noted that the ordinary stream placer may be made up of a great number of bars as the stream shifts its course, at one time building up and at another time cutting down. Bar placers grade so directly into stream placers that a differentiation would require greater refine- ment than is desirable in this report. As is well known, the surface of the earth is subject to move- ments whereby relative uplift or depression is effected. Fur- thermore, changes in climate may cause the streams to lose or gain transporting efficiency. These and similar causes pro- duce changes in the drainage lines whereby the streams are forced to cut new valleys or to fill up their former ones and take new courses. Traces of the earlier courses may be pre- served as old river beds on the hillsides or as filled channels far below the level of the present drainage lines. If the gravels of these now vanished streams contain valuable minerals they may form workable deposits. The ancient stream placers on the hillsides are commonly called tinctive name for the ancient deep bench placers, but there is no dis- placers. Figure 2 shews an ideal- 4^ SUEFACE WATEE SUPPLY OF SEWAED PENINSULA. ized cross section of a valley in which the various types of placers so far noted are diagrammatically represented. Bench placers of this type are formed of material similar in most respects to the modern stream gravels. Owing to the long time that they have been subjected to weathering, however, the pebbles are more decomposed, and the deposits may be more or less covered with material that has crept down the slopes. Some of the bench placers PAY STREAKS. 3000 feet Figure 3.— Sketch map and profile of high bench gravels south of King Mountain. indicate a simple history of only one period of formation, as, for instance, the upper bench placer shown near the left margin in figure 2. Others, however, show a complex history in their mode of forma- tion, as, for example, the bench placer illustrated in the right-hand portion of the same diagram. These conditions are not ideal, but they may be observed in some of the productive placer mines. For instance, near the head of Dexter Creek shafts and underground work ings have disclosed conditions represented in figure 3. As is shown GOLD PLACEES. 43 in the cross section, a body of bench gravels 250 feet deep was dis- covered, in places showing a distinct stream-channel cross section. So long ago, however, was this deposit formed that it is now more than 500 feet above the sea, and the ancient drainage lines have been so obliterated that a reconstruction of the topography is almost impossible. Bench placers are usually classified mainly according to topo- graphic form or position. There are, according to Collier,^ terrace benches, spur benches, pocket benches, and high benches. Some hillside placers are examples of bench placers, although others belong to the class of residual placers. The stream-deposited hillside placers are distinguished from other ancient bench placers because they have lost their topographic expression through the downhill creep of ma- terial subsequent to their formation. Each of these different kinds of bench deposit is represented by actual examples in the Seward Peninsula placer camps. Bench placers have been explored especially in the Nome, Council, and Candle regions, but are also important in the Solomon-Casadepaga, Bluestone, and Kougarok regions. Certain stream bench deposits merge so closely into ancient shore deposits that no sharp line of separation can be drawn. Some distinct bench deposits are due to shore conditions, and these can be dis- tinguished from the stream benches by their topographic expression, by the arrangement and character of the material of which they are composed, and some of them by the fossils they contain. Certain broad gravel deposits that stand at some elevation above the present streams show both fluviatile and shore features. Such deposits have been called gravel-plain placers. The deposits which show clearly that the dominant action producing the gravel plain has been other than fluviatile are treated in a later section (pp. 48-51). There are, however, large areas in the central part of Seward Peninsula where the complete history of the gravel-plain deposits has not been deter- mined, but where from the evidence now at hand it seems probable that streams played the most important part in the deposition. As a rule these fresh-water gravel plains do not contain rich placer deposits, and though in the future they may become commercially important they do not at present contribute any notable amount to the gold production of the peninsula. The other group of ancient stream placers, which, instead of stand- ing above the level of the present drainage lines, as the benches do, lie below that level, have not received much attention, though exam- ples are by no means uncommon. Practically all the larger rivers of the peninsula flow in filled valleys of older streams. For example, in 1 Collier, A. J., and others, The gold placers of parts of Seward Peninsula, Alaska: Bull. U. S. Geol. Sur- vey No. 328, 1908, p. 143. 44 SURFACE WATEE SUPPLY OE SEWARD PENINSULA. the lower parts of Snake and Nome rivers the depth to bedrock is in places at least 50 feet below the river surface; on the Casadepaga holes 60 feet or more in depth have been sunk before reaching bed- rock; no hole has yet reached bedrock in the lower parts of Kruz- gamepa and Kuzitrin rivers, and in many parts of Fish and Niukluk rivers the depth to bedrock is more than 50 feet. Even more remark- able, however, is the deep drill hole that, starting at an elevation of about 200 feet above the sea opposite Council, was put down 250 feet before reaching bedrock. A hole on Penelope Creek, a tributary of the Casadepaga, was more than 90 feet deep, and the shaft on Alameda Creek, a tributary of the Kojruk, was started a little more than 100 feet above the sea and went down 190 feet without reaching bedrock. On Dahl Creek, in the Kougarok region, a hole 187 feet deep has been sunk within 50 feet of sea level without encountering bedrock. All these localities seem to have been originally ordinary stream valleys which were subsequently aggraded and then dissected by the existing streams. In places where conditions were favorable placer deposits were formed in these deep ancient stream courses, and with suitable machinery such deposits can be mined. The gold is usually in the lower part of the deposit, but, as in the modern stream placers where layers of clay occur, some concentration may be expected. Nearly all these ancient stream placers in Seward Peninsula, together with the overburden above them, are permanently frozen. It will be shown later that the presence or absence of frost is an important item in determining whether certain of these deposits can be worked and indicating what mining methods must be employed. It is evident that there is a close genetic similarity between these placers and the bench placers, for the former mark old valleys that have been depressed, whereas the latter mark old valleys that have been elevated. It is perfectly conceivable that a deep placer in one part of a drainage basin might be equivalent in time of formation with a bench in another part, although no such examples have been recog- nized in the region. It will be clear, then, that no sharp line of differentiation can be drawn between the placers in these apparently antithetical positions with respect to the present streams. BEACH PLACERS. The main difference between stream placers and beach placers is due to the different agencies involved in the production of the two types. A stream placer has its long axis down the slope, parallel with the stream, whereas a beach placer is practically horizontal and extends parallel with the margin of the sea or lake in which it was formed. Like stream placers, the beach placers may be divided into two main groups, those now in process of formation and those pro- duced in the past. GOLD PLACERS. 45 In Seward Peninsula no placers formed along the shores of existing lakes are known and the only examples of modern beach placers occur along the seashore. In parts of the coast where the waves break on rocky headlands the rocks are disintegrated and beaches may be developed. None of these places, however, have afforded economically important placers. Instead, the places where much gold has been won from the present beaches are those where the sea is breaking against the unconsolidated deposits of the Coastal Plain or where there are strong alongshore currents. In this way a reconcentration of previously sorted material is effected, and the result is a particularly rich deposit. Figure 4 shows diagrammati- caUy an ideal section of the modern beach placers near Nome and illustrates the relation of these deposits to the sands, gravels, and clays of the Coastal Plain. Beach placers are, as a rule, confined to the narrow strip of coast affected by waves and alongshore currents. Where the sea is erod- FiGUEE 4.— Diagrammatic section of beach placers. ing outcrops of hard rock the gold is mainly in and on bedrock, but where bedrock is deeply buried, as at Nome, concentration has been effected mainly on clay layers. The richest modern beach concen- tration in Seward Peninsula extended for about 10 miles to the east and west of Nome, and the pay streak was from 6 inches to 3 feet thick. The gold was in small flakes, averaging, according to Brooks, from 70 to 80 colors to the cent.^ Most of the gold was bright and well worn. A considerable range in the tenor of the auriferous gravels was found as mining progressed, due, no doubt, to differences in the original conditions under which the Coastal Plain deposits were laid down and to their reassortment by the sea at the present time. Where concentration and reconcentration were most effective the richest placers were formed, and where these processes were rela- tively ineffective placers were absent. It is noteworthy, however, that traces of gold could be found practically everywhere along the beach and the question whether a certain area was minable was determined on purely commercial grounds. I Brooks, A. H., and others. Reconnaissances in the Cape Nome and Norton Bay regions, Alaska, in 1900: Special publication U. S. Geol, Survey, 1901, p. 87. 46 SUEFACE WATEK SUPPLY OF SEWAKD PENINSULA. In addition to the beach placer proper, Collier ^ has pointed out that — Some fine gold is also found in the gently sloping floor of the sea, but since this is probably derived from the beach, it is more disseminated and finer than the beach gold and can not at present be regarded as forming a workable placer. Stream bench and beach placer deposits High bench placer deposits Figure 5.— Sketch map of Nome region, showing distribution of placers. If, however, this material should subsequently be concentrated by waves and currents a valuable deposit might be produced. This 1 Collier, A. J., The gold placers of parts of Seward Peninsula, Alaska: Bull. U. S. Gaol. Survey No. 328, 1908, p. 145. GOLD PLACERS. 47 feature is, of course, of commercial importance only in the case of the ancient beaches the former seaward slope of which is now above sea level. In describing the history of mining developments (p. 271) reference is made to the ancient beaches near Nome. These are striking examples of beaches which since their formation have undergone a complex history v/hereby their attitude with respect to sea level has been materially changed. Two particularly well-marked ancient shore placers, whose positions are shown by figure 5, have been mined. The same figure also shows, on a larger scale than Plate I, the distribution of the placers of different types in the vicinity of Nome. These ancient beach placers differ in no genetic respect from the modern beach placers, but during the long time since their formation weathering and other geologic processes have combined to obliterate «j li il