The coal deposits in the vicinity of Eska Creek, a small tributary from the north to the Matanuska River, are a part of the Matanuska coal field. One of the two commercial coal-producing districts in Alaska, this field is in the southcentral part of the Territory, at the head of Cook Inlet. It is 170 miles from Seward, the ocean terminus of the Government-owned and -operated Alaska Railroad, and is served by a branch line of that railroad.

From abstract: The Chitina Valley and adjoining area form part of a rugged alpine region in the southeast corner of the main body of Alaska and include a portion of the Chugach Mountains and most of the southern half of the Wrangell Mountains, to the north. The Chitina River is an eastern branch of the Copper River and rises in ice fields and valley glaciers occupying most of the country near the international boundary north of Mount St. Elias. The adjoining area described in this report includes the Hanagita and Bremner River district and the westward continuation of the north side of the Chugach Mountains as far as Valdez Arm and Klutina Lake. In addition, the geology of the upper White River district is described because of its relation to that of the Chitina Valley.

From introduction: This report focuses on the placer geology of individual creeks; mining, history of the area, high terrace gravels, and the gold source of the Fortymile River area in Alaska.

From abstract: The Valdez Creek mining district was one of those visited in 1931 in connection with the study of the mineral resource of the region tributary to the Alaska Railroad. It is underlain by argillite, schist, tuff, tuffaceous conglomerate, limestone, and greenstone, listed in approximate stratigraphic order beginning with the youngest.

From abstract: The Mount Eielson district lies in south-central Alaska, on the north side of the Alaska Range, about 30 miles east of Mount McKinley. The most widely distributed rocks of the district include a thick series of thin-bedded limestone, calcareous shale, and graywacke of Paleozoic, probably Devonian, age. These sediments are cut by a mass of granodiorite which forms most of Mount Eielson and which was intruded probably in late Mesozoic time. The intrusive has sent a multitude of dikes and sills into the associated sediments.

From abstract: The area in the vicinity of the West Fork of the Chulitna River, Alaska, one of those examined in 1931 in connection with the study of mineral resources in districts tributary to the Alaska Railroad, contains numerous prospects but, as yet, no productive mines. Its placer deposits are negligible but some of its lodes may prove valuable for gold and silver and perhaps also for copper and arsenic.

This report provides and in-depth description of the Moose Pass-Hope District in Alaska, including on overview of the general area, physical geology, and economic geology.

From abstract: To help the mining industry of Alaska and to assist in the development of the mineral resources of the Territory have been the prime motives of the Geological Survey's investigations in Alaska during the past 35 years, in which nearly one half of the Territory has been covered by its reconnaissance and exploratory surveys. It was natural, therefore, that the Alaska Railroad, when it undertook intensive consideration of the problem of finding tonnage that would increase its revenues, should look to the Geological Survey to supply technical information as to the known mineral deposits along its route and to indicate what might be done to stimulate a larger production of minerals and induce further mining developments and prospecting that would utilize its service.

From abstract: The gold quartz veins of the Willow Creek district belong to the type of ore deposits that may be expected to continue downward for several thousand feet below the present surface. The veins occur in an essentially homogeneous quartz diorite intrusive mass, batholithic in form ; therefore, the composition of the wall rock plays practically no significant part in the distribution of gold within the veins. The veins were formed partly as fissure fillings and partly by replacement of the wall rock along fractures and of fragments of wall rock caught between the fracture walls. Structurally the deposits are essentially composite lodes, although quartz lenses of considerable size have also been formed.

From abstract: Two deposits of high-grade gypsum are located near tidewater at Iyoukeen Cove, on the northeastern part of Chichagof Island, southeastern Alaska. A group of claims, formerly operated by the Pacific Coast Gypsum Co., was acquired by the Kaiser Gypsum Division of Kaiser Industries, Inc., during World War II. Claims at the other deposit are held by Dave Housel of Juneau and Seattle, Washington, in the name of the Gypsum-Camel group.

From abstract: Gypsum-bearing rocks crop out in Gypsum and Yellow Jacket Gulches, on Sheep Mountain, which is about 90 miles northeast of Anchorage, Alaska. The gypsiferous rock occurs in deposits of irregular shape in the greenstone. Both the gypsiferous rock and the greenstone are hydrothermal alteration products of the volcanic rocks of Jurassic age which comprise the bulk of the mountain. Near-surface samples of the gypsiferous rock contained an average of 25 to 30 percent gypsum ; some contained as much as 50 percent. Quartz, alunite, clay, sericite, and pyrite are contaminating constituents of the ore. Six of the largest and most accessible of the gypsum deposits were mapped and calculations show that three of the deposits contain an aggregate of approximately 311,000 short tons of indicated gypsiferous rock and four of the deposits contain 348,000 short tons of inferred gypsiferous rock.

From introduction: This report describes the destructive effect of permafrost on cultivated fields and delineates the parts of the Fairbanks area which are least suitable for agriculture because of the character of the underlying permafrost. Studies by the author indicate that agriculture will be affected by similar permafrost conditions throughout areas on the north side of the Tanana Valley within 100 miles of Fairbanks.

From abstract: On the west coast of Chichagof Island, southeastern Alaska, are three nickel-copper deposits that consist of norite containing the sulfide minerals pyrrhotite, pentlandite, and chalcopyrite. The deposits are within less than a mile of each other and are, by water, 160 miles southwest of Juneau and 70 miles northwest of Sitka. The norite is part of a stock, about 5 square miles of which is above sea level. Other rocks of the stock are amphibolite, amphibolitic norite, gabbro, diorite, quartz diorite, monzonite, granite, pegmatites, quartz veins, and schist inclusions. The stock is intrusive into a Lower Cretaceous (?) graywacke formation and an Upper Triassic (?) greenstone formation, both of which are now metamorphosed to schist.

Abstract: At Snipe Bay, on the outer coast of Baranof Island, about 46 miles southeast of Sitka in southeastern Alaska, is a nickelcopper deposit that consists of a mass of basic rock intruded into quartzite and quartz schist. Neither the size nor the grade of the deposit is adequately known. Natural exposures and those in a few prospect openings indicate that to an assumed depth of about 130 feet below the lowest point on the outcrop there is a reserve of about 430,000 tons of low-grade nickelbearing material, which, to judge from available assays and from comparison with similar material from other places, probably does not contain more than 0.3 percent each of nickel and copper. The deposit thus appears too small and of too low grade to permit the recovery of the nickel and copper except at a considerable financial loss; but as the location is favorable for largescale, low-cost development, further prospecting may be justified, in the hope that a moderate amount of surface stripping, plus a few diamond-drill holes, might indicate that the deposit is larger, and possibly of higher grade, than it is safe to infer from the available data.

From abstract: The Stampede Creek area lies about 120 miles southwest of Fairbanks, Alaska. It is most readily accessible by air during the summer and by tractor road during the winter. Since 1936 approximately 2,400 tons of shipping-grade antimony ore and concentrates, containing about 1,300 tons of metallic antimony, have been produced at the Stampede mine. The mine was closed down in the spring of 1941, principally because of the high cost of transportation. The area is underlain largely by metamorphosed rocks of the Birch Creek schist. The schist has been warped and crumpled into many broad, open folds which strike northeast and also plunge to the northeast. The Stampede mine is in the schistose quartzite member of the Birch Creek schist.

From abstract: The nickel-copper deposit near the north end of Admiralty Island, about 18 miles in an airline west of Juneau, in southeastern Alaska, consists of a basic sill which averages somewhat more than 100 feet in thickness. The sill, which dips eastward, is intrusive into a thick sequence of phyllite and various types of schist. The rock of the sill consists principally of the silicate minerals labradorite and olivine, but it also contains magnetite and the sulfides pyrrhotite, pentlandite, and chalcopyrite. It assays, on the average, about 0.34 percent nickel and 0.35 copper, which are doubtless mostly in the pentlandite and chalcopyrite respectively but are probably constituents of other minerals also. A significant proportion of nickel and copper is probably contained in the olivine and perhaps in the pyrrhotite.

From abstract: This paper describes the geology of a part of the Alaska Range, extending from the Delta River to the international boundary between Alaska and Canada, and of an additional area that includes part of the Wrangell Mountains and the upper Copper River valley.

From introduction: This paper describes the geology of the Prince William Sound region, a part of south-central Alaska. It deals with the rocks of a section of the Coast Ranges that has been studied by various geologists over a period of many years and still offers basic problems that are unsolved. Prince William Sound is well known for its mining activities, but the intention here is to describe the areal and stratigraphic geology of the district rather than its mineral resources and to present a statement that will serve as a report of progress and a basis for more detailed field work.

From abstract: The Jarvis Creek coal field lies on the north side of the Alaska Range, between latitudes 63 35' and 63*45' N., and longitudes 145*40' and 145*50' W. It is 3 to 6 miles east of the Richardson Highway. The coal field is about 16 square miles in area, the major part of which is a rolling plateau that slopes gently northward and is bounded on the east, south. and west by bluffs facing Jarvis Creek, Ruby Creek, and the Delta River.

From introduction: The Red Bluff Bay area was examined briefly for the Geological Survey by John C. Reed and others in 1939. During the summer of 1941 the writers, with R. E. L. Rutledge, mapped this area on a scale of 1:12,000, and examined the serpentine masses in the interior during the course of reconnaissance trips into the surrounding region.

From introduction: The presentation of a yearly record of the Alaska mineral industry is a continuing service that has been rendered by the Geological Survey from almost the earliest years of extensive mining in Alaska, and the present report, for 1938, is the thirty-fifth of this series. 2 Such a record, especially when supplemented by the statistics for the preceding years, not only affords an authoritative summary of current 'and past conditions but also indicates trends that are of significance in suggesting the lines along which future developments of the industry are likely to proceed. These reports therefore serve miners, prospectors, and businessmen concerned with Alaska affairs as useful historical records, statements of contemporary conditions, and starting points on which some conjectures concerning future operations may be predicated.

This report describes the results of expeditions to map the geologic and topographic features of the Kantishna region of Alaska.

From introduction: This paper describes the geology of a part of the Alaskan Range that lies in the headwater region of the Copper and Tanana Rivers.

From introduction: The present report aims to supply additional information regarding the Tertiary deposits, which are the source of most of the gold placers now being worked in that part of the Eagle-Circle district lying south of the Yukon River. The work was conducted from base camps along the river, but the belt of Tertiary rocks is at places as much as 20 miles from the Yukon, so that it is not easily accessible from the river except in the vicinity of mining camps, where roads or trails have been constructed southward.