From abstract: The Sumdum copper-zinc prospect is in an alpine region on the mainland of southeastern Alaska, about 50 miles southeast of Juneau and about 25 miles west of the Canadian boundary. The ore-bearing outcrops at the prospect were discovered by the Alaska Helicopter Syndicate during the summer of 1958. The prospect is within a few thousand feet of the western margin of the . Coast Range batholith in regionally metamorphosed rocks that locally -have -been contact: metamorphosed. Most of the known ore deposits are -in the intermediate unit of three metamorphic-rock units that were mapped.

From abstract: The North Bradfield River iron prospect is in southeastern Alaska in rugged terrain about 8 miles southwest of the Canadian boundary and about 15 miles northeast of the head of Bradfield Canal. The prospect includes several magnetite-rich ore bodies of pyrometasomatic origin that are localized in skarn. The skarn forms a small part of a northwestward-trending roof pendant that is enclosed in the composite Coast Range batholith. The dominant rocks of the roof pendant are gneiss, granulite, schist, and marble. The ore, which consists almost entirely of magnetite, contains subordinate amounts of hematite, hydrous iron sesquioxides, pyrrhotite, chalcopyrite, and malachite. The ore bodies are crudely stratiform and apparently discontinuous. The largest ore body exposed is traceable for about 350 feet along its strike and averages about 25 feet in thickness. An accurate appraisal of the economic potential of the prospect was precluded by poor outcrops, local snow cover, and inadequate subsurface data.

From abstract: The area mapped is on the east coast of Prince of Wales Island, southeastern Alaska, about 35 miles northwest of the town of Ketchikan. Deposits of magnetite and copper in the mapped area and on Kasaan Peninsula, which adjoins it on the southeast, have been mined for copper and have produced more than 600,000 tons of ore valued at more than $6 million.

From abstract: The Craig quadrangle, in southeastern Alaska, lies entirely within the Tongass National Forest and includes a large part of Prince of Wales Island, the largest island of the Alexander Archipelago. Sedimentary, volcanic, and metamorphic rocks of Paleozoic and Mesozoic age are exposed as complexly folded and faulted sequences. Paleozoic rocks occupy a broad geanticlinal area comprising Prince of Wales Island and the islands to the west. Metamorphosed Mesozoic rocks form a geosynclinal area along and east of Clarence Strait. Granitic and dioritic stocks and masses, mainly of Mesozoic age, intrude the Paleozoic and Mesozoic rocks. Remnants of volcanic rocks of Tertiary age exist on Suemez Island, and scattered areas of Tertiary clastic rocks and volcanic rocks are exposed near Clarence Strait. Deposits of Quaternary age are mainly thin glacial deposits and narrow bands of stream alluvium.

From abstract: The Mount McKinley quadrangle, in south-central Alaska, includes parts of the Alaska Range, the Tanana and Kuskokwim lowlands, and the Kuskokwim Mountains. Schists of Precambrian age crop out in the northern foothills of the Alaska Range. Sedimentary and volcanic rocks of Paleozoic and Mesozoic age are exposed in the Kuskokwim Mountains, where little is known of their distribution and character, and in the Alaska Range, where they occupy the axial part and northern limb of a great synclinorium. Granitic batholiths, largely of Mesozoic age, intrude the Paleozoic and Mesozoic rocks in the Alaska Range.

From abstract: Buried placer deposits in a belt about 8 miles long by 1 mile wide at Tofty, near Manley Hot Springs, Alaska, have yielded a few hundred tons of cassiterite as a byproduct to the recovery of several million dollars in placer gold.

From abstract: The Homer district of the Kenai coal field is about 100 miles southwest of Anchorage, in south-central Alaska. It covers an area of about 1,100 square miles on the west side of the Kenai Peninsula, between Tustumena Lake and Kachemak Bay. The principal settlement is Homer, at the southern end of the district, which is connected by the gravel-surfaced Sterling Highway with the Alaska highway system and The Alaska Railroad, and is also served by ocean transportation and one airline.

From introduction: This report is based on preliminary surface mapping in the summer of 1952 and on subsurface exploration with a bulldozer powerauger unit in the summers of 1953 and 1954. In 1952 F. F. Barnes was assisted by Alfred Oestreich, geologist, and Lewis Ladwig and Richard Pack, field assistants. From July 2 to August 31, 1953, F. F. Barnes and Daniel Sokol were assisted by W.T. Ashlock and R. E. Rowland, field assistants, and by a bulldozer operator-mechanic. From June 23 to July 27, 1954, Barnes and Sokol were assisted by A. E. Burford and W. S. Hopkins, geologists, and an operator-mechanic.

From abstract: A gold-bearing area of about 7% square miles near the head of Glacier Bay between Reid and Lamplugh Glaciers was first discovered by Mr. Joseph Ibach in 1924. The dominant rock type in the area is granodiorite, which is intruded into bedded rocks that may be of Paleozoic age. The bedded rocks consist of conglomerate, limestone, and black graphitic schist. A light-colored quartz diorite younger than the granodiorite crops out south of the mapped area.

From introduction: The area of this report is in the northern part of southeastern Alaska (fig. 39). It includes about 400 square miles on northwestern Chichagof Island, latitude 5747' to 58*15' N. and longitude 135 57' to 136 35' W. It is covered by U. S. Geological Survey Mount Fairweather A-1, A-2, and Sitka D--7 and D-8 topographic quadrangle maps. The writer's geologic investigation was started in 1946 as a continuation of earlier work on the west coast of Chichagof Island by J. C. Reed and R. R. Coats (1941) of the U. S. Geological Survey.

From abstract: The Geikie Inlet area is in the Glacier Bay region of southeastern Alaska, about 100 miles northwest of the city of Juneau. The area is mountainous with relief of slightly more than 5,000 feet, and the coastline is deeply indented by fiords and inlets. Most of the western half of the area is covered by glaciers.

From abstract: The Mount Katmai area is on the Alaska Peninsula and comprises the Mount Katmai quadrangle, the Cape Douglas area of the adjoining Afognak quadrangle, and parts of the Karluk and Naknek quadrangles. The area, which includes nearly all the Katmai National Monument, is one of high relief and is drained by streams of preglacial origin. At least two ice advances are indicated by the moraine configuration. Present-day glaciation is restricted to numerous alpine glaciers in the mountain areas. Fifteen recently active volcanoes roughly form a line from Mount Douglas to Martin Mountain.

From abstract: Reconnaissance for radioactive deposits in southeastern Alaska in 1952 was centered in three localities: the northern part of Prince of Wales Island and parts of adjacent islands, the Taku Harbor-Point Astley district, and the Hyder area. Significant concentrations of radioactive minerals were found only in the vicinity of Salmon Bay on the northeastern shore of Prince of Wales Island. In this area radioactive carbonate-hematite veins occur along the coast for about 8 miles. The veins are generally short, irregular, and lenticular, but a few can be traced for more than 300 feet between the low-tide line and the forest cover. The width of the veins normally ranges from less than 1 inch to 2.5 feet; several, however, are 5 to 10 feet wide.

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 abstract: Radioactive material in apparently significant amounts was recognized in heavy-mineral concentrates from the gravels of four streams that head in Ear Mountain, Alaska, when collections of the United States Geological Survey were examined for radioactivity in the winter of 1944-45. This area, on the north side of the Seward Peninsula, attracted attention in 1901-02 when cassiterite was discovered in the streams. Subsequent attempts were made to develop copper- and tin-bearing lode deposits.

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: 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.

Abstract: The Portage Pass area is in south-central Alaska, and includes part of the narrow neck of land that joins the Kenai Peninsula with the mainland to the north. This region is in general mountainous, elevations ranging from sea level to more than 4,000 feet on the peaks bordering the area. Several glaciers, all of which are apparently receding, extend into the area. Vegetation, chiefly alder and cottonwood on the valley lowlands and some spruce and hemlock on the lower slopes, extends to an elevation of about 1,000 feet, above which the slopes are bare except for occasional clumps of brush. The bedrock of the entire area is slate, argillite, and graywacke, apparently part of the same great series that extends from the Kenai Peninsula into the Prince William Sound region and is at least in part of Cretaceous age. The only igneous rocks recognized in the area are a few acidic dikes and a small diabase dike. Small, irregular quartz veinlets are widespread. The structure is not only complex but, owing to extensive metamorphism, is in many places obscure. A general northeast strike and steep to vertical dips of both bedding and cleavage planes are the rule, but there …

From abstract: The area here described includes most of the north side of the Alaska Range between the Delta and Johnson Rivers, in one direction, and the axis of the Alaska Range and the Tanana River in the other. Besides the Delta River, its principal streams are Jarvis Creek, the Gerstle and Little Gerstle Rivers, and, at the extreme east, the Johnson River, all of which have glacial sources.

Abstract: In the accompanying report reference is made to all of the deposits in Alaska in which molybdenum minerals have been definitely recognized and reported. None of the deposits have been mined commercially, and none of them have been prospected thoroughly enough to afford quantitative estimates as to their tenor and potential reserves ; in fact, at only a few of the localities has there been more than surficial testing. Forty-one separate and distinct localities where molybdenum minerals occur are listed, and the available information on factors of geologic significance regarding each occurrence is given. A small-scale map of Alaska on which the various localities are indicated forms part of the bulletin, and in the text are extensive references to the various published reports and records of the Survey upon which the statements are based. In spite of the widespread distribution of molybdenum mineralization in Alaska, the remoteness of many of the localities, their handicap through dearth of transportation facilities and labor supplies, and the already wellsupplied condition of the American market for molybdenum ores discourage the early development of any of the known deposits or search for them in unsurveyed areas. These draw-backs will doubtless become -less important factors …

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.

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 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 1939, is the thirty-sixth of this series.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."