Abstract: The uranium deposit at the Silver Cliff mine near Lusk, Wyo., consists primarily of uranophane which occurs as fracture fillings and small replacement pockets in faulted and fractured calcareous sandstone of Cambrian(?) age. The country rock in the vicinity of the mine is schist of pre-Cambrian age intruded by pegmatite dikes and is unconformably overlain by almost horizontal sandstone of Cambrian(?) age. The mine is on the southern end of the Lusk Dome, a local structure probably related to the Hartville uplift. In the immediate vicinity of the mine, the dome is cut by the Silver Cliff fault, a north-trending high-angle reverse fault about 1,200 feet in length with a stratigraphic throw of 70 feet. Uranophane, metatorbernite, pitchblende, calcite, native silver, native copper, chalcocite, azurite, malachite, chrysocolla, and cuprite have been deposited in fractured sandstone. The fault was probably mineralized throughout its length, but because of erosion, the mineralized zone is discontinuous. The principal ore body is about 800 feet long. The width and depth of the mineralized zone are not accurately known but are at least 20 feet and 60 feet respectively. The uranium content of material sampled in the mine ranges from 0.001 to 0.23 percent uranium, …

From abstract: The central part of the Commodore fault system is in the western Kentucky fluorspar district, in Crittenden County, about 6 miles northwest of Marion. It has yielded from 30,000 to 40,000 tons of crude fluorspar and nearly 20,000 tons of zinc ore. Limestones, sandstones, and shales of the Meramec, Chester, and Pottsville groups of Carboniferous age crop out as relatively flat-lying beds, except near faults. The rocks are transected by high-angle normal faults. The main faulted zone is the Commodore fault system, which displaces the beds from 1,500 to 2,000 feet. The principal vein minerals are fluorite, calcite, smithsonite, sphalerite, and galena. Fluorite and smithsonite are the chief ore minerals, occurring as lenses along the faults. The mines have been worked since 1892, but most of the workings are caved or filled with water.

Abstract: The Moore Hill fault system in the central part of the Kentucky-Illinois fluorspar field is about 26 miles long. Fluorspar has been produced from a part nearly 5 miles long, and since mining began in 1899 this system has yielded more than 300,000 tons of fluorspar. Lead and zinc sulfides commonly are found in the ore, but only rarely do they occur in sufficient quantity to be worth recovering. The productive part of the fault system was mapped and the properties and principal mines described. The high-angle normal faults of the system cut limestones, sandstones, and shales of Mississippian age. Stratigraphic displacements range from less than a foot to as much as 550 feet. The fluorspar bodies are sporadically distributed in veins of calcite and fluorite along the faults.

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: 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 Jonesville district is in central Lee County in the extreme southwest corner of Virginia. It includes an area that is 25 miles long from northeast to southwest and averages 6 miles in width. Most of the district lies within a broad lowland named the Powell Valley, but the district includes Wallen Ridge, which bounds Powell Valley on the southeast.