Report providing information from 125 samples of rock studies, analyzed by using a emission-spectographic method. The studies take place in Yellowstone National Park and Steamboat Springs, Nevada.

Abstract: Steamboat Springs is a presently active equivalent of epithermal gold-silver ore-forming systems. Hot-spring sinter deposits contain small amounts of gold, silver, mercury, antimony, and arsenic. Hot-spring activity probably started before extrusion of the basaltic andesite of Steamboat Springs. Old sinter from the Steamboat Springs system occurs in gravels above and below the basaltic andesite. Intense hydrothermal alteration, including almost complete replacement by hydrothermal potassium-feldspar, has affected the basaltic andesite. Three plagioclase separates of differing potassium content from fresh basaltic andesite yielded potassium-argon ages of 2.52 to 2.55 m.y. Basaltic andesite almost completely replaced by potassium-feldspar yielded an age of 1.1 m.y. The source of energy for the thermal convection system is probably a large rhyolitic magma chamber that supplied the pumice and from which the rhyolite domes were emplaced. Sanidine and obsidian from four of the rhyolite domes yielded potassium-argon ages of 1.15 to 1.52 m.y. and obsidian from one of the northeastern domes yielded apparent ages of 2.97 and 3.03 m.y. The data indicate that hydrothermal activity has occurred at Steamboat Springs, possibly intermittently, for more than 2-1/2 m.y. These data agree with other radiogenic age studies indicating 1- and 2-m.y. lifetimes for the hydrothermal systems that generate …

Abstract: Secondary uranium minerals occur along narrow silicified northeast-trending fractures in Tertiary volcanics of rhyolitic composition. Two zones containing uranium minerals are present.

Abstract: The results of both dry and wet attritioning of Temple Mountain ore are presented. In order to obtain effective attritioning on this ore, the amphaltite must be removed before attritioning. With the asphaltite present, dry attritioning causes a build-up of asphaltite on the surface of sand grains, with consequent loss of uranium values. In wet attritioning, the asphaltite is not broken down or attritioned, because of its low specific gravity and resilience.

Report issued by the U.S. Bureau of Mines discussing the mine stations and safety cars used to reach miners in distress. As stated in the report, "the purpose, equipment, personnel, and construction of its safety cars" is presented. This report includes an illustration, and a map.