From introduction: The exploration project at Christmas was carried on cooperatively by the Geological Survey and U. S. Bureau of Mines. Mr. 0. M. Bishop, Engineer for the Bureau of Mines, examined the property and in his report of June 6, 1942 recommended that six holes be drilled from the 800 level of the mine. The Bureau of Mines began drilling in September 1942, and the Survey investigations began a month later. Since any ore bodies discovered below the 800 level would be inaccessible until a deeper level could be developed, the Bureau and Survey decided to explore from higher levels where resulting benefits could be more quickly realized. Drilling from the upper levels was begun early in 1943.

Abstract: This report abstracts the published information on geologic occurrence and distribution of perlite in the United States. Perlite is important in the growing light-weight aggregates industry. The geology and petrology of perlite are described and brief mention is made of mining, milling, processing, economic factors, and reserve figures where known. A table of analyses of the rhyolitic, latitic, and dacitic perlite, welded tuff, pitchstone, and obsidian is included mainly to show the water content. The index map shows known deposits and the geology of areas in which possible deposits may be found. The locations of processing plants are indicated to show their economic relationship to the deposits and to markets.

From introduction: The Stanford-Hobson area project was undertaken by the United States Geological Survey, in cooperation with the United States Bureau of Reclamation, as part of a program for the geologic mapping and investigation of mineral resources in the Missouri River basin. The field work that is the basis of the ensuing report consisted of mapping the geology and determining stratigraphic relationships in sufficient detail to evaluate the mineral resources, especially the oil and gas possibilities in the area.

From introduction: This reconnaissance study was undertaken to determine the major geologic features of the western part of Mineral County, Mont., principally in the drainage basin of the St. Regis River.

From abstract: At the request of the Council of the San Carlos Apache Tribe the U. S. Geological Survey entered into a cooperative agreement calling for a brief reconnaissance study to determine, as far as practical, the mineral potential of the San Carlos Indian Reservation. Five months of field work was done during the winter and spring of 1952-53. About 30 percent of the reservation is covered by alluvial deposits of late Tertiary, Pleistocene, and Recent age, and another 60 percent is covered by volcanic rocks of Tertiary and perhaps Pleistocene age. These rocks are younger than the major epochs of metallization in southeastern Arizona. The remainder of the area is underlain by pre-Cambrian and Paleozoic sedimentary rocks, pre-Cambrian granite, and pre-Devonian diabase.

From abstract: Thorium has been found since 1949 in at least 33 deposits in an area 6 miles wide and 20 miles long in the Powderhorn district, Gunnison County, Colo. The district is underlain largely by pre-Jurassic metamorphic and igneous rocks, most of which, if not all, are pre-Cambrian in age. These rocks are overlain by sandstone of the Morrison formation of Jurassic age, and by volcanic rocks of the Alboroto group and the Hinsdale formation of Miocene and of Pliocene(?) age, respectively.

Abstract: The Murray area includes almost the whole drainage basins of Prichard, Eagle, and Beaver Creeks and is underlain by the pre-Cambrian Belt series which is subdivided, from oldest to youngest, as follows: Prichard formation (upper and lower parts), Burke formation, Revett quartzite, St. Regis formation, Wallace formation, and Striped Peak formation. The Belt series in this area is cut by many small monzonite stocks believed to be related to the Cretaceous Idaho batholith. This report describes only the lead-zinc mines. The lead-zinc production around Murray reached its peak in 1911 and 1912 when the Monarch, Edith Murray (Pontiac or Terrible Edith), Bear Top, Paragon, Black Horse, and Silver Strike mines were active. Many of these mines have produced ore intermittently since then, and the Jack Waite mine has been very active since about 1930.