Report issued by the U.S. Bureau of Mines on the manganese deposits near Granite County, Montana. It reviews the mining history and geology of the Philipsburg district. The report includes maps and tables.

Report issued by the U.S. Bureau of Mines on the characteristics of oil obtained from the Tensleep Sandstone Reservoir. The samples collected are analyzed for physical characteristics and presented in tables and graphs. The report also includes a map.

A report about phosphates found in the Permian Phosphoria formation of the Rocky Mountains. This area constitutes one of the worlds largest reserves of phosphate.

From introduction: This report describes the program of research on mineralogy and petrography of certain uraniferous vein deposits in the Boulder batholith of western Montana.

From abstract: Uranium minerals and radioactivity anomalies occur in many silver lead veins and chalcedony veins and vein zones in the Boulder batholith of southwestern Montana.

From introduction: A tectonic map for the northern part of the Cordilleran Foreland was compiled to aid in establishing the geologic setting of uranium deposits within the region, and to determine what relationships, if any, exist between the distribution of uranium deposits and localities, and the regional tectonic pattern (Osterwald, 1955). The relationships might suggest new areas favorable for the discovery of uranium deposits in the Cordilleran Foreland as well as in other areas with similar tectonic history. The map will show the distribution of crest lines and troughs of folds, faults, uranium deposits and localities, and areas of volcanic activity. Outcrop areas of Precambrian and post-Eocene rocks are shown to designate the relative age of structures. Where possible the Precambrian rocks are subdivided into structural types, so that their influence on younger deformations may be inferred. The map of eastern Montana is one of a series being prepared before the final map is assembled (fig. 1.).

From abstract: Geologic settings are recognized in central and eastern Montana and in a few places in southwestern Montana that elsewhere are similar to the settings for the occurrence of uranium deposits. Several specific areas in Montana seem favorable for the occurrence of uranium.

Abstract: Anomalous radioactivity and uranium minerals have been found on the dumps of the Comet, Gray Eagle, and Silver Hill mines situated along the Comet-Gray Eagle shear zone. The shear zone is from 50 to 200 feet in width and has been traced 5 1/2 miles. The Gray Eagle mine is currently being reopened but no underground work, with the exception of a few shallow shafts and adits, has been done between the Gray Eagle and Comet mines. Because of the high U3 08 content of the samples from the Comet and Gray Eagle dumps, it is recommended that a minimum of four diamond drill holes totaling 3, 000 feet be drilled by AEC between the two mines to intersect the shear zone 300 to 500 feet below the surface. This drilling should be made contingent upon the results of the Gray Eagle exploration.

From abstract: A reconnaissance to determine the uranium content of granitic rocks in the western states was made during parts of October and November 1951. The paucity of our knowledge of the granitic rocks that are most likely to contain significant quantities of uranium has prevented all but a very general isolation of areas or types of granitic rocks for reconnaissance examination.

From abstract: Nine uranium deposits occur in a small area west of Clancey, Jefferson County, Mont. These deposits are all in or near silicified fracture zones in quartz monzonite and related rocks of the Boulder batholith. The deposits contain pockets of uranium minerals in cavities in brecciated well-silicified rock. The primary uranium mineral pitchblende has been found in one pod. Secondary uranium minerals occur as fracture linings and in pore spaces in and adjacent to the silicified zones.

Abstract: A low-level airborne radioactivity survey of parts of Beaverhead and Madison Counties in southwestern Montana was undertaken from June 6 to October 14, 1955. Flying centered around the Ruby Range-Sweetwater Basin area and concentrated on the Precambrian metamorphic complex and Tertiary lake-bed sediments. No commercial uranium deposits were discovered, and no extensions were found of the few known small occurrences. Five areas of high background detected through the survey were investigated on the ground.

Abstract: An airborne radiometric survey of parts of the east flank of the Big Horn Mountains was begun on June 23, and completed on August 27, 1952. An area of approximately 250 square miles was covered, and only two anomalies were found in the entire area. Flight lines were arranged in accordance with the geology of the area, particular attention being given to formations the stratigraphic equivalents of which are known to be uranium bearing in other areas. Two additional zones of radioactivity were found by ground investigation, but assays from both the ground and the airborne discoveries showed no economic uranium deposits.

Introduction: During the year 1952-1953, research on the Boulder batholith program was largely devoted to basic mineralogy studies of the "siliceous reef" and, to the extent possible at that time, the "base metal" deposits.

From introduction: The present paper is concerned with fisherman-expenditures, fisherman-use, and yield of the fisheries involved, although some data on other aspects of the fishery were obtained.

Report issued by the Bureau of Mines over studies conducted on low-temperature carbonization of coal. Methods and results of the studies are presented and discussed. This report includes tables, illustrations, and photographs.

Report issued by the Bureau of Mines over studies conducted on lead-zinc deposits of Montana. The results of the studies are presented. This report includes tables, maps, and illustrations.

From introduction: This report details the reconnaissance for uraniferous lignites in North Dakota, South Dakota, Montana, and Wyoming during 1948 and 1949.

From transmittal letter: This report contains the results of radiometric examinations of 39 mines and prospects, and a detailed description of the properties examined.

From introduction: This preliminary report details the geology and mineral deposits of the northern Elkhorn Mountains, Montana.

From abstract: Approximately fifty radioactive deposits and nearly fifty properties not abnormally radioactive were examined during a geologic reconnaissance for radioactive minerals in Idaho, Washington, and western Montana during the period July 1952 -- June 1955. The most important uranium deposits are in or near granitic to quartz monzonitic intrusions of probable Cretaceous age in central and northern Idaho, westernmost Montana, and northeastern Washington.

From abstract: The chromite deposits of the central part of the Stillwater complex lie in a belt 9 miles long between the valleys of Boulder River and the West Fork of the Stillwater River in Sweet Grass County, Mont. The chromite occurs as layers near the middle part of the ultramafic zone in the lower part of the complex. The layers, originally horizontal, have been tilted so that they dip northeastwards at angles ranging from nearly horizontal to nearly vertical, and are cut by many cross faults, the largest with a horizontal offset of 3,000 feet. Investigations by the United States Geological Survey and the United States Bureau of Mines have shown that in this belt there are 5 sections ranging in length from 850 to 3,800 feet along the strike where the continuity and grade of the chromite can be reasonably inferred.

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: The origin of the gneissic rocks on the eastern border of the Idaho batholith in the Bitterroot Range, near Hamilton, Mont., has long been in dispute. Lindgren regarded these rocks as the product of stresses related to a normal fault along the front of the range with an eastward dip of about 150. He thought both the hanging wall and the footwall had moved, with a total displacement along the fault plane of at least 20,000 feet. The faulting was believed to have been so recent as to be a major factor in the present topography. Langton appears to accept the concept of faulting but to regard the gneissic rocks as formed much earlier from a granitic rock that was more silicic and older than the Idaho batholith.