Introduction: Geologic studies by the U.S. Geological Survey in support of the U.S. Air Force's Project Pluto in Area 401 of the Nevada Test Site were made on behalf of the U.S. Atomic energy Commission.

Abstract: Geophysical logs, a summary of contract costs, detailed descriptions of drilling, casing, cementing, and hydraulic testing operations, X-ray mineralogical analyses, physical property analyses, and a detailed lithologic log are presented in the report.

From abstract: This report is on the geologic studies in the U12e.07 tunnel for the purpose of determining the structural features, lithographic character, chemical composition, and physical properties of the tuff exposed in the tunnel.

From abstract: This report describes the Rainier underground test of September 19, 1957 conducted at the Nevada Test Site with a 1.7 kiloton nuclear device.

From introduction: This report details the seismic measurements by the USGS during the pre-Gnome high-explosives tests near Carlsbad, New Mexico.

From introduction: This report presents the geologic results of an exploration program conducted by the USGS in the Lost Creek area of Wyoming.

From introduction: Salt occurs at depths less than 500 feet in six salt domes in Texas and Louisiana. Underground mining operations are being carried out in each of these domes. The following notes have been prepared in an effort to furnish data regarding chemical composition and structure of the rock salt in the shallow deposits.

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.

From abstract: Radioactive manganese deposits have been found in two swamps and at one locality on the northeast bank of the Rio Itapicuru near Mosquete, municipio of Itapicuru, State of Bahia, Brazil. The occurrences are related to warm springs and consist of surficial manganiferous sinter and of sandstone impregnated with manganese.

From introduction: The Martha E prospect, in Spring Gulch about three and one-half miles southwest of Idaho Springs, Colo. (fig. 1), is on a claim, originally called the Daisy Freese, which was first prospected by the Stanley Mines. The occurrence of radioactive minerals in the adit was called to the attention of the U. S. Geological Survey in 1950 by the owners of the claim. The Survey's Trace Elements Section Washington Laboratory identified metatorbernite, autunite, and sooty pitchblende.

From abstract: The objectives in the investigation of airborne radioactivity surveying during fiscal year 1951 were: 1) Establishment of a routine technique of airborne radioactivity surveying -- completed by incorporating those phases of the aeromagnetic surveying technique that were applicable; 2) Development of automatic correction of the radiation measurement for variation in distance from source -- achieved by using the radar altimeter output to modify the output of the counting-rate meter in accordance with the observed variation of radiation intensity with distance from a source; 3) Development of more efficient radiation detectors -- including large scintillation detectors.

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: The distribution of the known uranium deposits of the Colorado Plateau is being analyzed in order 1) to test for systematic relationships between that pattern and geologic factors, 2) to help guide exploration, and 3) to appraise the potential resources of the region and of each of its component areas.

From abstract: An investigation of the use of geophysical methods in prospecting for carnotite deposits in the Colorado Plateau was made by the Geophysics Branch of the U. S. Geological Survey between April 21 and June 24, 1949. Results of this preliminary work indicated that electrical resistivity methods could be used successfully.

From abstract: A radioactivity survey of the Black Rock district in southern Yavapai County, Ariz, disclosed anomalous radioactivity in several localities, chiefly at the Abe Lincoln mine in sec. 11, T. 8 N., R. 3 W., about 14 road miles northeast of Wickenburg. The Abe Lincoln vein system occupies a fault zone which strikes N. 500 E. and dips from 780 to 870 NW. Moderate radioactivity is present at the Bracken property and at several other localities in the Black Rock district. The writers recommend re-opening the Abe Lincoln mine to permit a more extensive examination of the vein.

From abstract: The Mineral Hill monazite deposits, 3 to 5 miles northeast of the town of Shoup, Lemhi County, Idaho, were investigated by the U. S. Geological Survey in July 1952. The deposits are replacement veins and lenses along shears in a pendant, principally of pre-Cambrian biotite gniess, about 4 to 5 miles in size and enclosed by granite of the Idaho batholith. The veins consist predominantly of calcite, monazite, and allanite, and contain minor quantities of barite, magnetite, rutile, and apatite.

From abstract: Radium-bearing precipitates derived from 'oil-well fluids have been found in more than 60 oil and gas fields in Cowley, Butler, Marion, Sedgwick, and Greenwood Counties of southeastern Kansas. The abnormal radioactivity of these precipitates has been studied through the use of gamma-ray and sample logs; by radiometric, chemical petrographic, and spectrographic analyses of the precipitates and drill samples; and through the use of chemical analyses of brines collected from oil wells in the areas of high radioactivity.

From introduction: The purposes of this paper are to tabulate and discuss the results of a number of complete disequilibrium analyses, to illustrate a proposed classification of disequilibrium patterns, to study these disequilibria as clues to the understanding of the geochemical history of the samples and of the deposits, and to point out some of the difficulties when simply comparing radioactivity and chemical uranium assays for interpreting equilibrium or disequilibrium in samples.

From abstract: The uranium mineral uranocircite, a barium uranyl phosphate, occurs in a sandstone channel in the Chadron formation of Oligocene age in the White River Badlands, Pennington County, S. Dak. A vertical section of the basal 1-foot of the channel contains 0. 25 percent uranium. There are also small amounts of metatyuyamunite (?) in the upper part of a freshwater lime stone bed in the Chadron formation and carnotite in chalcedony veins in the overlying Brule formation, also of Oligocene age.

From abstract: The Rainy Day mine in the Circle Cliffs area, Utah, is developed Dn a long slender pod of uranium ore. Ore is localized in siltstone of the Moenkopi formation of Triassic age, on the south edge of a channel about 3,300 feet wide by 40 feet deep that is filled with sandstone of the Shinarump member of the Chinle formation of Triassic age. Shale of the Chinle rests directly on siltstone of the Moenkopi on either side of the channel.

Abstract: Pitchblende was discovered in July 1951 in the Alma mining district, Park County, Colo0 , by the U0 S. Geological Survey acting on behalf of the U. So Atomic Energy Commission. The pitchblende is associated with Tertiary veins of three different geologic environments: 1) veins in pre-Cambrian rocks, 2) the London vein system the footwall block of the London fault, and 3) veins in a mineralized area east of the Cooper Gulch fault. Pitchblende is probably not associated with silver-lead replacement deposits in dolomite. Secondary uranium minerals, as yet undetermined, are associated with pitchblende on two London vein system mine dumps, and occur in oxidized vein material.Lfrom dumps of mines in the other environments. Although none of the known occurrences are of commercial importance, the Alma district is considered a moderately favorable area in which to prospect for uranium ore, because twenty-four of the forty-three localities examined show anomalous radioactivity; samples from anomalously radioactive localities, which include mine dumps and some underground workings, have uranium contents ranging from 0.001 to l.66 percent.

From introduction: A tectonic map of most of the Cordilleran Foreland (fig. 2) is being compiled as an aid to study the geologic setting of uranium deposits within the region, and to determine what relationships may exist between the distribution of uranium deposits and the regional tectonic pattern (Osterwald, 1955). The map will show the distribution of faults, uranium deposits, areas of volcanic activity, and crestlines and troughs of folds.

From introduction: The compilation of the tectonic map of Wyoming east of the overthrust belt (area 6, fig. 2) was done by the U. S. Geological Survey on behalf of the Division of Raw Materials of the U. S. Atomic Energy Commission. Structures shown on the map have been obtained from published geologic maps and from unpublished data supplied by Government agencies, private companies, and independent geologists. The tectonic map of Wyoming east of the overthrust belt is only a progress report; any suggestions for corrections or additions will be appreciated.

From introduction: The compilation of the tectonic map of northern Colorado and northeastern Utah (area h, fig. 2) was done by the U. S. Geological Survey on behalf of the Division of Raw Materials of the U. S. Atomic Energy Commission. Structures shown on the map have been obtained from published geologic maps, and from unpublished data supplied by government agencies, private companies, and independent geologists. The various structures of the Foreland can be divided into three large classes to show the relation of uranium deposits to the structural pattern.