From introduction: This report on the geology of the Powder River Basin is one of a series of reports by the Geological Survey on sedimentary basins in the United States.

Introduction: The U.S. Geological Survey is appraising the possibility, however slight, that the ground water beneath the Nevada Test Site, possibly contaminated by nuclear detonations, may carry radioactive fission products to places where they may constitute a public hazard.

From introduction: The general objectives of this Geological Survey were to study the geologic and geophysical studies of the effects of underground nuclear explosions under Rainier Mesa.

From abstract: This report presents details of two test holes which were drilled to determine ground-water conditions in the near vicinity of the nuclear shot point.

Abstract: A suite of 50 rock specimens, collected by the 1947 Washburn Mount McKinley Expedition, was scanned radiometrically. The maximum radioactivity observed in any one of the specimens was about twice background. Radiometric analyses of the most radioactive samples show that a sample of vein quartz coated with manganese oxide contains 0.009 percent equivalent uranium and that the maximum equivalent uranium content of granitic rock types is .004 percent. The radioactivity of the manganese-stained quartz is probably due to traces of uranium in the manganese mineral, whereas that of the granitic rocks is due to radioactive accessory minerals.

Abstract: The scope of the semiquantitative spectrographic method for the analysis of minerals, rocks, and ores previously described as determining 55 elements, has now been increased to 68 elements which can be estimated in one exposure of a l0-mg sample. Fluorine, the 69th element, requires a separate exposure for some materials. The method has been used to complete about 185,000 determinations in the past two years. Listed in this report are 336 chemical check analyses that indicate approximately 8 percent disagreements in the magnitude of one 10 percent bracket. No chemical and spectrographic results differ by a factor of more than 10.

Abstract: For a number of years the Geological Survey has employed core drilling as a means of obtaining samples of underground formations for use in exploring and evaluating mineral deposits. During 1951, however, experiment with less expensive methods showed that, for analytical purposes, wagon-drill cuttings could be used as effectively as cores, provided a practical method were devised for recovering them in suitable form. The recent development of such a method has made it possible, in places where the depth of drilling does not exceed 125 feet, to supplant thousands of feet of core drilling by wagon drilling which is much faster and which can be done at approximately one-third the cost of the former method. This report describes the sampler and discusses performance, maintenance, and operating costs.

Abstract: Several radioactive deposits were found as a result of reconnaissance in the Gold Hill mining area, Boulder County, Colo. The ore deposits of the area have been worked chiefly for gold. All ore shipped has come from fissure veins, most of which are gold telluride veins. There are, however, some important sulfide veins which show a vague zonal distribution of pyritic gold ores and silverlead ores. The results of this reconnaissance suggest a possible relationship of the radioactive deposits to this indistinct sulfide zoning; however, the zoning is so obscure that its practical application to prospecting for uranium is of doubtful value at the present time. Pitchblende, torbernite, metatorbernite, and schroeckingerite have been identified in specimens from the area; however, no uranium minerals have yet been identified from most of the radioactive deposits, and the uraniferous material present is probably in disseminated small particles. Although selected samples from several localities assay 0.10 percent uranium or more, the known deposits are small and probably are not of immediate economic importance

From introduction: A program of uranium investigations and geologic mapping on the Navajo Indian Reservation in Apache and Navajo Counties, northeastern Arizona (fig. 1) was undertaken by the U. S. Geological Survey on behalf of the Atomic Energy Commission during the field seasons of 1951 and 1952. Field work on this program has been completed and preliminary copies of the maps, which cover an area of about 700 square miles, are inclosed as part of this report. The two principal objectives of the program were to establish geologic criteria useful as guides in prospecting for uranium deposits, and to appraise the favorableness of the Shinarump conglomerate and other Triassic rocks for the occurrence of uranium deposits in order to select areas that deserve exploration for concealed deposits.

From abstract: A reconnaissance for sources of radioactive material in North Dakota and eastern Montana was made in 1948. This reconnaissance was followed by a more detailed survey of parts of Golden Valley and Slope counties, southwestern North Dakota, in June 1949. The radioactivity of representative sections of all formations known to be exposed in the area and of three manganiferous spring deposits was determined with portable Geiger-Mueller counters. At 86 localities 82 samples were taken of these formations and also of 10 ground and surface waters.

The following report describes the findings from an investigation of a uranium-bearing strata undertaken in Hickman and adjacent counties in west-central Tennessee during the summer and fall of 1944. The strata contained radioactive elements within the Chattanooga shale and the Maury glauconitic member of the Ridgetop shale.

Report discussing a study of the mineralogy of various Jurassic and Cretaceous claystones and siltstones of Colorado and Utah. The study was aimed at determining which minerals characterize fine sediments which include important uraniferous strata.

A report about developing a rapid spectrographic method for the determining of hafnium and the hafnium-zirconium ratio in the mineral zircon.

Report discussing progress made on geologic studies under the Colorado Plateau Project. The geologic studies that were in progress during the time of this report consist of the following: "(1) General geologic mapping in southwestern Colorado and southeastern Utah. (2) Regional stratigraphic and sedimentary studies in Colorado, New Mexico, Utah, and Arizona. (3) Studies of past and present ground-water conditions in southwestern Colorado and southeastern Utah."

Report summarizing information regarding the mineralogy of uranium ores of the Colorado Plateau. The report includes sections on classification, mineralogy of the primary unoxidized ores, oxidation sequence and mineralogy of vanadiferous uranium ores, mineralogy of oxidized nonvanadiferous uranium ores, relation of oxidation to water saturation of ore, relative stability and size of oxidized deposits, secondary enrichment, and time and depth of oxidation.

Report discussing a machine increases productivity of the fluorimetric method for uranium determination by preparing several phosphor at once.

The following report covers investigation work done on the distribution of thick deposits of salt that had occurred in the Paradox member of the Hermosa formation of Pennsylvanian age in an area nearly 12,000 square miles of southwestern Colorado and southeastern Utah.

Report discussing a series of geological investigations of the Wet Mountains in Custer County, Colorado, including reconnaissance for thorium and detailed topographical mapping of the area. The investigations took place from 1950-1952.

A report about carnotite-bearing sandstone and clay which has been found in the Chadron formation of the White River group of Oligocene age in the southern part of the Slim Buttes area, Harding County, S. Dakota. The mineralized sandstone contains as much as 0.23 percent uranium.

Report describing a wagon drill used for collecting samples of underground rock formations, as well as its performance, maintenance, and operating costs.

Report discussing the uranium-containing radioactive granite of the Miller House-Circle Hot Springs area of east-central Alaska.

Report summarizing the research done by the Geochemistry and Petrology branch of the Trace Elements Section during the period from July 1 - September 30, 1951. Research includes mineralogic and petrologic investigations of radioactive rocks, minerals, and ores, as well as investigations of chemical, spectrographic, and radiometric methods of analysis to be applied to radioactive materials such as uranium, thorium, and their compounds.

The following report studies the occurrence of the vanadium oxide mineral, doloresite, that has been identified in 11 mines on the Colorado Plateau.

Report discussing a study on four beds of uranium-bearing lignite from the Slim Buttes area of Harding County, South Dakota.