The following report provides information that follows investigations of radioactivity in certain rocks found in Wyoming and South Dakota during the summer of 1945. Uranium is the principal element in this report with thorium as secondary.

Report discussing an exploratory drilling program in the Charles T. area and vicinity during the period from November 1947 and September 1949. "The purpose of the exploration was to discover new carnotite deposits to support milling operations on the Colorado Plateau, and to appraise the uranium and vanadium resources of the area explored."

Report discussing the geology of the Wood vein and East Calhoun mine areas of Gilpin County, Colorado.

Report summarizing the general geologic relations of some uranium deposits in the San Juan Basin, speculating on the origin and localization of some individual deposits and the entire SanJuan Basin mineral belt, and attempting to appraise the chances for discoveries of additional deposits.

The following report provides findings of trace elements from investigations on Cache and upper Peters Creeks in the Tentana District, Alaska after discovering radioactive minerals within Geological Survey's collection of Alaskan placer deposits. This investigation took place in the summer of 1945.

Report discussing a comparison of three methods of sample splitting for grain counting: the microsplit, the cone splitter, and hand quartering.

Report discussing a study of uraniferous lignite collected from three coal beds from Harding County, South Dakota. The report contains information regarding the location and geologic setting of the coal, the materials studies, coal petrologic studies, and a discussion of results.

A report about spectrographic determination of lead in zircon and in some other minerals has been made by the U. S. Geological Survey to provide data in a study of the age of the rocks that contained these particular minerals. Overall, standard spectrographic procedures were applied, including the split-filter method for calibrating the photographic emulsion.

A report which investigates three different rock samples that have been contaminated through pulverization in heavy machinery.

The following report covers the study of electrical properties of the Morrison formation in the Uravan mineral belt of the Colorado Plateau to determine if there are anomalous variations in these properties in and near zones of uranium-vanadium minerals which might serve as a target for geophysical prospecting.

Report discussing a geological study of the mineralogy of the carnotite ores of the Colorado Plateau. The report reviews the work done during the 1948 field season and proposes work to be done during the 1949 season.

Abstract: "Lead-alpha activity age determinations were made on zircon from seven granitic rocks of central and southeastern Alaska. The results of the age determinations indicate two periods of igneous intrusion, one about 95 million years ago, during the Cretaceous period, and another about 53 million years ago, during the early part of the Tertiary. The individual ages determined on zircon from 2 rocks from southeastern Alaska and 1 from east-central Alaska gave results of 90, 100, and 96 million years; those determined on 4 rocks from central Alaska gave results of 47, 56, 58, and 51 million years."

Report discussing the results of a geological study of the Idaho Springs-Central City area of the Front Range mineral belt. The study was still in progress at the time of publication.

Abstract: An automatic micromuffle for the determination of the ash content of small samples of carbonaceous material is comprised of a furnace of the radiant-heating type with a direct reading pyrometer for temperature control. This furnace can be assembled with a minimum of labor using parts available from scientific laboratory apparatus companies.

Report summarizing findings of investigations for radioactive source materials in Alaska from 1945 through 1954, and assessing possible Uranium sources in the state.

Report discussing studies of millisite and pseudowavellite, which were "locally abundant in the leached zone of the highly phosphatic Bone Valley formation in west-central Florida." Studies include optical determinations and x-ray studies.

Report discussing the descriptive geology of three new formations of metamorphic rocks and details of about 420 pegmatites in the Fourmile area of Custer County, South Dakota.

Abstract: "A rapid-scanning microphotometer is described with which a 10-inch spectrum may be scanned in two minutes. The resulting chart may be 60, 300, or 1,500 cm long (wavelength scale) and 4 cm high (intensity scale). Commercially available components are used."

Abstract: Reconnaissance for uranium in coal and black shale in New Mexico during 1952 was largely an extension of work initiated during the 1951 field season. No uranium deposits of economic interest were found, although minor amounts of uranium were noted at several localities.

Report discussing a study in which ten samples of carnotite and metatyuyamunite ore that contain more than 0.1 percent lead area analyzed for uranium, radium, and lead.

Report discussing uranium deposits and their origins. Sections include information regarding geochemistry of uranium, occurrence of uraniferous deposits, uraniferous igneous rocks, uranium in vein deposits, sandstone-type deposits, uraniferous coal and associated carbonaceous shale, and uraniferous marine sedimentary rocks.

The following report covers potentiometric studies with hydrogen-sensitive and cation-sensitive glass electrodes supplemented by chemical determinations and X-ray diffractions on a hydrogen-montmorillonite. These studies indicate that the clay behaves as a mixture of two acids, resulting from the presence of interlayer and edge exchange sites, both occupied by hydrogen ions.

Report discussing a radiometric examination that took place in 1950 to determine the grade, reserves, and mode of occurrence of uranium and thorium in east-central Idaho and south-western Montana.

Report discussing an investigation of radioactive Chattanooga black shale found in east central Tennessee.