Abundances of uranium, thorium and potassium from some plutonic rocks in northern Washington
No abstract available.
Geology topics
Publications and source records attributed to C. A. Bush.
No abstract available.
This report contains a tabulation of the basic radioelement and radiogenic heat data obtained during an Australian National University (ANU) - United States Geological Survey (USGS) heat-flow project, directed jointly by J. C. Jaeger (ANU) and J. H. Sass (USGS). Most samples were collected during the periods June through September, 1971 and 1972. The measurements were made subsequently by two of us (C. M. Bunker and C. A. Bush) using the gamma-ray spec trometric techniques described by Bunker and Bush (1966, 1967). Interpreting the spectra for quantitative analyses of the radioelements was accomplished with an iterative leastsquares computer program modified from one by Schonfeld (1966). Uranium content determined by gamma-ray spectrometry is based on a measurement of the daughter products of 226 Ra. Equilibrium in the uranium-decay series was assumed for these analyses . Throughout the report, when U content is stated, radium-equivalent uranium is implied. The coefficient of variation for the accuracy of the radioelement data, when compared to ana lyses by isotope dilution and flame photometry is about 3 percent for radium-equivalent uranium and thorium and about 1 percent for potassium. These percentages are in addition to minimum standard deviations of about 0.05 ppm for U and Th, and about 0.03 percent for K.
Uranium, thorium, and potassium concentrations were measured in 60 samples collected from an exploratory hole drilled in the Belmont stock about 40 miles north-northeast of Tonopah, Nev. The results indicate that, at least within 2,000 feet of the surface, the granitic pluton contains radioelement concentrations similar to those in average granodiorites and that local variations in concentrations may reflect the effects of argillic alteration.
Uranium, thorium, and potassium contents were determined in 94 samples of drill cuttings from a 9,774-foot-deep exploratory hole drilled entirely in crystalline schists of the basement complex of the Yukon-Tanana Upland. The data indicate two distinctively different rock types and reflect differences in the calcite content of the rock. Zones of anomalously high concentrations of the radioelements probably reflect the effects of the emplacement of the nearby Eielson pluton.