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Results for “Trace Elements Memorandum”

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At least 91 records · Page 5Linked to original sources
USGS1957

Uraniferous coal and carbonaceous shale in northeast Parana, Brazil

Uraniferous coal has been found in northeast Parana, Brazil, in the Rio Bonito formation of Pennsylvanian age. In the majority of coal samples taken the uranium oxide content ranges from 0.005 to 0.030 percent, but selected screened samples have contained as much as 0.445 percent uranium oxide. The sampled thickness of the coal seam ranges from 17 to 54 centimeters and averages 31 centimeters. Channel samples across the entire thickness of the coal zone were taken in two places. All other samples were taken as grab samples from either mine waste dumps or coal zones that had high radioactivity. Sufficient information is not yet available to justify any detailed considerations of such features as geologic distribution, mode of occurrence, and radioactive equilibrium conditions of the uranium in the coal.

Trace Elements Memorandum↗
USGS1957

Reconnaissance for radioactive materials in the southern part of Brazil

During 1954-1956 a reconnaissance for radioactive minerals was made with carborne, airborne and handborne scintillation equipment in the southern Brazilian states of Rio de Janeiro, Sao Paulo, Parana, Santa Catarina and Rio Grande do Sul. During the traverse covering more than 5,000 kilometers the authors checked the radioactivity of Precambrian igneous and metamorphic rocks, Paleozoic, Mesozoic and Cenozoic sedimentary rocks, and Mesozoic alkalic intrusive and basaltic extrusive rocks. The 22 samples collected contained from 0.003 to 0.029 percent equivalent uranium oxide and from 0.10 to 0.91 percent equivalent thorimn; two samples were taken from radioactive pegmati tes for mineralogic studies. None of the localities is at present a commercial source of uranium or thorium; however, additional work should be done near the alkalic stock at Lages in the State of Santa Catarina and at the Passo das Tropas fossil plant locality near Santa Maria in the state of Rio Grande do Sul. Near Lages highly altered alkalic rock from a dike contained 0.026 percent uranium oxide. At Passo das Tropas highly altered, limonite-impregnated sandstone from the Rio do Rasto group of sedimentary rocks contained 0.029 percent uranium oxide.

Trace Elements Memorandum↗
USGS1958

Reconnaissance for radioactive rocks in the Paulo Afonso Region, Bahia, Brazil

Ground and air traverses were made to the northwest, north and northeast of Paulo Afonso, Bahia, Brazil, covering Precambrian crystalline rocks and sedimentary rocks of the Jatoba series of Jurassic or Cretaceous age. No important radioactivity anomalies were found; samples from the two strongest anomalies had an equivalent uranium-oxide content of 0.002 percent and 0.006 percent.

Trace Elements Memorandum↗
USGS1951

Uranium occurrences on the Blue Jay Claim, White Signal District, Grant County, New Mexico

A discovery of secondary uranium minerals on the Blue Jay claim was reported in 1949 and the occurrence was examined by the authors in March 1950, The Blue Jay claim is about three-fourths of a mile south of White Signal, Grant County, N. Mex. in sees, 23 and 26, T. 20 3., R. 15 W. , New Mexico principal meridian. The Blue Jay claim is underlain by a pre-Cambrian granite mass that was intruded by numerous dikes ranging from rhyolite to basalt in composition. Abnormal radioactivity and secondary uranium minerals occur in altered rocks near oxidized quart z-pyrite veins. Forty-four samples ranged in grade from 0.001 to 0.11 percent uranium. The intermediate and basic rocks seem to have been the more favorable host rocks for the deposition of secondary uranium minerals, possibly because of their higher phosphate content.

New Mexico↗
USGS1951

Apache Trail uranium prospect, White Signal district, Grant County, New Mexico

The Apache Trail uranium prospect in the White Signal district, Grant County. N. Mex., was mapped by the Geological Survey in May 1950. Pre-Cambrian granite is cut by a diabase dike and a parallel quartz-hematite vein, both of which strike easterly and dip 60 to 65 degrees north. Small quantities of copper carbonates and bismuth-gold ore have been mined. The quartz-hematite vein is moderately radioactive and, although no uranium minerals were seen, two samples contained about 0.01 percent uranium. The diabase dike locally contains torbernite. Two samples of diabase contained about 0.04 percent uranium.

New Mexico↗