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Results for “Trace Elements Memorandum”

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At least 91 records · Page 5Linked to original sources
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↗
USGS1951

Uranium in the Copper King Mine, Black Hawk No. 1 Claim, Larimer County, Colorado

Radioactive rock was discovered on the dump of the Copper King mine, sec. 8, T. 10 N., R. 72 W., Larirrier County, Colo., in the summer of 1949. The mine had been prospected intermittently for copper and zinc since 1,916, but there is no record that ore was produced. The country rock is pre-Cambrian granite containing many schist inclusions and narrow pegmatite dikes. Pitchblende disseminated in chlorite and sulfides was deposited in an obscure vein system during an intermediate stage of mineralization. This stage was preceded by biotitic alteration of amphiboles and sulfide deposition. The latest stage of mineralization is represented-by the limonitic dense quartz vein followed during mining. The uranium-bearing vein is about 2-3 feet wide and the dense quartz vein is less than 6 inches wide. Both veins are bordered by 1-3 feet of biotite- and sulfide-bearing granite and arriphibole schist. The uranium content of 26 samples taken in the mine and on the dump ranges from 0.002 to 1.40 percent. These samples contained as much as 2.97 percent copper and 5.96 percent zinc. The general outlook for further prospecting near the Copper King shaft is not favorable, because much of the 'immediately surrounding area has been thoroughly investigated without finding abnormal radioactivity. The most favorable environment for concentration of uranium minerals appears to have been in or near schist inclusions in granite, and further exploration in nearby prospects may result in the discovery of other uranium-bearing deposits. In the Copper King mine, additional exploration would aid in determining the extent of the uranium-bearing material.

Colorado↗