Preliminary results of radiometric reconnaissance of parts of the northwestern San Juan Mountains, Colorado

Abstract

Plate 1. Generalized geologic map showing principal structural areas in the San Juan region, Colorado. .In pocket 2. Geologic map showing structure of the Silverton volcanic center and areas nearby,

Preliminary study of radioactive limonite in Colorado, Utah, and Wyoming

“…The Ouray hot springs are in the area described in Burbank's report (Burbank, 1940), and their location is shown on his map. These deposits are briefly described in a later report by Burbank and Pierson (1953).…”

Uranium in the metal-mining districts of Colorado

“…1) have been considered to be potentially the most important uraniferous areas. Discoveries of radioactive deposits in 1951 by the Geological Survey in the Alma, Leadville, and St. Kevin districts (Pierson and others, 1952), and in the upper and lower Uncompahgre and Red Mountain districts in the San Juan Mountains (Burbank and Pierson, 1953), lend some support to this view. However, recent discoveries of pitchblende outside the central mineral belt suggest that uranium is not confined to those districts from which metal production was high.…”

Reconnaissance for radioactivity in the metal-mining districts of the San Juan Mountains, Colorado

“…Survey Circ. 236 (Burbank and Pierson, 1953). y Disequilibrium caused by excess daughter products of uranium} no Th detected.…”

“…The thorium-bearing quartz-carbonafce-pyrite-sphalerite-galena veins in the Precarabrian rocks of the Cebolia district (fig* 2, area 2) were studied briefly in 1951 by Burbank (Burbank and Pierson, 1953). Although local samples containing as much as 0.28 percent thorium were obtained, none of the veins studied seemed to be of economic value, Olson and Wallace (1954) later made a detailed study of the thorium and rare-earth minerals in the Powderhorn district south of the Cebolla district.…”

“…The radioactivity in calcareous tufa the Ouray hot spring (Burbank and Pierson, 1953)> which has been mined for manganese and tungsten, is caused mainly by radium and other daughter 2/ All readings made on samples of hand-specimen size.…”