Abstract: Several radioactive deposits were found as a result of reconnaissance in the Gold Hill mining area, Boulder County, Colo. The ore deposits of the area have been worked chiefly for gold. All ore shipped has come from fissure veins, most of which are gold telluride veins. There are, however, some important sulfide veins which show a vague zonal distribution of pyritic gold ores and silverlead ores. The results of this reconnaissance suggest a possible relationship of the radioactive deposits to this indistinct sulfide zoning; however, the zoning is so obscure that its practical application to prospecting for uranium is of doubtful value at the present time. Pitchblende, torbernite, metatorbernite, and schroeckingerite have been identified in specimens from the area; however, no uranium minerals have yet been identified from most of the radioactive deposits, and the uraniferous material present is probably in disseminated small particles. Although selected samples from several localities assay 0.10 percent uranium or more, the known deposits are small and probably are not of immediate economic importance

Report discussing a study of the mineralogy of various Jurassic and Cretaceous claystones and siltstones of Colorado and Utah. The study was aimed at determining which minerals characterize fine sediments which include important uraniferous strata.

Report summarizing information regarding the mineralogy of uranium ores of the Colorado Plateau. The report includes sections on classification, mineralogy of the primary unoxidized ores, oxidation sequence and mineralogy of vanadiferous uranium ores, mineralogy of oxidized nonvanadiferous uranium ores, relation of oxidation to water saturation of ore, relative stability and size of oxidized deposits, secondary enrichment, and time and depth of oxidation.

The following report covers investigation work done on the distribution of thick deposits of salt that had occurred in the Paradox member of the Hermosa formation of Pennsylvanian age in an area nearly 12,000 square miles of southwestern Colorado and southeastern Utah.

Report discussing a series of geological investigations of the Wet Mountains in Custer County, Colorado, including reconnaissance for thorium and detailed topographical mapping of the area. The investigations took place from 1950-1952.

The following report studies the occurrence of the vanadium oxide mineral, doloresite, that has been identified in 11 mines on the Colorado Plateau.

Report discussing a geological examination for radioactive materials in an area of about 5 square miles near Montezuma, Colorado during the fall of 1952.

A report regarding the distribution and thickness of salt in the paradox basin of southeastern colorado and southeastern Utah. This report concerns work done on behalf of the Division of research of the U.S. Atomic Energy Commission.

Report discussing field work done between 1947 and 1951 for a reconnaissance radiometric survey of the Garfield and Taylor Park quadrangles of the Sawatch Range in Chaffee and Gunnison Counties of west-central Colorado.

"This report briefly describes the [Urvanian Mineral Belt] and outlines the geologic evidence supporting its concept. General plans for continuous exploration of this belt, and preliminary prediction of the total amount of carnotite-bearing rocks that might be in one unexplored area, are also presented"

This report describes the distribution of geologic features that may be used as geologic guides to carnotite deposits, sedimentary trends of the ore-bearing sandstone, and regional structures within and adjacent to the Urvan mineral belt in the Urvan and Gateway mining districts, Montrose and Mesa Counties, Colorado.

A report regarding the appraisal of the accuracy of the U.S. Geological Survey of ore reserve estimates for uranium-vanadium deposits on the Colorado Plateau. This report concerns work done on behalf of the Division of Raw Materials of the U.S. Atomic Energy Commission.

"Thorium deposits were discovered in the Powderhorn district in 1949. This district has long been known for its occurrences of alkalic igneous rocks, of which the best known is the Iron Hill complex (Larsen, 1942). Some of these alkalic rocks contain titanium, barium, strontium, rare earths, thorium, and niobium in greater percentages than those of most igneous rocks. A study of the thorium deposits was undertaken to obtain more information on the geologic relation of minor elements, particularly rare earths, and thorium, to alkalic igneous rocks, and to evaluate the economic significance of the Thorium deposits."