Color copies of photomicrograph figures that accompany a report studying uranium in granites in the southwestern United States.

From introduction: The study is essentially an economic evaluation of the construction and operation of nuclear power plants at several designated military installations where increased power generating capabilities of 5 to 40 mwe may be required by the Government during the period 1963 through 1970.

This report is an issue of the original draft copy of the "Interim Staff Report on Uranium Exploration on the Colorado Plateau", dated June 1951. The original draft copy was only recently located and is being published at this time because of the interest in the contained historical content.

The tabulations on these pages include all of the known areas in Colorado, Utah, New Mexico, and Arizona having economically important uranium-vanadium deposits of the type which are generally referred to by the terms roscoe-lite and/or carnotite. Though similar deposits are known to exist in other areas they are to be viewed as being little more than mineralogical curiosities.

Introduction: Vanadium ore is being mined at many places in western Colorado, southeastern Utah, northeastern Arizona, and northwestern New Mexico (fig. 1). Eight mills in this region produced about 4,300,000 pounds of V2 05 in 1942, representing about 90 percent of the vanadium obtained from domestic sources. Although ore production has mostly exceeded mill capacity since 1937, production during the last half of 1942 averaged only about 19,000 tons or ore a month, whereas the capacity of these mills total about 22,000 tons a month. At the expected rate of ore production, ore stockpiles will be exhausted sometime in 1944, and these mills will then have excess capacity. With more intensive prospecting than now practiced, however, it is believed that sufficient reserves can be indicated to sustain capacity operation of these mills for several years. This memorandum is prepared to specify those areas that are considered most favorable from a geologic standpoint for developing large reserves of vanadium ore by prospecting. It is based on intensive studies by the Geological Survey since 1939 in most of the areas that produce vanadium ore.

From introduction: The general distribution of known deposits of vanadium-bearing sandstone, which also contain some uranium and radium, is shown in figure 1 1/ and Exhibit A, plate 53. 2/ During 1939-41 the Geological Survey made detailed geological studies of these deposits in the Uravan district, Montrose County, Colorado, as well as preliminary examinations in other parts of the Colorado Plateau vanadium region. In 1942 detailed geological studies were made o the deposits in the Egnar-Slick Rock district, San Miguel Co., Colo.; 3/ the Carrizo Moungains district, Navajo Indian Reservation, Arizona and New Mexico; 4/ the Placerville district, San Miguel County, Colo. 5/ and the Monticello district, San Juan Co., Utah. 6/ Since May 3, 1943, the Gelogical Survey has guided the Bureau of Mines program of prospecting these deposits in parts of Colorado and Utah.

From introduction and acknowledgements: This report is written to supplement and complete the record contained in some fifty district and special reports already submitted, and duplication of material in district reports has been studiously avoided. The data herein contained are largely of a regional type, inclusion of which was not wholly appropriate to the district reports.

From 1995 sites in the San Juan Mountains area, 1706 water and 1982 sediment samples were collected during June-July 1976 and analyzed for uranium. The area includes the southern third of the Colorado mineral belt which has yielded rich ores of gold, silver, copper, lead, zinc, and molybdenum. The broadly domed mountains are capped by 2500 m of Tertiary volcanics, deeply eroded to expose a Precambrian crystalline core. Adjacent plateaus underlain by Mesozoic sedimentary rocks were included in the reconnaissance. Average value of uranium in water samples from mountains was less than 0.5 parts per billion, from plateaus was 1-2 parts per billion, from Mancos shale areas exceeded 2 parts per billion. Anomalous sediment samples, 40 ppm uranium, came from near Storm King Mountain and upper Vallecito Creek. Other anomalous areas, including the Lake City mining district, were well defined by 4-30 parts per million uranium in sediment and 3-30 parts per billion uranium in water. Anomalous areas not previously reported indicate favorable areas for future exploration.

Abstract: This report consists of four parts, the first three being descriptions of investigations compiled in the period October 1st, 1953 to April 1st, 1954; the fourth part is a summary of progress of the research based on our entire investigations completed prior to April 1st, 1954. The first part comprises a set of preliminary experiments investigating the mineral composition of the sandstones in thin sections, in an attempt to differentiate barren from ore-bearing sandstones. It appears that there are more rock-fragments and particularly more volcanic rock fragments in the ore zone (zone 4, Well C, Bull Canyon). In addition, silica cement appears to be associated with ore and carbonate cement with barren sediments. The second part details the investigation of the mudstones of the Bull Canyon Wells . A mixed layer lattice "illite" and a kaolin mineral are the most prominent in "normal" mudstones. Dye tests suggest there are differences between the clay minerals in the sandstone matrix of the ore zone and barren zone. In addition, the mudstone zones appear to differ in the response to the dye tests. The third part of the report details the bulk density determinations for cores from well B. The results confirm …

Introduction: Studies of uranium-vanadium occurrences in the Four Corners region show that, with the exception of the Lukachuai area, all of the major deposits in the Morrison formation are grouped around the various igneous masses which are scattered irregularly throughout the Colorado Plateau. The pattern of deposition varies from mountain group to mountain group and each will be described separately. Maps accompany this report to supplement the descriptions of ore occurrences in the vicinity of the La Sal, Abajo, Carrizo, and Henry mountains. Elsewhere, it is believed that a written description will suffice.

From abstract: This two-part report provides an essentially complete listing of radioactive occurrences in Colorado, with a comprehensive bibliography and bibliographic cross-indexes.

Rock and stream-sediment samples were collected to define areas favorable for uranium deposits northeast of Gunnison, Colorado. Areas considered most favorable for further exploration are: (1) the Bronco Mountain area, approximately 10 mi south of Taylor Park Reservoir, (2) the area near the Big Red mine, and (3) the area 5 mi north-northeast of Taylor Park Reservoir. On the basis of known deposits in the Marshall Pass and Cochetopa districts, fault contacts between Precambrian granites and Paleozoic or Mesozoic sedimentary rocks are favorable structural sites.

This report is a preliminary evaluation of the uranium resources of the Brushy Basin Member of the Morrison Formation of Late Jurassic age in southwestern Colorado and southeastern Utah. The project, which began July 1, 1976, and was completed October 1, 1976, was carried out by the Bendix Field Engineering Corporation (BFEC) for the Grand Junction Office of the U.S. Energy Research and Development Administration (ERDA).

From purpose of study: The Vallecito Conglomerate of the Needle Mountains area in southwestern Colorado was studied to evaluate the uranium potential of the unit and to test the applicability of the uraniferous Precambrian pebble-conglomerate exploration model in this area. The main thrust of this project is the Vallecito Conglomerate, but the Uncompahgre Formation, which is also in the Needle Mountains area has basal conglomerate that was investigated in a reconnaissance mode. Five specific objectives have been formulated to meet the overall purpose of this project, and these include: a) Determine the uranium distribution in the Vallecito Conglomerate and the basal conglomerate of the Uncompahgre Formation. b) Evaluate the uranium resources of the area to the degree possible utilizing available information and personal field investigations. c) Test the validity of application of the Precambrian quartz-pebble conglomerate model to this area. d) Recommend detailed studies and delineate drilling sites in the area to further evaluate the uranium resources if warranted. e) Recommend additional geologic, geophysical and geochemical studies which would bear directly on evaluation of uranium resources of the Precambrian pebble conglomerates in the Needle Mountains area.

From introduction: This study is part of the United States Department of Energy's National Uranium Resource Evaluation Program to understand the geologic setting, amount, and availability of uranium resources within the boundaries of the United States.

This report provides uranium and other elemental data resulting from the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Cortez quadrangle, Colorado/Utah.

Supplementary data containing locations of uranium deposits in the Brushy Basin project area, Utah and Colorado.

Abstract: The southwestern part of the Colorado Plateau province was studied to test results from experimental simulation of Colorado Plateau type uranium deposits and to search out additional agents influencing uranium precipitation which might be investigated experimentally.

Abstract: Weak uranium mineralization is widespread throughout the Uinta Basin of northeastern Utah and northwestern Colorado, in rocks ranging in age from Permian to Eocene. No commercial ore bodies are known, although formations there have characteristics elsewhere considered favorable for ore deposition.

Abstract: An airborne radiometric survey of the Dakota sandstone and Morrison formation in the Canon City embayment was conducted by the Atomic Energy Commission from November 1, 1953 to December 5, 1953.

From introduction: This is one of a series of three reports on airborne radioactivity surveys in the United States. The reports contain the 185 airborne anomaly maps issued by the U. S. Atomic Energy Commission as a result of the AEC's aerial surveying program conducted from March 1952 to June 1956; two ground reconnaissance maps of Utah also are included. Most of the reconnaissance was done in the western United States.

From abstract: Experimental simulation of Colorado Plateau type uranium deposits is divided into seven parts. The first three summarize the essential features of geological occurrence for the ores. The last four parts outline the results of experimental investigation arranged according to each geological group of features influencing mode of occurrence.

Several relatively small copper-uranium deposits have been found in southwestern Utah along the contact of the Shinarump and Moenkopi formations of Triassic age, at least from the San Rafael Swell area of Emery County, southward through central and eastern Garfield County, southwestward into western Kane County, and westward into the southern part of Washington County.

From summary: This report describes work done in the Pueblo National Topographic Map Series (NTMS) quadrangle, Colorado, by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).