Abstract: Structure drilling under Contract No. AT(05-l)-120 was begun May 13, 1951, and was suspended June 30, 1951, at Red Rock, Arizona with the completion of 12 holes and 2,390.5 feet of drilling. No mineralization was disclosed in the widely spaced holes. The structure and rock composition was found favorable for a potential drilling area.

Abstract: Mesas 1 1/2 and II 1/2 were investigated in October 1951, to determine the extent and degree of uranium mineralization in the Salt Wash sandstone. Carnotite-vanoxite-type minerals are sufficiently concentrated to recommend 14,600 feet of drilling.

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.

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draft copy was only recently located and is being published at this time because of the interest in the contained historical content.

Abstract: Ten days were spent during June 1955, examining the sedimentary rocks along the San Juan and Colorado Rivers between Mexican Hat, Utah, and Lee's Ferry, Arizona. The most favorable area for uranium deposits occurs in the Shinarump member of the Chinle formation between Clay Hills Crossing and Spencer Camp along the San Juan River. Mineralization is spotty and deposits are small and almost all below ore-grade. Only one small mine, the Whirlwind, is currently producing ore. Gray-green alteration of the underlying Moenkopi is moderately developed in the vicinity of the Whirlwind mine; elsewhere alteration is weakly developed.

From purpose and scope: This report is designed to summarize the available information on the geology and ore reserves of the uranium deposits. Detailed geological work has been confined largely to those areas which contain the more promising uranium occurrences with at least 80 percent of such work being concentrated in the Sierra Ancha district.

From objectives: In the Salton Sea Quadrangle, reported uranium occurrences were evaluated, and geologic environments thought to be favorable were examined. This report includes the field data collected during that work and a summary of the quadrangle geology and uranium favorability. This is the final report to be prepared on this quadrangle under the NURE program.

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

Supplementary data containing an index map of uranium occurrences in Gila County to accompany a report on U.S. uranium resources in Gila County, Arizona.

Appendices containing data on uranium availability in the Salton Sea Quadrangle in addition to tabulated chemical and water analyses to accompany a report on U.S. uranium resources in California and Arizona.

Report and corollary maps on the Eurida (Toh Atin) District, Carrio Uplift, Arizona.

Discussing an investigation made to search for the evidence of channels for hydrothermal uraniferous solutions in the diatremes of the Hopi Buttes volcanic field.

Discussing an examination made of uranium deposits on the southwest rim of the Lukachukai Mountains, in Northeast Arizona