The carnotite prospects of the Craven Canyon area, Fall River County, South Dakota

Abstract

Carnotite was discovered in June 1~51 in the Crav.en Canyon area, sees. 24 and 25, T. 7 S~~B. 2 E. and what wouid be sees. 19 and 30 of unsectioned T. 7 S.~ R. 3 E. 9 Fall River County 9 S.--Dak. Although little prospecting had been carried out before November 18~ 1951, more than 28 claims had been staked by that date.The known carnotite occurrences are restricted to the b~sal 100 to 150 feet of the Lower Cretaceous Lakota sandstone; most are within 50 feet of a distinctive, paper-weathering, nonradioactive~ carbonaceous, 1-to 3-foot black shale that is 100 to 125 feet above the top.of the underlying Morrison formation. Three favorable zones have been recog- nized~(1) a zone 20 to 30 feet above the carbonaceous shale horizon, (2) a zone 20 to 30 feet below the carbonaceous shale horizon~ and (3) a zone about 25 feet below (2). Possibly a fourth zone may occur 20 feet below (3).The deposits generally ar~ parallel to bedding 9 but in detail are cross-cutting. Widespread carnotite stains.coat fractures in and adjacent to the deposits. These stains are commonly' associated with an un= identified, green mineral stain that contains uranium and vanadium.The only exploitable ore bodies discovered by November 1951 are of small size, but the presence of many widespread and lo~grade deposits suggests that additional commercial deposits may be found by further prospecting.

Stratigraphy of the Inyan Kara group and localization of uranium deposits, southern Black Hills, South Dakota and Wyoming

“…In 1951 uranium was discovered in the southern Black Hills by Jerry G. Brennan of Rapid City, S. Dak. (Page and Redden, 1952). This discovery caused an influx of prospectors and mining companies into the area, resulting in the rapid discovery of many small carnotite-type uranium deposits.…”

Geology of the Edgemont NE quadrangle, Fall River and Custer Counties, South Dakota

“…The first discovery of a commercial uranium deposit in the southern Black Hills was in 1951 in Craven Canyon (NW*4 sec. 30, T. 7 S., R. 3 E.) (Page and Redden, 1952). Since 1951 many deposits ranging from a few tons to more than 50 thousand tons have been discovered within an area of about 50 square miles (pi.…”

Uranium deposits in Fall River County, South Dakota

“…(fig. 32), in June 1951 (Page and Redden, 1952). Additional discoveries have since extended the area of known occurrences.…”

“…1925 (Darton, 1904(Darton, , 1902Darton and Smith, 1904;Darton and Paige, 1925), and subsequently many other geologic studies have been made for special purposes. In 1951 the U. S. Geological Survey (Page and Redden, 1952) and the Atomic Energy Commission described * the first uranium deposits discovered. Later these agencies contributed to the knowledge of the district through geologic mapping, core drilling, and radioactivity reconnaissance using airborne equipment and equipment mounted on automobiles.…”