Geologic Evaluation of Uranium in Plutonic Rocks, Northwestern Arizona

From the introduction, "During the project, 67 plutons were identified and 64 were sampled. The 3 not sampled are large, complex Precambrian batholiths not designated for samp­ling in the contract and their examination would be far beyond the scope of this project. We feel that the Music Mountain - Garnet Mountain and the Cottonwood Cliffs plutons are more likely to contain uranium anomalies than the Cerbat granite. This is based on the known air radiation anomalies and our limited ex­amination of the Cerbat granite. Four plutons known to be Laramide, ranging in age from about 65 through 72 m.y. were sampled: Ithaca Peak, Diamond Joe, Wheeler Wash and Devils Canyon. The Mcconnico diorite (Site 108) could be Laramide. None of the Laramide plutons are radiometrically anomalous. However, Site No. 43, a small quartz-pyrite­chalcopyrite-molbdenite pod in a vein wholly within the Laramide Diamond Joe stock is anomalous, with 159.4 ppm U-NT, indicating that Laramide stocks can gen­erate their own uranium. At the Wheeler Wash copper-molybdenum and uranium pros­pect, uranium seems to occur in the vein-fault contacts of the otherwise "dead" pluton (Site No. 489) and Laramide limonite-sulfide veinlets in the Democrat granite near the \-/heeler Wash pluton were anomalous (Site No. 443). "Documents in the AZGS Documents Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact azgs-info@email.arizona.edu