From abstract: During part of February and March 1953, reconnaissance examinations for radioactive material were made at 12 localities in the Yuma Air Force Base gunnery range in southern Yuma County, Ariz. The Yuma gunnery range, which is adjacent to the west edge of the Luke and Williams Air Force Bases gunnery range, is characterized by block faulted, elongate mountain ranges composed essentially of schist, gneiss, and granite of pre-Cambrian to Mesozoic age and separated by broad alluvial basins.

From introduction: This report is written in response to a request from the Army Engineers for an appraisal of the uranium potential of the area included in the Yams Test Station. the area of Proposed Expansion of the Yuma Test Station, and the Williams Bombing and Gunnery Range. Only the area covered by the present Yuma Test Station is included here. The other areas will be discussed In subsequent reports.

Summary and conclusion: More than 4000 feet of Lower Miocene lake sediments were deposited upon a gneissic basement rock, at least locally. The sediments have been gently folded into broad anticlines and synclines and have been cut by high-angle faults with displacements on the order of 100 feet. Both basaltic (?) and acid andesitic lavas have intruded the sediments. A Pleistocene (?) conglomerate unconformably overlies all older exposed rocks. The lake sediments were considered to overlie the adjacent thick series of andesite flows (l). This was not established by a cursory examination. The sediments appeared to be in fault contact with the lavas although the relationship was always obscured by the younger conglomerate or alluvial cover. Since a dike of this acid andesitic composition was observed cutting the sediments, there is a possibility that the lake sediments are older than or contemporaneous with the thick extrusive andesite series.

Report issued by the Bureau of Mines over tungsten deposits of Arizona. Characteristics of the tungsten deposits are discussed. This report includes tables, maps, and illustrations.