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.

From summary: The objective of the project was to obtain subsurface data that would permit a more accurate estimate to be made of the uranium potential in the Tertiary basins within the project area.

Supplementary data containing geophysical drilling logs to accompany an engineering report on drilling in the Western Prescott and Williams Quadrangles, Arizona.