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Geologic map of the Hiller Mountain Quadrangle, Clark County, Nevada, and Mohave County, Arizona

February 14, 2003

Map Scale: 1:24,000
Map Type: colored geologic map
The Hiller Mountains Quadrangle straddles Virgin Canyon in the eastern part of Lake Mead. Proterozoic gneisses and granitoid rocks underlie much of the quadrangle. They are overlain by upper Miocene basin-filling deposits of arkosic conglomerate, basalt, and the overlying Hualapai Limestone. Inception of the Colorado River followed deposition of the Hualapai Limestone and caused incision of the older rocks. Fluvial gravel deposits indicate various courses of the early river across passes through highlands of the Gold Butte-Hiller Mountains-White Hills structural block. Faults and tilted rocks in the quadrangle record tectonic extension that climaxed in middle Miocene time.

Publication Year 2003
Title Geologic map of the Hiller Mountain Quadrangle, Clark County, Nevada, and Mohave County, Arizona
Authors Keith A. Howard, Simon Hook, Geoffrey A. Phelps, Debra L. Block
Publication Type Report
Publication Subtype Other Government Series
Index ID 70180947
Record Source USGS Publications Warehouse