Geologic Map of the Southern Part of the Union Pass 7 ½’ Quadrangle, Mohave County, Arizona

This map depicts the bedrock and surficial geology of much of the Union Pass quadrangle in the Black Mountains and the lower Colorado River Valley, Mohave County, northwestern Arizona. The geologic mapping is original but was informed by extensive previous mapping in the lower Colorado River Valley by AZGS geologists. This geologic map complements 11 previous Arizona Geological Survey 7 ½ ‘quadrangle mapping projects in this area, and the geologic map of the Secret Pass quadrangle immediately to the east (Ferguson et al., in prep.).