Geologic Map of the Western Gila Bend and Southern Eagletail Mountains, Maricopa and Yuma Counties, Arizona

The area described in this study includes the western Gila Bend and the southern Eagletail mountains, Maricopa and La paz counties, Arizona. The study area encompasses all of the Columbus Peak Quadrangle (1:24,000) and the northern part of the Hyder Northeast Quadrangle (1:24,000), and is partially within the Eagletail Mountains Wilderness Area (Fig. 1). Bedrock in this area consists largely of scattered, limited exposures of Proterozoic to Jurassic metamorphic and igneous rocks intruded by a Miocene granitoid pluton and overlain by an extensive sequence of Miocene silicic volcanic rocks and subordinate mafic and intermediate volcanic units and continental clastic rocks (plate 1). Sources of data are shown in Figure 2, rock-unit correlations and relative ages are shown in Figure 3, and map symbols are shown in Table 1.