Geologic map of Sam Powell Peak 7.5' Quadrangle, Yavapai County, Arizona

This geologic map is one of a series of four 7 ½’ quadrangle maps (AZGS DGM-131 through 134; Wickenburg, Sam Powell Peak, Flores, and Vulture Peak) in the Wickenburg area. New surficial mapping was conducted throughout the 4-quadrangle mapping area and bedrock mapping was compiled from existing geologic maps, with new bedrock mapping in Sam Powell Peak. Together, these maps include detailed surficial mapping of alluvium from the Date Creek, Weaver, Wickenburg, and Vulture Mountains as well as ancestral deposits of the Hassayampa River. The relationships between relict and modern alluvial fan and Hassayampa River deposits and their positions relative to pre-existing bedrock topography presents a glimpse into the arrival and development of the modern Hassayampa River system. The Sam Powell Peak 7 ½' Quadrangle is located north of the town of Wickenburg and southeast of the town Congress in Yavapai County, Arizona. A system of interconnected dirt roads connects the map area to the town of Wickenburg and US Highway 93 to the south, and AZ Highway 89 to the west: Scenic Loop road, Stanton Hall road, and Angels Ranch road. Most of the mapping area is owned by State Trust lands and Bureau of Land Management (BLM) with minor private lands. The Hassayampa River Canyon Wilderness area along the Hassayampa and Sam Powell Peak areas is managed by BLM. Bedrock in the southern half of Sam Powell Peak quadrangle was mapped separately as part of the EDMAP grant (award no. G18AC00230). The main focus of surficial mapping in the Sam Powell Peak quadrangle was Neogene and Quaternary basin-fill deposits, Hassayampa River deposits, and tributary deposits. The Hassayampa River flows between the Weaver Mountains (and its namesake Sam Powell Peak) to the north and northwest, the Wickenburg Mountains to the east, across the Black Hills to the south, and an unnamed topographic ridge and hydrologic boundary to the west. The intervening valley between these topographic highs is informally referred to as the “Sam Powell basin”. Bedrock mapping focused on highly extended mid-Cenozoic volcanic and sedimentary rocks and their underlying Proterozoic and Laramide crystalline basement.