Arizona Geological Survey

Map of Arizona geologic hazards

This geologic map was produced to compile and reinterpret published geologic information, and present the result of new geologic mapping in the Ray-Superior area. This data set serves as the basis for ongoing efforts to better understand the geologic history of this area, particularly with respect to the distribution and origin of mineral deposits.

Horseshoe and Bartlett Dams are located In the Transition Zone of central Arizona. Within this province, faults with evidence of Quaternary activity are widely scattered, and selsmiclty Is low In comparison to other parts of the western United States.

This report presents an assessment of the seismic hazard associated with the Sugarloaf fault, which crosses State Route (SR) 87 near Mesquite Wash in central Arizona. The Sugarloaf fault is a 20 km (12 mile) long, northwest- to north-trending normal fault with displacement down to the east. We conducted a multi-faceted investigation in order to evaluate the late Quaternary behavior of the Sugarloaf fault and assess the seismic hazard associated with it.