Geologic Map of the Fortuna 7.5' Quadrangle, Yuma County, Arizona, v. 1.0

This map depicts the geology of the Fortuna 7 ½' Quadrangle and about 2.5 square miles of the northern end of the Gila Mountains that is in the adjacent Laguna Dam, Dome, and Ligurta 7 ½' Quadrangles. The map area encompasses the northwestern Gila Mountains and the broad Gila River valley between the northern Gila Mountains and Yuma, in the southwestern corner of Arizona. The quadrangle covers bedrock in the northwestern Gila Mountains, much of the western piedmont at the foot of the northwestern Gila Mountains, and alluvial sediments deposited by the Gila and Colorado Rivers. Large, active gravel quarries, and the historic Dome placer gold district, are within the map area at the foot of the Gila Mountains. This mapping was completed under the joint State-Federal STATEMAP program, as specified in the National Geologic Mapping Act of 1992.