Subsurface stratigraphy and geothermal resource potential of the Avra Valley, Pima County, Arizona

A subsurface stratigraphic study and preliminary investigation of the geothermal resource potential of the Avra Valley was undertaken in 1980. The area of investigation is situated in Pima County, Arizona, approximately five miles west of Tucson. The study area is bounded by 32 6' to 32 30' north latitude and 111 7' to 111 30' west longitude. Physiographically the area is bounded on the west by Ragged Top and Silver Bell mountains, the Waterman Mountains and the Roskruge Mountains. On the east side the area is bounded by the Tucson Mountains and the Tortolita Mountains. On the north the area is bounded by Cerro Prieto and the Marana Airpark and on the south by Dobbs Buttes and the San Xavier Indian Reservation. The study area comprises approximately 1575 square km. With the exception of the mining activities in the Silver Bell Mountains and the Twin Peaks area the primary business in the valley is agriculture, cotton farming and minor cattle production. The majority of the domestic and irrigation wells belonging to the town of Marana and the city of Tucson are between 91.4 m and 457.2 m deep. The Avra Valley is a major source of water of the city of Tucson. (48 pages)