ECONOMIC GEOLOGY OF THE DRIPPING SPRINGS AREA, SAN CARLOS APACHE INDIAN RESERVATION, CENTRAL ARIZONA

The Dripping Springs copper prospect on the San Carlos Apache Indian Reservation contains weak, vein-related Cu-Au mineralization and unexplained geophysical anomalies which suggest the presence of a buried porphyry copper target. Geological mapping and re-examination of geochemical and geophysical data lead to the siting of five diamond drill holes to test the area’s potential. The drilling did not detect a porphyry copper system. Drilling results indicate that the geophysical anomalies can be explained by previously unrecognized structural displacement of the Precambrian and Paleozoic sequence along post-Laramide, high-angle normal faults. The low-angle structures previously interpreted in the area appear not to be present. The drilling did locate potentially important water resources. Mapping has confirmed the presence of significant aggregate and limestone resources in the Dripping Springs area.