Geologic Map of the North Butte Area, Central Arizona

The North Butte area was mapped during the 1995-1996 winter field season as part of the Arizona Geologic Survey mapping program to complete the Mesa 30 by 60 minute quadrangle. The area is one of extensive low relief pediments cut on Proterozoic and Laramide granitoid, and Tertiary conglomerate. North and South Butte are the major physiographic features of the area, both underlain by Tertiary felsic lavas. Rugged terrain is also present in the northeastern part ofthe map area, underlain by Tertiary hypabyssal rhyolite intrusions. Surficial geology of the North Butte Quadrangle was mapped by Huckleberry [1993], and the interested reader is referred to this map for more information on the surficial geology. Access to the area is via a good graded dirt road that connects Cochran with the Florence-Kelvin road, roads along the north and south side of the Gila River as far east as the west side of North or South Butte respectively, and a four-wheel-drive jeep trail into the northeastern part of the map area, north of the Gila River, that is accessed southwest from the Walnut Canyon Road in the Teapot Mountain Quadrangle. Donnelly Wash and Box '0' washes are both passable in a four-wheel-drive vehicle. Box '0' Wash cannot be traversed from the Florence-Kelvin Road all the way to the Gila River because of fenced private land near the south edge of the map area.