Pg. 11-12, pl. 1. Buzzard rhyolite of Ash Creek group. Outcrops in lower reaches of Black Canyon tinted in shades of red, whereas those in the headwaters are buff to cream. Contorted flow banding and amygdaloidal and vesicular structures common in flows. Fragmental structures common; some represent flow breccia. Thin sandy interbeds in breccia exposed near base of rhyolite west of Ward Pocket and 0.75 mile southeast of Allen Spring. Similar interbeds of sedimentary rock exposed near top of rhyolite north of Oak Wash. Megascopically rhyolitic rocks commonly porphyritic. Thickness of complete section in lower part of Black Canyon, where it overlies Gaddes basalt (new) and underlies Shea basalt, estimated at 3,500 feet. Age is Precambrian (Yavapai).
Good exposures in Buzzard Canyon, a tributary to Black Canyon, southeast of Mingus Mountain; [unnamed canyon in SW/4 SW/4 sec. 30, T. 15 N., R. 3 E., Cottonwood 7.5-min quadrangle, Yavapai Co., central AZ]. Excellent outcrops in Black Canyon, Jerome area, Yavapai Co., central AZ.

Source: US geologic names lexicon (USGS Bull. 1200, p. 561).