Field, J.J., and Pearthree, P.A., 1993, Surficial geologic maps of the northern Avra Valley - Desert Peak area, Pinal and Pima Counties, southern Arizona [Picacho Pass, Durham Hills, Chief Butte, Samaniego Hills, Red Rock, Desert Peak, Tortolita Mts., Silver Bell East, and West of Marana 7.5 min]: Arizona Geological Survey Open-File Report 93-13, 11 p., 9 sheets, scale 1:24,000.
