Lexicon of geologic names of southern Arizona
— Larry Mayer

The entries in this lexicon are organized as follows: Geologic Name Thickness Geologic Period

Geologic names include informal names as well as names accepted by the U.S. Geological Survey. Thickness refers to the type section. If a type section was not referred to in the source, then the maximum thickness was used. All localities are in southeastern Arizona unless otherwise indicated. The source of the isotopic age-dates are referenced only when they were not contained in the source noted in item 2. A "t" after a geologic name indicates the name is generally unused or obsolete.

I would like to thank George Davis, Wesley H. Peirce, Steve Reynolds and Jan C. Wilt for reviewing an earlier draft of the manuscript. Special thanks to Stan B. Keith for his most useful and informative comments.