No current usage.
(†Tornado Limestone (AZ) replaced with Escabrosa Limestone and Naco Limestone. See Escabrosa and Naco.)
Mississippian
Pennsylvanian
Not designated. Named from Tornado Peak, Dripping Spring Range, Ray quadrangle, Gila Co., central AZ (Ransome, 1919).
Basin-and-Range province
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).