No current usage?
(†Tassai Wash Group (AZ) considered abandoned? Uncertain if used by the AZ Geol. Survey. Not used by the USGS.)
Tertiary
Not designated. Named from Tassai Wash, northeast of Grand Wash, Mohave Co., AZ (Longwell, 1936).
Plateau sedimentary 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 ([ ]).