Usage:
Wanapum Basalt of Columbia River Basalt Group (ID*,OR*,WA*)
Wanapum Basalt of /Yakima basalt subgroup [informal] of Columbia River Basalt Group (ID*,OR*,WA*)
[Yakima basalt subgroup considered informal and should not be capitalized. "Subgroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). Columbia River Basalt Group adopted by the ID, OR, and WA Geol. Surveys, and the USGS (rules suspended).]
Subunits:
(alphabetical): Eckler Mountain Member (OR*,WA*), Frenchman Springs Member (OR*,WA*), Onaway Member (ID,WA), Priest Rapids Member (ID*,OR*,WA*), Roza Member (OR*,WA*).
Geologic age:
late Tertiary (middle Miocene)*
Type section, locality, area and/or origin of name:
Type locality: exposure along east side of Columbia River near Wanapum Dam, from Sand Hollow in sec. 28, T. 17 N., R. 23 E., south to near Vantage Substation above Wanapum Dam, in sec. 16, T. 16 N., R. 23 E., Vantage and Beverly quadrangles, Grant Co., WA (Swanson and others, 1979).
AAPG geologic province:
Eastern Columbia basin*
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 ([ ]).