Usage:
Elephant Mountain Member of Saddle Mountains Basalt of Columbia River Basalt Group (ID*,OR*,WA*)
Elephant Mountain Member of Saddle Mountains 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).]
Geologic age:
late Tertiary (middle to late Miocene)*
Type section, locality, area and/or origin of name:
Type locality: south of Elephant Mountain, along eastern continuation of Rattlesnake Ridge, about 16 km southeast of Yakima, chiefly in secs. 22 and 27, T. 12 N., R. 20 E., Elephant Mountain quadrangle, Yakima Co., south-central WA (Waters, 1955; Swanson and others, 1979).
Reference locality: Ward Gap, 6.5 km west of Prosser, in NE/4 SE/4 sec. 20, T. 8 N., R. 24 E., Prosser quadrangle, Benton 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 ([ ]).