- Usage in publication:
-
- Yakima Basalt*
- Modifications:
-
- Geochronologic dating
- AAPG geologic province:
-
- Snake River basin
Summary:
Pg. 235. Yakima Basalt of Columbia River Group. Sample from Yakima petrologic type basalt near Hornet Reservoir, north of Weiser, [Washington Co.], western Snake River Plain, southern ID,, yielded a K-Ar age of 17 +/-1.5 Ma (whole-rock); middle Miocene (Evernden and others, 1964, Amer. Jour. Sci., v. 262, p. 145-198). Report includes sample locality map, schematic stratigraphic-chronologic diagram, table of K-Ar ages.
Source: Publication.
- Usage in publication:
-
- Yakima Basalt subgroup [informal]*
- Modifications:
-
- Revised
- Age modified
- Areal extent
- AAPG geologic province:
-
- Eastern Columbia basin
Summary:
Yakima basalt subgroup [informal] of Columbia River Basalt Group. Divided into three formations (ascending): Grande Ronde Basalt, Wanapum Basalt, and Saddle Mountains Basalt. Geographically extended from southern Washington and northern Oregon into northwestern Idaho. Overlies Picture Gorge Basalt of Columbia River Group. Age changed from middle and late Miocene and early Pliocene --to-- early, middle, and late Miocene.
[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.]
Source: Publication; Changes in stratigraphic nomenclature, 1979 (USGS Bull. 1502-A, p. A85-A86).
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 ([ ]).