Lava Creek Tuff of Yellowstone Group (ID*,MT*,WY*)
Lava Creek A ash (informal) (WY*)
Lava Creek B ash (informal) (CA*,CO*,ID*,IA*,KS*,MT*,NE*,NV*,NM*,OK*,SD*,TX*,UT*,WY*,Canada)
Lava Creek A ash is downwind equivalent of member A of Lava Creek Tuff.
Lava Creek B ash is downwind equivalent of member B of Lava Creek Tuff (previously called Pearlette type O ash bed).
For informal usage, the rank or lithologic term should not be capitalized.
Type area: Upper Canyon of Lava Creek, and its tributary, Arrow Canyon, in Yellowstone National Park, Park Co., WY. Named from Lava Creek (Christiansen and Blank, 1972).
Principal reference sections: (1) lower informal member in south-facing cliff of Purple Mountain, above old gravel pit, about 1 km east of Madison Junction; (2) upper informal member in east wall of Sheepeater Canyon, Garder River, 1 km northeast of Osprey Falls (Christiansen and Blank, 1972).
Central Kansas uplift*
Central Western Overthrust*
Great Basin province*
Green River basin*
Gulf Coast basin*
Las Vegas-Raton basin*
Los Angeles basin*
Palo Duro basin*
Plateau sedimentary province*
Powder River basin*
San Juan basin*
San Juan Mountains province*
Sierra Grande uplift*
Snake River basin*
South Western Overthrust*
Wind River basin*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.
"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).