Pacific Creek Tuff Member of Trout Peak Trachyandesite of Sunlight Group of Absaroka Volcanic Supergroup (WY*)
early Tertiary (Eocene)*
Type area: Pacific Creek, near Two Ocean Pass, Yellowstone National Park, WY (Smedes and Prostka, 1972).
Yellowstone 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 ([ ]).