Usage:
Stevens Ridge Formation (WA*)
Stevens Ridge Rhyodacite (WA)
Geologic age:
Miocene
Oligocene
Eocene*
Type section, locality, area and/or origin of name:
Named from Stevens Ridge, a prominent spur just north of Stevens Canyon in south-central part of Mount Rainier National Park, central WA. Crops out at many scattered localities in the park (Fiske and others, 1963).
AAPG geologic province:
Puget Sound 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 ([ ]).