Usage:
Winthrop Formation of Pasayten Group (WA)
Winthrop Formation (WA)
Winthrop Sandstone (WA)
Geologic age:
Late Cretaceous
Type section, locality, area and/or origin of name:
On northeast side of State Highway 20, between 5 and 6 mi northwest of Winthrop, in secs.13 and 14, T. 35 N., R. 20 E. [northeastern part of Mazama 15-min quadrangle, Okanogan Co.] WA (Barksdale, 1975).
AAPG geologic province:
Northern Cascade Range-Okanagan 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 ([ ]).