Usage:
Yampa Bed of Williams Fork Formation of Mesaverde Group (CO)
Geologic age:
Late Cretaceous
Type section, locality, area and/or origin of name:
Type section: measured in NE/4SW/4 sec. 6, T. 5 N., R. 91 W., about 8 mi south of Craig, Moffat Co., CO. Named from exposures in the Yampa, Danforth Hills, and Grand Hogback coal fields, Moffat and Routt Counties, northwestern CO. Named from Yampa River valley (Brownfield and Johnson, 2008).
AAPG geologic province:
Green River basin
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 ([ ]).