Usage:
Peerless Formation (CO*)
Peerless Dolomite (CO*)
Peerless Formation of Horseshoe Mountain Group (CO)
Geologic age:
Late Cambrian (Franconian)*
Type section, locality, area and/or origin of name:
Typical occurrence on northwest slope of Peerless Mountain, 6 mi east-southeast of Leadville, Lake and Park Cos., Mosquito Range, central CO (Behre, 1932).
AAPG geologic province:
Denver basin*
Eagle basin*
South Park 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 ([ ]).