Usage:
Arapahoe Formation (CO*)
Arapahoe conglomerate (informal, unranked) of Denver Basin Group (CO-subsurface)
For informal, unranked usage, the lithologic term should not be capitalized.
Geologic age:
Late Cretaceous*
Type section, locality, area and/or origin of name:
Named from development in Arapahoe Co., Denver basin, eastern CO (US geologic names lexicons, USGS Bull. 896, 1200).
AAPG geologic province:
Denver 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 ([ ]).