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National Geologic Map Database

Geologic Unit: Chugwater

Usage:

Chugwater Group (CO*,WY*)
Chugwater Formation (CO*,WY*,MT*)


Subunits:

GROUP STATUS (alphabetical): Alcova Limestone (WY*), Crow Mountain Sandstone (WY*), Jelm Formation (CO*,WY*), Popo Agie Formation (WY*), Red Peak Formation (CO*,WY*).
FORMATION STATUS (alphabetical): Alcova Limestone (WY*), Crow Mountain Sandstone Member (WY), Popo Agie Member (WY*), Red Peak Member (CO*,WY*).


Geologic age:

Triassic*


Type section, locality, area and/or origin of name:

Named from Chugwater Creek near Iron Mountain, [Platte Co.], WY (Darton, 1904).


AAPG geologic province:

Bighorn basin*
Denver basin*
Green River basin*
Powder River basin*
Wind River basin*
Yellowstone 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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).