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National Geologic Map Database

Geologic Unit: Twin Creek

Usage:

Twin Creek Limestone (ID,UT*,WY)
Twin Creek Formation (ID*,UT*,WY*)


Subunits:

(alphabetical): Boundary Ridge Member (ID*,UT*,WY*), Giraffe Creek Member (ID*,UT*,WY*), Gypsum Spring Member (ID*,UT*,WY*), Leeds Creek Limestone Member (UT*) or Leeds Creek Member (ID*,UT*,WY*), Rich Member (ID*,UT*,WY*), Sliderock Member (ID*,UT*,WY*), Watton Canyon Member (ID*,WY*).


Geologic age:

Jurassic, Middle*
Bajocian*
Bathonian*
Callovian*


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

Not designated. Named from exposures along Twin Creek, in secs. 1, 12, and 18, T. 21 N., R. 120 W., Lincoln Co., WY (Veatch, 1907).


AAPG geologic province:

Uinta uplift*
Uinta basin*
Yellowstone province*
Snake River basin*
Green River basin*
Great Basin province*
Wasatch uplift*


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 ([ ]).