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National Geologic Map Database

Geologic Unit: Big Valley

Usage:

Big Valley Formation of Three Forks Group (MT)
Big Valley Formation (MT)


Geologic age:

Late Devonian


Type section, locality, area and/or origin of name: (See Canadian Lexicon)

["Type section"] (subsurface): depth-interval 5,250 to 5,295 ft, Canadian Gulf Rumsey No. 6-30 well, LSD 6-30-33-21 West of 4th Meridian (W4M), Stettler area, Alberta, Canada (Wonfor and Andrichuk, 1956).


AAPG geologic province:

Williston 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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).