- Usage in publication:
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- Bridgerian age
- Modifications:
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- Original reference
- AAPG geologic province:
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- Green River basin
Summary:
Pg. 10, pl. 1. Bridgerian age. Provincial time term, based on the Bridger formation of southwestern Wyoming (of a redefinition of Bridgerian "series" of C.R. Keyes), or more specifically, the time of deposition of Blacks Fork and Twin Buttes members of Bridger formation (Eocene) with enclosed faunas. Covers time interval between Eocene Wasatchian (older) and Uintan ages. [In lower to middle part of Eocene; = OROHIPPUS faunal zone.] Report defines 18 provincial time terms, based on mammal-bearing units, for North American continental Tertiary. [For sequence see under Puercan.]
Source: US geologic names lexicon (USGS Bull. 1200, p. 475).
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 ([ ]).