- Usage in publication:
-
- Firehole Bed*
- Modifications:
-
- Named
- Dominant lithology:
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- Tuff
- AAPG geologic province:
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- Green River basin
Summary:
Named as a bed, a conspicuous marker, in the Wilkins Peak Member of the Green River Formation for exposures in Little, Middle, and South Firehole Canyons, Ts16 and 17N, Rs106 and 107W, Sweetwater Co, WY in the Greater Green River basin. Was designated "first tuff" by Culbertson (1961). Consists of very hard, massive, rusty-brown weathering tuff. Consists of analcite, lesser amount of authigenic euhedral albite? or other feldspar, and some pyrrhotite. Crops out as a ledge. Breaks into angular blocks which make a conspicuous litter downslope from outcrops. Is 0.4 ft thick in section measured in sec 10, T17N, R106W where it lies about 95 ft above base of Wilkins Peak. Ranges from 3 inches to 1 ft throughout a distance of 30 mi along the outcrop. Recognized in cores. Overlies and underlies unnamed parts of Wilkins Peak. Of Eocene age. Geologic map; stratigraphic table.
Source: GNU records (USGS DDS-6; Denver GNULEX).
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 ([ ]).