- Usage in publication:
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- Clifford Creek Granite*
- Modifications:
-
- Named
- Dominant lithology:
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- Granite
- AAPG geologic province:
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- Montana folded belt
Summary:
Named for Clifford Creek, northwest of Black Lion Mountain, Stine Mountain, and Vipond Park quads, Beaverhead Co, MT in Montana folded belt province. These exposures are designated the type locality. Is a two-mica, massive, coarse, gray granite and porphyritic, coarse granite. Is one of five plutonic units of Pioneer batholith. Has biotite K-Ar age of 64.6 +/-2.1 and 64.9 +/-2.2 m.y., and a biotite 40 Ar/39 Ar of 65.6 +/-l.4 m.y. -or Late Cretaceous and Paleocene.
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 ([ ]).