- Usage in publication:
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- Beaverhead granite
- Modifications:
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- Original reference
- Dominant lithology:
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- Granite
- AAPG geologic province:
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- Montana folded belt
- Idaho Mountains province
Summary:
Pg. 370-372, pl. 1. Beaverhead granite. Moderately coarse-grained granite ranging from light gray to pink and light green. Cut by coarse quartz veins and small aplite dikes of same composition as main body but of much finer texture. More than 6 miles long and 2 miles wide in outcrop. Underlies Medicine Lodge volcanics (new). Age is Eocene.
Crops out in Beaverhead Range along ID-MT state line. Described from occurrences in Beaverhead Co., southwestern MT. Extends into east-central ID.
Source: US geologic names lexicon (USGS Bull. 1200, p. 261).
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 ([ ]).