- Usage in publication:
-
- Bonanza Orthogneiss
- Modifications:
-
- Areal extent
- Dominant lithology:
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- Gneiss
- AAPG geologic province:
-
- Cascades province
Summary:
Pg. 292 (footnote). Skagit Gneiss (Misch, 1952) has been restricted by Misch (ms) to include gneisses that can be demonstrated to be products of migmatization of sedimentary-volcanic sequence, and gneisses of doubtful origin. All the gneisses that can be shown to be derived from plutonic rocks are now separated from Skagit Gneiss (restricted). They include: Eldorado Orthogneiss, Gabriel Peak Orthogneiss, Bonanza Orthogneiss. [Age not stated by author.]
[Probably named from Bonanza Peak, northern Chelan Co., north-central WA.]
Source: US geologic names lexicon (USGS Bull. 1350, p. 82); GNU records (USGS DDS-6; Menlo 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 ([ ]).