- Usage in publication:
-
- Marblemount quartz diorite
- Modifications:
-
- Original reference
- Dominant lithology:
-
- Quartz diorite
- AAPG geologic province:
-
- Northern Cascade Range-Okanagan province
Summary:
Pg. 4 (geol. map). Marblemount quartz diorite. Sheared and partly metamorphosed to chloritic schist. Earlier than Mesozoic folding. Older than Skagit gneisses. Age is pre-Mesozoic.
Marblemount is in Skagit Co., northwestern WA.
Source: US geologic names lexicon (USGS Bull. 1200, p. 2373).
- Usage in publication:
-
- Marblemount meta-quartz diorite
- Marblemount Belt quartz diorite gneiss
- Modifications:
-
- Geochronologic dating
- AAPG geologic province:
-
- Northern Cascade Range-Okanagan province
Summary:
Pg. 10. Marblemount meta-quartz diorite; Marblemount Belt quartz diorite gneiss. Samples from Skagit and Chelan Counties, northwestern Washington. U-Pb ages range from 243 to 215 Ma (zircon). [Age is Triassic.]
Source: GNC index card files (USGS-Menlo).
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 ([ ]).