- Usage in publication:
-
- Umbrella Butte Formation*
- Modifications:
-
- [Principal reference]
- Dominant lithology:
-
- Quartzite
- Conglomerate
- AAPG geologic province:
-
- Idaho Mountains province
Summary:
Pgs. 9 (fig. A5), 10 (fig. A6), 14, 60, pls. 1, 2 (geologic map). Umbrella Butte Formation of Windermere Supergroup. [See also entry under Windermere.] Quartzite, quartzite-pebble conglomerate, and minor sillimanite-biotite-quartz schist and marble. Estimated thickness about 1,500 m [4,900+ feet] in Gospel Peaks roof pendant. Exposures are discontinuous along a southeastern trend across central Idaho. Is top formation of Windermere Supergroup in study area. Unconformably(?) overlies Missouri Ridge Formation (new) of Windermere Supergroup. Age is Neoproterozoic and Cambrian(?).
Type section: exposures at Umbrella Butte in Gospel Peaks roof pendant, Hanover Mountain 7.5-min quadrangle, Idaho Co., [Nez Perce National Forest], west-central ID (Lund, 2004, fig. A6, loc. 3).
Named from Umbrella Butte, [in SW/4 sec. 15, T. 26 N., R. 4 E., Lat. 45 deg. 35 min. 11 sec. N., Long. 115 deg. 57 min. 10 sec. W.], Hanover Mountain 7.5-min quadrangle, Idaho Co., [Nez Perce National Forest], west-central ID (Lund, 2004).
[Additional locality information from USGS historical topographic map collection TopoView and USGS GNIS database, accessed January 31, 2025.]
Source: Publication.
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 ([ ]).