- Usage in publication:
-
- Wildcat Mountain Rhyolite
- Modifications:
-
- Named
- Dominant lithology:
-
- Rhyolite
- Tuff
- AAPG geologic province:
-
- Midcontinent region
Summary:
Wildcat Mountain Rhyolite. Unit is part of sequence of Precambrian volcanic rocks associated with Taum Sauk caldera in western part of St. Francois Mountains, southeast Missouri (Midcontinent region). Notable exposures on Bell, Crane, Lee, North Bell, Russell, Taum Sauk, and Wildcat Mountains, and College Hill. Consists of deep-maroon ash-flow tuff containing 5 to 10 percent quartz and feldspar phenocrysts and many white stringers of microcrystalline quartz and feldspar. Thickness 90 m. Overlies Russell Mountain Rhyolite (new); underlies Bell Mountain Rhyolite (new). Age is Precambrian. Report includes geologic map. Unit named and described on stratigraphic column (table 1).
Russell Mountain Rhyolite replaces: Hogan Mountain Rhyolite (Bell, Lee, North Bell, and Wildcat Mountains), Middlebrook Group (College Hill), and Stouts Creek Rhyolite (Crane, Russell, and Taum Sauk Mountains) as mapped by Tolman and Robertson (1969, Missouri Geol. Survey Rpt. Inv., no. 44); all but upper part of Unit D of tuff of Stouts Creek of Anderson (1970, Missouri Geol. Survey Rpt. Inv., no. 46); and Unit 780 of Berry and Bickford (1972, Bull. Volcanology, v. 36, p. 303-318).
Type section: in S/2 NE/4 sec. 6, T. 33 N., R. 3 E., Johnson Shut-ins quadrangle, MO. Named from exposures along north slope of Wildcat Mountain, Iron and Reynolds Cos., MO.
Source: Modified from GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Wildcat Mountain Rhyolite
- Modifications:
-
- Revised
- AAPG geologic province:
-
- Midcontinent region
Summary:
Wildcat Mountain Rhyolite, 8th formation from base (of 12) of /Taum Sauk Group (new) of /St. Francois Mountains Volcanic Supergroup (revised). Study area is St. Francois Mountains, southeast Missouri (Midcontinent region). Overlies Russell Mountain Rhyolite (revised) of Taum Sauk; underlies Bell Mountain Rhyolite (revised) of Taum Sauk. Age is Precambrian Y. Nomenclature listed in table 1.
[Conflicts with nomenclature guidelines (ACSN, 1970; NACSN, 1983, 2005, 2021): name Taum Sauk used for both group and formation within it (Taum Sauk Rhyolite has priority); name St. Francois Mountains applied concurrently to two different units in same area; a [supergroup] name combines a geographic name with the term ["supergroup,"] and no lithic designation is included.]
Source: Modified from 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 ([ ]).