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National Geologic Map Database

Geologic Unit: Pond Ridge

Usage:

Pond Ridge Rhyolite of /Taum Sauk Group of /St. Francois Mountains Volcanic Supergroup (MO-recognized locally in St. Francois Mountains area)

[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 (see ACSN, 1970; NACSN, 1983, 2005).]


Geologic age:

Precambrian


Type section, locality, area and/or origin of name:

Type section: in NE/4 NW/4 sec. 3, T. 33 N., R. 3 E., Ironton quadrangle, Iron Co., MO. Origin of name not stated by author, but probably named from ridge south of Graniteville, Iron Co., MO (Berry, 1976).


AAPG geologic province:

Midcontinent region


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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).