Usage:
Cowen Member of Grand Detour Formation of Platteville Group (IL)
Geologic age:
Late Ordovician (Mohawkian; Turinian)
Type section, locality, area and/or origin of name:
Type section: Brookville northwest section, in quarry on north side of ravine northeast of U.S. Highway 52, in NE/4 SE/4 NW/4 sec. 21, T. 24 N., R. 7 E., Carroll Co., IL, 1.6 km northwest of Brookville, Ogle Co., IL (Willman and Kolata, 1978).
Named from Cowen School, 3.2 km southwest of type section (Willman and Kolata, 1978).
AAPG geologic province:
Wisconsin arch
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 ([ ]).