Usage:
Clement 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: in a ravine 0.5 mi north of village of Zell, in W/4 sec. 34, T. 38 N., R. 8 E., [approx. Lat. 37 deg. 57 min. 27 sec. N., Long. 90 deg. 08 min. 36 sec. W., Weingarten 7.5-min quadrangle], Ste. Genevieve Co., southeastern MO (Templeton and Willman, 1963, Illinois Geol. Survey Bull., no. 89, p. 86; Willman and Buschbach, 1975, Illinois Geol. Survey Bull., no. 95, p. 47-87).
Named from Clement Station on San Francisco Line, along Establishment Creek, [approx. Lat. 38 deg. 03 min. 24 sec. N., Long. 90 deg. 09 min. 52 sec. W., Bloomsdale 7.5-min quadrangle], Ste. Genevieve Co., southeastern MO, 7 mi north of type section (Templeton and Willman, 1963, p. 119; Willman and Buschbach, 1975).
Notable exposures in Dixon-Oregon area, northern IL (Templeton and Willman, 1952).
AAPG geologic province:
Illinois basin
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 ([ ]).