Usage:
Sinsinawa Member of Wise Lake Formation of Galena Group (IL,IA,MN)
Sinsinawa Member of Galena Dolomite of Sinnipee Group (WI)
Sinsinawa Member of Stewartville Formation of Galena Group (MN)
Subunits:
Dygerts Bentonite Bed (IL,IA,MN).
Geologic age:
Late Ordovician (Cincinnatian; Edenian)
Type section, locality, area and/or origin of name:
Type section: roadcut along U.S. Highway 20 on east side of Galena River at Galena, in SW/4 SE/4 NE/4 sec. 20, T. 28 N., R. 1 E., [approx. Lat. 42 deg. 24 min. 34 sec. N., Long. 90 deg. 25 min. 18 sec. W., Galena 7.5-min quadrangle], Jo Daviess Co., northwestern IL (Templeton and Willman, 1963, Illinois Geol. Survey Bull., no. 89, p. 126; Willman and Buschbach, 1975, Illinois Geol. Survey Bull., no. 95, p. 47-87)
Named from Sinsinawa River, [Galena 7.5-min quadrangle, Jo Daviess Co., northwestern IL, about 3 mi northwest of type section] (Templeton and Willman, 1963, p. 123; Willman and Buschbach, 1975).
Notable exposures in Dixon-Oregon area, northern IL (Templeton and Willman, 1952).
AAPG geologic province:
Iowa shelf
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 ([ ]).