Usage:
Garnavillo Member of Guttenberg Formation of Galena Group (IL,IA,WI)
Geologic age:
Late Ordovician (Mohawkian; Chatfieldian)
Type section, locality, area and/or origin of name:
Type section: roadcut of U.S. Highway 52 on northwest side of Guttenberg, in SW/4 SW/4 sec. 5, T. 92 N., R. 2 W., [approx. Lat. 42 deg. 48 min. 24 sec. N., Long. 91 deg. 06 min. 32 sec. W., Guttenberg 7.5-min quadrangle], Clayton Co., eastern IA (Templeton and Willman, 1963, Illinois Geol. Survey Bull., no. 89, p. 113; Willman and Buschbach, 1975, Illinois Geol. Survey Bull., no. 95, p. 47-87).
Named from Garnavillo, [Garnavillo 7.5-min quadrangle], Clayton Co., eastern IA, 7.5 mi northwest of type section (Templeton and Willman, 1963, p. 113; 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 ([ ]).