Usage:
Elkport Bentonite Bed of Glenhaven 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: Guttenberg north section, roadcut on U.S. Highway 52 northwest of Guttenberg, in SW/4 SW/4 sec. 5, T. 92 N., R. 2 W., Clayton Co., northeast IA. Named from town of Elkport, 14.5 km southwest of type section (Willman and Kolata, 1978).
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 ([ ]).