Usage:
Argo-Fay Bed of Scales Formation of Maquoketa Group (IL-recognized locally in Carroll Co.)
Geologic age:
Late Ordovician
Type section, locality, area and/or origin of name:
Type section: Mt. Carroll southwest section, in quarry on the north side of U.S. Highway 52, 2.5 mi southwest of Mt. Carroll and 5 mi north of Argo-Fay, in SW/4 NE/4 SW/4 sec. 10, T. 24 N., R. 4 E., Savanna 15-min quadrangle, Carroll Co., IL (Kolata and Graese, 1983).
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 ([ ]).