Usage:
Arsenal Member of Oneota Dolomite of Prairie du Chien Group (IL-notably in northern part)
Geologic age:
Early Ordovician (Canadian; Ibexian; Tremadocian; Skullrockian)
Type section, locality, area and/or origin of name:
Type section (subsurface): depth-interval 980 to 1,085 ft, Layne-Western Kankakee No. 9 well, in sec. 25, T. 34 N., R. 9 E., Will Co., northeastern IL. Named from Joliet Arsenal in western Will Co. (Buschbach, 1964).
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 ([ ]).