Usage:
Grassy Creek Shale (MO*)
Grassy Creek Member of Maple Mill Formation of Yellow Spring Group (IA)
Grassy Creek Shale Member of New Albany Shale of Knobs Group (IL-southern part)
Grassy Creek Member of New Albany Shale (KY)
[?] Grassy Creek Shale of New Albany Group (IL*)
Subunits:
MEMBER STATUS (alphaberical) all in IL[?]: Falling Run Bed, Henryville Bed, Jacobs Chapel Bed.
Geologic age:
Late Devonian (Famennian)*
Type section, locality, area and/or origin of name:
Type locality: Mississippi River bluff in Pike Co., northeastern MO, some distance above Champ Clark Bridge, in approx. SW/4 NW/4 NE/4 sec. 18, T. 54 N., R. 1 W. (Mehl, 1960).
Notable exposures on Grassy Creek in sec. 19 (Weller, 1935).
AAPG geologic province:
Illinois basin*
Iowa shelf
Lincoln anticline*
Ozark uplift*
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 ([ ]).