Usage:
Lithograph City Formation of Cedar Valley Group (IL,IA,MN,MO)
Subunits:
(alphabetical): Andalusia Member (IL,IA,MO), Idlewild Member (IA,MN), Osage Springs Member (IA), State Quarry Member (IA), Thunder Woman Shale Member (IA).
Geologic age:
late Middle to early Late Devonian (Givetian to Frasnian)
Type section, locality, area and/or origin of name:
Old quarry adjacent to former town of Lithograph City, in SW/4 NE/4 sec. 26, T. 97 N., R. 17 W., Floyd Co., IA. Only Idlewild Member is present (Bunker and others, 1986; Witzke and others, 1988).
Complete reference section (subsurface): in FM-4 core, in SW/4 NW/4 SE/4 sec. 31, T. 96 N., R. 18 W., [Floyd Co., IA] (Witzke and others, 1988).
AAPG geologic province:
Iowa shelf
Lincoln anticline
Illinois basin
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 ([ ]).