Usage:
Yenruogis Member of St. Louis Formation (IA)
Geologic age:
Middle Mississippian (Visean; Meramecian)
Type section, locality, area and/or origin of name:
Type section: along south valley wall of Bridge Creek, in SE/4 NE/4 NE/4 sec. 22, T. 76 N., R. 12 W. (Van Buren Twp.), Keswick 7.5-min quadrangle, Keokuk Co., southeastern IA. Named from nearby Lake Yenruogis (Witzke and others, 1990).
AAPG geologic province:
Iowa shelf
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 ([ ]).