- Usage in publication:
-
- Center Grove Till Member
- Modifications:
-
- Named
- Dominant lithology:
-
- Till
- Silt
- AAPG geologic province:
-
- Illinois basin
Summary:
Named as member of Trafalgar Formation. Named for Center Grove School, Johnson Co., west-central IN. Consists of till, capped by a thin layer of silt through which modern soil profile extends where overlying Cartersburg Till Member is absent. Silt cap is a series of thin lenses of fossiliferous gray to brown silt that forms a key bed for identification of the top of the member in places where it underlies Cartersburg Till Member. Because it lies directly on a paleosol, contains a larger amount of wood fragments and weathered material than do other till units; locally they provide a distinctive lithology for the member. Age is Pleistocene (Wisconsin stage).
Source: GNU records (USGS DDS-6; Reston GNULEX).
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 ([ ]).