- Usage in publication:
-
- Ramp Creek member
- Modifications:
-
- Named
- Dominant lithology:
-
- Limestone
- Chert
- AAPG geologic province:
-
- Illinois basin
Summary:
Basal member of Harrodsburg limestone in southern IN here named Ramp Creek member. Described as variably siliceous limestone with irregularly distributed crinoid lenses, and characterized by prevalence of geodes and chert. Thickness 16 to 28 ft. Underlies Leesville limestone member and overlies Borden group.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Ramp Creek Formation
- Modifications:
-
- Biostratigraphic dating
- AAPG geologic province:
-
- Illinois basin
Summary:
Occurrence of two key brachiopod species in the Ramp Creek Formation and Harrodsburg Limestone in south-central IN indicates boundary between the Osagean and Meramecian Series lies in the lower part of the Ramp Creek Formation. MARGINIRUGUS MAGNUS (Meek and Worthen), an Osagean index fossil is found in the lower part of the Ramp Creek. WARSAWIA LATERALIS (Hall), a Meramecian index fossil also occurs in the lower part of the Ramp Creek and in the lower part of the overlying Harrodsburg.
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 ([ ]).