- Usage in publication:
-
- Pond Spring Formation
- Modifications:
-
- Named
- Dominant lithology:
-
- Limestone
- AAPG geologic province:
-
- Appalachian basin
Summary:
Named Pond Spring Formation to replace "Newala" of Butts and Gildersleeve (1948) in the type area of the Chickamauga Supergroup. The Pond Spring can be divided into three informal members (lower, middle, upper). The lower member is 140-170 feet thick and consists of an upward sequence of conglomerate-red beds, calcilutite, and red beds. The middle member is 60 feet thick and consists of thick-bedded gray calcilutite and calcisiltite. The upper member is 70 feet thick and consists of argillaceous calcisiltite that weathers to mudstone and shale. The entire Pond Spring Formation is 250-300 feet thick and unconformably overlies the Knox Group and underlies the Murfreesboro Limestone. Unit is considered to be of Middle Ordovician age.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Pond Spring Formation*
- Modifications:
-
- Adopted
- Areal extent
- AAPG geologic province:
-
- Appalachian basin
Summary:
The Pond Spring Formation of Milici and Smith (1969) of the Stones River Group in the Chickamauga terrane in GA is here accepted for USGS use. It is the lowest unit of the Stones River; unconformably overlies the Knox Group and underlies the Murfreesboro Limestone. Age is Middle Ordovician.
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 ([ ]).