No current usage.
(Rocks of †Red Spring Sandstone Member of †Hignite Formation (KY*,TN*) reallocated to Breathitt Formation [or /Four Corners Formation of Breathitt Group] in KY, and to Vowell Mountain Formation in TN. See Breathitt, Four Corners, and Vowell Mountain.)
[Four Corners Formation conflicts with nomenclature guidelines (NACSN, 1983, 2005, 2021).]
Middle Pennsylvanian (early Moscovian; Westphalian B; middle Atokan)
Named from its association with Red Spring coal [now called Red Springs] in Cumberland Gap coal field, southeastern KY (US geologic names lexicons, USGS Bull. 896, 1200).
Appalachian 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 ([ ]).