No current usage.
(Rocks of †Hignite Formation of Breathitt Group (KY*,TN*) reallocated to Breathitt Formation [or /Four Corners Formation of Breathitt Group] in KY, and to Vowell Mountain and Redoak Mountain Formations in TN. See Breathitt, Four Corners, Redoak Mountain, and Vowell Mountain.)
[Four Corners Formation conflicts with nomenclature guidelines (NACSN, 1983, 2005, 2021).]
Middle Pennsylvanian (early Moscovian; Westphalian B; middle Atokan)
Named from Hignite Creek, near Middlesboro, Bell Co., 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 ([ ]).