Usage:
Blackford Formation (GA,TN,VA*,WV*)
Blackford Formation of Chickamauga Group (TN)
Geologic age:
latest Middle and/or earliest Late Ordovician (Chazyan)*
Type section, locality, area and/or origin of name:
Notable exposures along U.S. Route 19 at several places between Pounding Mill Branch and Pisgah Chapel, Tazewell Co., southwestern VA and near Blackford, Russell Co., southwestern VA (Butts, 1940).
AAPG geologic province:
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 ([ ]).