Anvil Rock Sandstone Member of Shelburn Formation of McLeansboro Group (IL*,KY*)
Anvil Rock Sandstone Member of Dugger Formation of Carbondale Group (IN*)
Middle Pennsylvanian (Moscovian; Westphalian D; Desmoinesian)*
Named from bluff known as Anvil Rock [southwest of Henshaw near Ohio River] in Union Co., west-central KY (Owen, 1856).
Illinois 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 ([ ]).