Usage:
Roughlock Siltstone (SD,WY)
Roughlock Siltstone Member of Winnipeg Formation (SD,WY)
Roughlock Formation of Winnipeg Group (ND)
Geologic age:
Late Ordovician (Mohawkian; Chatfieldian; Kirkfieldian to Shermanian)
Type section, locality, area and/or origin of name:
Type section: in Spearfish Canyon, 2.4 mi above Maurice, several hundred yards up canyon wall on east side of road towards Spearfish, in secs. 18 and 19, T. 5 N., R. 2 E., [Lawrence Co.], western SD (McCoy, 1958).
Named from Roughlock Falls along Little Spearfish Creek, in sec. 36, T. 5 N., R. 1 E. (McCoy, 1952).
AAPG geologic province:
Powder River basin
Williston 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 ([ ]).