Usage:
Vaughn Member of Blackleaf Formation of Colorado Group (MT*)
Vaughn Member of Mowry Shale (MT*)
Geologic age:
early Late Cretaceous (Cenomanian)*
Type section, locality, area and/or origin of name:
Type section: 3.5 mi northeast of Vaughn in south-facing bluffs, in NE/4 sec. 6, T. 21 N., R. 2 E., and SE/4 sec. 31, T. 22 N., R. 1 E., Cascade Co., MT. Named from town of Vaughn, in sec. 24, T. 21 N., R. 1 E., Cascade Co., MT (Cobban and others, 1959).
Principal reference section: in W/2 NE/4 sec. 7, T. 9 S., R. 4 E., Gallatin Co., MT (Tysdal and others, 1989).
Reference section (composite); type is inaccessible: in secs. 31 and 32, T. 22 N., R. 2 E., to NE corner sec. 6, T. 21 N., R. 2 E. (Cobban and others, 1976).
AAPG geologic province:
Sweetgrass arch*
Snake River basin*
Montana folded belt*
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 ([ ]).