Usage:
Gateway Pass unit (informal) in Castle Reef Formation of Madison Group (MT*)
Informal. The rank or lithologic term should not be capitalized.
Geologic age:
Middle Mississippian (Visean; late Osagean to Meramecian)*
Type section, locality, area and/or origin of name:
Named from Gateway Pass, in SE/4 sec. 14, T. 27 N., R. 11 W., Gateway Pass quadrangle, MT (Nichols, 1984).
Principal reference section: at North Fork Dupuyer Creek, in NW/4 NW/4 SW/4 sec. 21, T. 27 N., R. 9 W., Walling Reef quadrangle, MT (Nichols, 1984).
AAPG geologic province:
Sweetgrass arch*
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 ([ ]).