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National Geologic Map Database

Geologic Unit: Snowy Range

Usage:

Snowy Range Formation of Gallatin Group (MT*,WY*)
Snowy Range Formation (MT)


Subunits:

FORMATION STATUS (alphabetical): Dry Creek Shale Member (MT*,WY*) or Dry Creek Member (MT), Grove Creek Limestone Member (MT*,WY*), Sage Limestone Member (MT*,WY*) or Sage Member (MT).


Geologic age:

Late Cambrian to Early Ordovician*


Type section, locality, area and/or origin of name:

Type locality: on south slope of Castle Rock, about 2 mi downstream from ranch at junction of East Fork with Mill Creek, Park Co., MT. Section measured in N/2 SE/4 sec. 13, T. 6 S., R. 9 E. (Dorf and Lochman, 1940).


AAPG geologic province:

Bighorn basin
Central Montana uplift
Montana folded belt*
Snake River basin*
Sweetgrass arch
Wind River basin
Yellowstone province*


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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).