U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database

Geologic Unit: Darwin

Usage:

Darwin Sandstone Member of Amsden Formation (MT*,WY*)
Darwin Sandstone Member of Hartville Formation (WY*)
Originally misspelled Dorwin.


Geologic age:

Middle and Late Mississippian (Meramecian and Chesterian)**


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

Named from exposures on Dorwin [Darwin] Peak, Gros Ventre Range, WY (Blackwelder, 1918).
Reference section: in Tensleep Canyon on west flank, Bighorn Mountains (sta. 190), in T. 47 N., R. 88 W., Washakie Co., WY (Mallory, 1967).


AAPG geologic province:

Bighorn basin*
Denver basin*
Green River basin*
Montana folded belt*
Powder River basin*
Snake River basin*
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 ([ ]).