Usage:
Duperow Formation of Jefferson Group (subsurface of MT*,ND*,SD*)
Duperow Formation (WY*)
Subunits:
(alphabetical) --all in MT: Elstow Member, Saskatoon Member, Seward Member, Wymark Member.
Geologic age:
Late Devonian*
Type section, locality, area and/or origin of name:
Type section (subsurface): depth-interval 10,400 to 10,743 [ft], Mobil Producing Company Birdbear No. 1 well, in center SE/4 NW/4 sec. 22, T. 149 N., R. 91 W., Dunn Co., ND (Sandberg and Hammond, 1958).
AAPG geologic province:
Williston basin*
Powder River basin*
Central Montana uplift*
Sweetgrass arch*
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 ([ ]).