Prairie Formation of Elk Point Group (MT*,ND*)
Middle Devonian*
Type section (subsurface): depth-interval 4,352 to 5,000 ft, Imperial Davidson No. 1 well, LSD 16-8-27-1 West of 3rd Meridian (W3M), Saskatchewan, Canada (Baillie, 1953).
Typical section [amended?] (subsurface): depth-interval 3,259 to 3,894 ft, White Rose et al Drake 4-29-32-22 well, LSD 4-29-32-22 West of 2nd Meridian (W2M), Sasketchewan, Canada (Holter, 1969; CSPG Western Canada Lexicon).
Williston basin*
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 ([ ]).