Usage:
Amaranth Formation (subsurface of ND,SD?,WY?)
Geologic age:
Early to Middle Jurassic
Type section, locality, area and/or origin of name: (See Canadian Lexicon)
Originally used by Kirk (1930) for the gypsum-bearing beds mined at town of Amaranth, [about 5 mi west of Lake Manitoba], southwestern Manitoba, Canada.
Type sections (subsurface): (1) depth-interval 1,180 to 1,400 feet (359.7 to 426.7 m), Commonwealth Manitou No. 2 well, in 8-26-2-9 WPM, southern Manitoba; and (2) depth-interval 750 to 990 feet (228.6 to 301.7 m), Neepawa Salt Company No. 2 well, in 9-33-14-15 WPM (Wickenden, 1945).
Suggested reference section (subsurface): depth-interval 704.5 to 893 ft (214.7 to 272.2 m), Tudale Neepawa well, in 5-29-14-14 WPM (CSPG Western Canada Lexicon).
AAPG geologic province:
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 ([ ]).