- Usage in publication:
-
- Big Cottonwood formation
- Modifications:
-
- Original reference
- Dominant lithology:
-
- Sandstone
- Conglomerate
- Clay
- Limestone
- Lignite
- AAPG geologic province:
-
- Sioux uplift
Summary:
Pg. 221-242. Big Cottonwood formation. Shales, sandstones, and conglomerates, red, green, white, yellow, blue, and brown. Outcrops on Big Cottonwood River and in neighboring parts of Minnesota Valley, southwestern Minnesota. All strata are fresh-water deposits and are referable to Dakota formation, although they possibly are contemporaneous with marine Colorado formation or Niobrara. Represents a river delta or filled valley of a stream which originally descended from east to west. Age is Late Cretaceous.
Source: US geologic names lexicon (USGS Bull. 896, p. 182).
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 ([ ]).