Cotter Formation | |
---|---|
Stratigraphic range: Ordovician | |
Type | Formation |
Underlies | Powell Formation |
Overlies | Jefferson City Formation |
Lithology | |
Primary | Dolomite |
Other | Chert, sandstone, shale |
Location | |
Region | Arkansas, Missouri, Oklahoma, Virginia |
Country | United States |
Type section | |
Named for | Cotter, Baxter County, Arkansas |
Named by | Edward Oscar Ulrich[1] |
The Cotter Formation is a geologic formation in Arkansas,[2] Missouri,[3] Oklahoma[4] and in Virginia. It preserves fossils dating back to the Ordovician period.