Gypsum Spring Formation
Stratigraphical unit in the United States
From Wikipedia, the free encyclopedia
The Gypsum Spring Formation is a stratigraphical unit of Middle Jurassic age in the Williston Basin.
| Gypsum Spring Formation | |
|---|---|
| Stratigraphic range: | |
Gypsum Spring Formation (in grey on top of red colored Spearfish Formation), near Devils Tower National Monument (Wyoming) | |
| Type | Geological formation |
| Underlies | Sundance Formation |
| Thickness | up to 76 metres (250 ft)[1] |
| Lithology | |
| Primary | Gypsum |
| Other | Shale, dolomite, limestone |
| Location | |
| Region | Williston Basin |
| Country | Canada, United States |
| Type section | |
| Named for | Gypsum Spring, Wyoming |
| Named by | J.D. Love, 1939 |
It takes the name from Gypsum Spring in Wyoming, and was first described in outcrop in Freemont County by J.D. Love in 1939.[2]
Lithology
Distribution
The Gypsum Spring Formation reaches a maximum thickness of 76 metres (250 ft) in central Wyoming.[1] It occurs from the Black Hills in South Dakota through Wyoming and into southern Saskatchewan.
Relationship to other units
It is equivalent to the upper part of the Watrous Formation and the lower part of the Gravelbourg Formation in Saskatchewan.