| Gypsum Spring Formation | |
| Type: | Geological formation |
| Prilithology: | Gypsum |
| Otherlithology: | Shale, dolomite, limestone |
| Namedfor: | Gypsum Spring, Wyoming |
| Namedby: | J.D. Love, 1939 |
| Region: | Williston Basin |
| Country: |  United States |
| Thickness: | up to 76m (249feet) |
| Period: | Middle Jurassic |
The Gypsum Spring Formation is a stratigraphical unit of Middle Jurassic age in the Williston Basin.
It takes the name from Gypsum Spring in Wyoming, and was first described in outcrop in Freemont County by J.D. Love in 1939.[1]
The Gypsum Spring Formation is composed of massive white gypsum in the lower part, and alternating gypsum, red shale, dolomite and limestone.[2]
The Gypsum Spring Formation reaches a maximum thickness of 76m (249feet) in central Wyoming.[2] It occurs from the Black Hills in South Dakota through Wyoming and into southern Saskatchewan.
It is equivalent to the upper part of the Watrous Formation and the lower part of the Gravelbourg Formation in Saskatchewan.