Gypsum Spring Formation

The Gypsum Spring Formation is a stratigraphical unit of Middle Jurassic age in the Williston Basin.

Gypsum Spring Formation
Stratigraphic range: Middle Jurassic
Gypsum Spring Formation (in grey on top of red colored Spearfish Formation), near Devils Tower National Monument (Wyoming)
TypeGeological formation
UnderliesSundance Formation
Thicknessup to 76 metres (250 ft)[1]
Lithology
PrimaryGypsum
OtherShale, dolomite, limestone
Location
RegionWilliston Basin
Country United States
Type section
Named forGypsum Spring, Wyoming
Named byJ.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

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The Gypsum Spring Formation is composed of massive white gypsum in the lower part, and alternating gypsum, red shale, dolomite and limestone. [1]

Distribution

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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

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It is equivalent to the upper part of the Watrous Formation and the lower part of the Gravelbourg Formation in Saskatchewan.

References

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  1. ^ a b c Lexicon of Canadian Geologic Units. "Gypsum Springs Formation". Retrieved 2010-02-01.
  2. ^ Love, J.D., 1939. Geology along the southern margin of the Absaroka Range. Wyoming. Geological Society of America, Spec. Paper 20, p. 45.