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Topo

Rock Formations

Measure

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Topo

Ecoregions

Public Lands

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Tensleep Sandstone and Amsden Formation (WYPM;0)

Geologic Formation in WY, MT

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Lithology

Dolostone

Shale

Sandstone

Other (1,030 mi²)

Geologic Age

Mississippian – Permian (359.3 Ma – 252.23 Ma ago)

Geologic Unit Label

PM

Tensleep Sandstone (North Wyoming) - White to gray sandstone containing thin limestone and dolomite beds. Permian fossils have been found in the topmost beds of the Tensleep at some localities in Washakie Range, Owl Creek Mountains, and southern Bighorn Mountains. Amsden Formation (North Wyoming) - Red and green shale and dolomite; at base is brown sandstone. Tensleep Sandstone (Sorth Wyoming) - White to gray sandstone containing thin limestone and dolomite beds. Amsden Formation (South Wyoming) - Red and green shale and dolomite; at base is persistent red to brown sandstone.

— USGS

Taxonomy

Classified As

Geologic Formation