Tensleep Formation | |
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Stratigraphic range: Late Pennsylvanian-very Early Permian ~ | |
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Type | Geological formation |
Underlies | Phosphoria & Chugwater Formations |
Overlies | Sacajewea & Amsden Formations |
Thickness | up to 535 feet (160 m) |
Lithology | |
Primary | Sandstone |
Other | Limestone |
Location | |
Coordinates | 42°36′N 108°12′W / 42.6°N 108.2°W |
Approximate paleocoordinates | 4°18′N 35°12′W / 4.3°N 35.2°W |
Region | ![]() |
Country | ![]() |
Type section | |
Named for | Ten Sleep, Wyoming |
Named by | N.H. Darton[1] |
Year defined | 1904 |
The Tensleep Sandstone is a geological formation of Pennsylvanian to very early Permian age in Wyoming.[2]
The formation is composed of fine- to medium-grained sandstone, light gray and yellowish gray; generally slightly to moderately calcareous; some dolomite and sandy dolomite beds; mostly thick to massive sets of low-angle, wedge-planar crossbeds of dunes. Forms cliffs 61-91m (200-300 feet) thick.[3]
In 1932 Edward Branson and Maurice Mehl reported the discovery of a fossil trackway in the formation.[4] A new ichnospecies, Steganoposaurus belli, was erected for these footprints.[4] The tracks were probably made by a web-footed animal slightly less than three feet long.[4] This creature was originally presumed to be an amphibian, but the toe prints it left behind were pointed like a reptile's rather than round like an amphibians. The actual trackmaker may have been similar to the genus Hylonomus.[5] The ichnogenus Tridentichnus are similar footprints preserved in the Supai Formation of Arizona.[6]