Entrada Sandstone | |
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Stratigraphic range: | |
Type | Geological formation |
Sub-units | Cannonville Member, Cow Springs Member, Dewey Bridge Member, Escalante Member, Henrieville Member, EExeter Member, Gunsight Butte Member, Iyanbito Member, Moab Member, Red Mesa Member, Slick Rock Member |
Underlies | Curtis Formation Todilto Formation |
Overlies | Carmel Formation |
Lithology | |
Primary | fluvial mudstone, siltstone, and eolian sandstone |
Location | |
Coordinates | 39°15′40″N 110°32′35″W / 39.261°N 110.543°W |
Region | Colorado Plateau |
Country | United States |
Type section | |
Named for | Entrada Point, northern San Rafael Swell |
Named by | James Gilluly and J.B. Reeside, Jr. (1928) |
The Entrada Sandstone is a formation in the San Rafael Group found in the U.S. states of Wyoming, Colorado, northwest New Mexico, northeast Arizona, and southeast Utah. Part of the Colorado Plateau, this formation was deposited during the Jurassic Period sometime between 180 and 140 million years ago in various environments, including tidal mudflats, beaches, and sand dunes.[1] The Middle Jurassic San Rafael Group was dominantly deposited as ergs (sand seas) in a desert environment around the shallow Sundance Sea.[2][3][self-published source?]