Hoback Formation

Hoback Formation
Stratigraphic range: Paleogene
Type Formation
Underlies Pass Peak Conglomerate
Thickness 4572 m
Location
Region Wyoming
Country United States
Type section
Named for Hoback River

The Hoback Formation is a geologic formation in west-central Wyoming, located within the Hoback Basin (directly north of the Green River Basin). It formed as a result of increased sedimentation rates from the Laramide Orogeny[1] and preserves fossils dating back to the late Paleogene period, through the early Eocene.

The Hoback Formation was likely formed in a forested floodplain environment during a period of humid climate, as indicated by plentiful coal, carbonaceous shale, and fossilized plant remains. Many of the beds observed are dull in color, indicating that they formed in a reducing environment - another sign of a floodplain depositional environment, as standing water and waterlogged soil would be present for a substantial portion of the year. A prominent sandstone facies (with crossbedding, overbank deposits, and large pebbly deposits), thought to represent a large stream, is also present through much of the formation.[2]

Fossils found within the Hoback Formation include bone fragments, turtles, larger mammals, molluscs, scales, fish teeth, and a wide variety of fossilzed plant material (including fossilized wood). Signs of early Cenozoic crocodiles have also been found.[1]

See also

References

  1. 1 2 Dorr, John (January 1962). "Early Cenozoic stratigraphy and vertebrate paleontology of the Hoback Basin, Wyoming". GSA Bulletin. 63.
  2. ↑ Spearing, Darwin (1969). "Stratigraphy and sedimentation of the Paleocene-Eocene Hoback Formation, Western Wyoming" (PDF). Wyoming Geological Association Guidebook.


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