Hoback Formation
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.
| 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 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 fossilized plant material (including fossilized wood). Signs of early Cenozoic crocodiles have also been found.[1]
References
- Dorr, John (January 1962). "Early Cenozoic stratigraphy and vertebrate paleontology of the Hoback Basin, Wyoming". GSA Bulletin. 63. doi:10.1130/0016-7606(1952)63[59:ecsavp]2.0.co;2.
- Spearing, Darwin (1969). "Stratigraphy and sedimentation of the Paleocene-Eocene Hoback Formation, Western Wyoming" (PDF). Wyoming Geological Association Guidebook.
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 31 July 2014. Retrieved 8 July 2014.