Jackson Group
| Jackson Group | |
|---|---|
| Stratigraphic range: Paleogene | |
| Type | Group |
| Sub-units | White Bluff Formation, Redfield Formation |
| Overlies | Claiborne Group |
| Location | |
| Region | Arkansas, North Carolina |
| Country | United States |
| Type section | |
| Named by | Timothy Abbott Conrad[1] |
The Jackson Group is a geologic group in Arkansas, North Carolina and Tennessee. It preserves fossils dating back to the Paleogene to Neogene period. The area is where the type specimen of Basilosaurus, an ancient whale first thought to be a reptile, was found. Exposed only in bluffs along Mississippi River with thickness at least 60 feet. Primary rock type is sand. Secondary rock type is clay or mud. Other rock types include slit and lignite. "Light gray to buff, medium- to very fine-grained silty sand, interbedded with light gray clayey silt."[2] From the Tertiary geological age.[2]
Jackson Formation siltstones are exposed in western Tennessee in the Mississippi River bluffs.[3]
See also
References
- ^ Conrad, T.A. (1847). "Observations on the Eocene formation, and descriptions of one hundred and five new fossils of that period, from the vicinity of Vicksburg, Mississippi, with an Appendix". Proceedings of the Academy of Natural Sciences of Philadelphia. 3: 280–282.
- ^ a b Van Arsdale, Roy; Pryne, Daniel; Woolery, Edward (2013-10-24). "Northwestern Extension of the Reelfoot North Fault Near New Madrid, Missouri". Seismological Research Letters. 84: 1118, 1114–1123. doi:10.1785/0220130067.
- ^ Van Arsdale, Roy. "Final Report for SG-4 Characterization of Active Faults in the New Madrid Seismic Zone" (PDF). MAE Center. p. 18. Retrieved 12 June 2018.