River Bend Formation

River Bend Formation
Stratigraphic range: Oligocene
Type	Formation
Lithology
Primary	limestone
Location
Region	North Carolina
Country	United States
Type section
Named for	River Bend Estates along the Trent River

The River Bend Formation is a limestone geologic formation in North Carolina. It preserves fossils dating back to the Paleogene period.

Description

The River Bend formation is a limestone formation characterized by mollusc molds, barnacle hashes, bivalves, and sandy limestone layers.^[1] Fossils indicate that the formation was deposited during the middle to late Oligocene.

History

Originally, the River Bend formation was part of a limestone unit called the Trent Marl. Further research split off the Miocene Belgrade Formation from the Trent Marl and considered the River Bend formation as part of the Castle Hayne Limestone.^[1] The River Bend formation was then identified as an Oligocene limestone and broken out from the Castle Hayne Limestone. The Trent Marl nomenclature is no longer used.

References

^ ^a ^b Ward, Lauck W.; Lawrence, David R.; Blackwelder, Blake W. (1979). "Stratigraphic revision of the middle Eocene, Oligocene, and lower Miocene; Atlantic Coastal Plain of North Carolina" (PDF). U.S. Geological Survey Bulletin. 1457-F: 3–10. Retrieved 26 June 2018.