New Al-26/Be-10 and (U-Th)/He constraints on the age of the Upland Complex, central Mississippi River Valley

Odom, William; Hofmann, Florian; Arsdale, Roy van and Granger, Darryl (2020): New Al-26/Be-10 and (U-Th)/He constraints on the age of the Upland Complex, central Mississippi River Valley. In: Geomorphology, Vol. 371, 107448

Abstract

The Upland Complex is a widespread terrace of the ancestral Mississippi River. It has played a central role in stud-ies of the Pliocene Mississippi River drainage, as well as uplift and seismicity in the central Mississippi River Valley. Previous efforts to date the Upland Complex have yielded a range of age estimates spanning the Miocene through Pleistocene. We dated gravels and Fe-oxide cements from quarries of the Upland Complex in Arkansas, Kentucky, Mississippi, and Tennessee using Al-26/Be-10 burial dating and (U-Th)/He geochronology. Our Al-26/Be-10 burial dates revealed possible Pliocene-to-Pleistocene depositional ages, while (U-Th)/He dating showed that the onset of weathering dates to at least the Pliocene. Taken together, the Al-26/Be-10 and (U-Th)/He age constraints demonstrate that the Upland Complex is at least Pliocene in age, and likely formed during a prolonged period of base level stability that preceded Pleistocene glaciations. Published by Elsevier B.V.

• Item Type: Journal article
• Faculties: Geosciences > Department of Earth and Environmental Sciences
• Subjects: 500 Science > 550 Earth sciences and geology
• ISSN: 0169-555X
• Language: English