New ²⁶Al/¹⁰Be and (U-Th)/He constraints on the age of the Upland Complex, central Mississippi River Valley
Abstract
The Upland Complex is a widespread terrace of the ancestral Mississippi River. It has played a central role in studies 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 ²⁶Al/¹⁰Be burial dating and (U-Th)/He geochronology. Our ²⁶Al/¹⁰Be 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 ²⁶Al/¹⁰Be 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.
Additional Information
© 2020 Published by Elsevier B.V. Received 10 June 2020, Revised 24 September 2020, Accepted 25 September 2020, Available online 3 October 2020. We thank Greg Balco for his work to date the Arlington quarry. We wish to thank a number of people who allowed us to sample in their quarries: Jeff Drum (Drum Sand and Gravel, Inc.), Ken McCarley (Kuhn quarry owned by Hammett Gravel Company, Inc.), David Gavin (Mid-South Construction and Old Hickory Clay Company), Dale Gulledge (Tri-County Sand and Gravel quarry). We are also grateful for Ken Miller for providing us with the sea level curve data. Thoughtful suggestions from Atsunori Nakamura, Lewis Owen, and an anonymous reviewer helped us improve the manuscript. This project was partially supported by the National Science Foundation (Grant #1700821) and a PRIME Lab seed grant. Data availability: A complete dataset of (U-Th)/He ages, goethite compositions, and related data are included in the supplementary spreadsheet. This document also includes ²⁶Al/¹⁰Be data, burial ages, and non-blank-corrected AMS data for ²⁶Al/²⁷Al and ¹⁰Be/⁹Be measurements. MATLAB code for likelihood function calculations is included in supplementary documentation. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.Additional details
- Alternative title
- New 26Al/10Be and (U-Th)/He constraints on the age of the Upland Complex, central Mississippi River Valley
- Eprint ID
- 107066
- Resolver ID
- CaltechAUTHORS:20201214-120018947
- EAR-1700821
- NSF
- PRIME Lab
- Created
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2020-12-14Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field