Episodic overbank deposition as a dominant mechanism of floodplain and delta-plain aggradation



Shen, Zhixiong, Toernqvist, Torbjoern E, Mauz, Barbara, Chamberlain, Elizabeth L, Nijhuis, Austin G and Sandoval, Laure
(2015) Episodic overbank deposition as a dominant mechanism of floodplain and delta-plain aggradation. GEOLOGY, 43 (10). pp. 875-878.

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Abstract

The common view that frequent overbank flooding leads to gradual aggradation of alluvial strata on floodplains and delta plains has been challenged by a variety of studies that suggest that overbank aggradation occurs in a strongly episodic fashion. However, this remains a largely untested hypothesis due to the difficulty in establishing age models with sufficiently high resolution. Here we use 39 optically stimulated luminescence (OSL) ages from proximal overbank deposits in the Mississippi Delta to demonstrate for the first time that alluvial aggradation over centennial to millennial time scales is predominantly episodic, with aggradation rates of 1-4 cm/yr that can persist for centuries. OSL ages from three separate study areas produce age clusters that are distinctly different yet complement each other. These findings suggest that a substantial portion of the continental stratigraphic record consists of patchworks of relatively discrete, centennial- to millennial-scale sediment bodies assembled by autogenic processes.

Item Type: Article
Uncontrolled Keywords: 37 Earth Sciences, 3709 Physical Geography and Environmental Geoscience, 3705 Geology
Depositing User: Symplectic Admin
Date Deposited: 25 Feb 2016 10:27
Last Modified: 21 Jun 2024 01:15
DOI: 10.1130/G36847.1
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/2052879