Million-year lag times in a post-orogenic sediment conveyor
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Date
2020-06-19
Journal Title
Journal ISSN
Volume Title
Publisher
American Association for the Advancement of Science
Abstract
Understanding how sediment transport and storage will delay, attenuate, and even erase the erosional signal of tectonic and climatic forcings has bearing on our ability to read and interpret the geologic record effectively. Here, we estimate sediment transit times in Australia’s largest river system, the Murray-Darling basin, by measuring downstream changes in cosmogenic 26Al/10Be/14C ratios in modern river sediment. Results show that the sediments have experienced multiple episodes of burial and reexposure, with cumulative lag times exceeding 1 Ma in the downstream reaches of the Murray and Darling rivers. Combined with low sediment supply rates and old sediment blanketing the landscape, we posit that sediment recycling in the Murray-Darling is an important and ongoing process that will substantially delay and alter signals of external environmental forcing transmitted from the sediment’s hinterland. Copyright © 2020 The Authors
Description
Keywords
Sediments, Geologic deposits, Tectonics, Erosion, Australia, Rivers
Citation
Fülöp, R.-H., Codilean, A. T., Wilcken, K. M., Cohen, T. J., Fink, D., Smith, A. M.,Yang, B., Levchenko, V. A., Wacker, L., Marx, S. K., Stomsoe, N., Fukioka, T., & Dunai, T. J. (2020). Million-year lag times in a post-orogenic sediment conveyor. Science Advances, 6(25), eaaz8845. doi:10.1126/sciadv.aaz8845 %J Science Advances