Be-10 erosion rates controlled by transient response to normal faulting through incision and landsliding
- Quantifying erosion rates, and how they compare to rock uplift rates, is fundamental for understanding landscape response to tectonics and associated sediment fluxes from upland areas. The erosional response to uplift is well-represented by river incision and the associated landslide activity. However, characterising the relationship between these processes remains a major challenge in tectonically active areas, in some cases because landslides can preclude obtaining reliable erosion rates from cosmogenic radionuclide (CRN) concentrations. Here, we quantify the control of tectonics and its coupled geomorphic response on the erosion rates of catchments in southern Italy that are experiencing a transient response to normal faulting. We analyse in-situ Be-10 concentrations for detrital sediment samples, collected along the strike of faults with excellent tectonic constraints and landslide inventories. We demonstrate that Be-10-derived erosion rates are controlled by fault throw rates and the extent of transient incision and associatedQuantifying erosion rates, and how they compare to rock uplift rates, is fundamental for understanding landscape response to tectonics and associated sediment fluxes from upland areas. The erosional response to uplift is well-represented by river incision and the associated landslide activity. However, characterising the relationship between these processes remains a major challenge in tectonically active areas, in some cases because landslides can preclude obtaining reliable erosion rates from cosmogenic radionuclide (CRN) concentrations. Here, we quantify the control of tectonics and its coupled geomorphic response on the erosion rates of catchments in southern Italy that are experiencing a transient response to normal faulting. We analyse in-situ Be-10 concentrations for detrital sediment samples, collected along the strike of faults with excellent tectonic constraints and landslide inventories. We demonstrate that Be-10-derived erosion rates are controlled by fault throw rates and the extent of transient incision and associated landsliding in the catchments. We show that the low-relief sub-catchments above knickpoints erode at uniform background rates of similar to 0.10 mm/yr, while downstream of knickpoints, erosion removes similar to 50% of the rock uplifted by the faults, at rates of 0.10-0.64 mm/yr. Despite widespread landsliding, CRN samples provide relatively consistent and accurate erosion rates, most likely because landslides are frequent, small, and shallow, and represent the integrated record of landsliding over several seismic cycles. Consequently, we combine these validated Be-10 erosion rates and data from a geomorphological landslide inventory in a published numerical model, to gain further insight into the long-term landslide rates and sediment mixing, highlighting the potential of CRN data to study landslide dynamics. (C) 2018 Elsevier B.V. All rights reserved.…
Author details: | Duna C. Roda-BoludaORCiD, Alexander C. WhittakerORCiD, Delia M. Gheorghiu, Angel RodesORCiD, Mitch D'Arcy |
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DOI: | https://doi.org/10.1016/j.epsl.2018.11.032 |
ISSN: | 0012-821X |
ISSN: | 1385-013X |
Title of parent work (English): | Earth & planetary science letters |
Publisher: | Elsevier |
Place of publishing: | Amsterdam |
Publication type: | Article |
Language: | English |
Date of first publication: | 2019/12/13 |
Publication year: | 2019 |
Release date: | 2021/04/16 |
Tag: | cosmogenic nuclides; erosion rates; incision; landslides; normal faults; transient response |
Volume: | 507 |
Number of pages: | 14 |
First page: | 140 |
Last Page: | 153 |
Funding institution: | Janet Watson bursary scheme at the Department of Earth Science and Engineering of Imperial College London; Geological Society of London Annie Greenly Fund; British Society for Geomorphology Postgraduate Research Grant; British Sedimentological Research Group Gill Harwood Fund; NERC CIAF Grant [9148/0414] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Peer review: | Referiert |