Cosmogenic and Geological Evidence for the Occurrence of a Ma-Long Feedback between Uplift and Denudation, Chur Region, Swiss Alps

da Silva Guimarães, Ewerton; Delunel, Romain; Schlunegger, Fritz; Akçar, Naki; Stutenbecker, Laura; Christl, Marcus (2021). Cosmogenic and Geological Evidence for the Occurrence of a Ma-Long Feedback between Uplift and Denudation, Chur Region, Swiss Alps. Geosciences, 11(8), p. 339. MDPI 10.3390/geosciences11080339

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We used concentrations of in situ cosmogenic 10Be from riverine sediment to quantify the basin‐averaged denudation rates and sediment fluxes in the Plessur Basin, Eastern Swiss Alps, which is a tributary stream to the Alpine Rhine, one of the largest streams in Europe. We comple‐ ment the cosmogenic dataset with the results of morphometric analyses, geomorphic mapping, and sediment fingerprinting techniques. The results reveal that the Plessur Basin is still adjusting to the landscape perturbation caused by the glacial carving during the Last Glacial Maximum c. 20,000 years ago. This adjustment has been most efficient in the downstream part where the bed‐ rock comprises high erodibility North Penninic flysch and Bündnerschist, whereas glacial land‐ forms are still prominently preserved in the upstream region, comprising low erodibility South Penninic and Austroalpine bedrock. This geomorphic observation is supported by the 10Be based denudation rate and sediment provenance analysis, which indicate a much faster sediment pro‐ duction in the flysch and schist lithologies. Interestingly, the reach of fast denudation has experi‐ enced the highest exhumation and rock uplift rates. This suggests that lithologic and glacial condi‐ tioning have substantially contributed to the local uplift and denudation as some of the driving forces of a positive feedback system.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences

UniBE Contributor:

Da Silva Guimarães, Ewerton; Delunel, Romain; Schlunegger, Fritz and Akçar, Naki

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

2076-3263

Publisher:

MDPI

Language:

English

Submitter:

Fritz Schlunegger

Date Deposited:

13 Aug 2021 13:29

Last Modified:

13 Aug 2021 13:29

Publisher DOI:

10.3390/geosciences11080339

BORIS DOI:

10.48350/158168

URI:

https://boris.unibe.ch/id/eprint/158168

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