CaltechAUTHORS
  A Caltech Library Service

Postglacial denudation of western Tibetan Plateau margin outpaced by long-term exhumation

Munack, Henry and Korup, Oliver and Resentini, Alberto and Limonta, Mara and Garzanti, Eduardo and Blöthe, Jan H. and Scherler, Dirk and Wittmann, Hella and Kubik, Peter W. (2014) Postglacial denudation of western Tibetan Plateau margin outpaced by long-term exhumation. Geological Society of America Bulletin, 126 (11-12). pp. 1580-1594. ISSN 0016-7606. https://resolver.caltech.edu/CaltechAUTHORS:20141201-100001088

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20141201-100001088

Abstract

The Indus River, one of Asia’s premier rivers, drains the western Tibetan Plateau and the Nanga Parbat syntaxis. These two areas juxtapose some of the lowest and highest topographic relief and commensurate denudation rates in the Himalaya-Tibet orogen, respectively, yet the spatial pattern of denudation rates upstream of the syntaxis remains largely unclear, as does the way in which major rivers drive headward incision into the Tibetan Plateau. We report a new inventory of ^(10)Be-based basinwide denudation rates from 33 tributaries flanking the Indus River along a 320 km reach across the western Tibetan Plateau margin. We find that denudation rates of up to 110 mm k.y.^(–1) in the Ladakh and Zanskar Ranges systematically decrease eastward to 10 mm k.y.^(–1) toward the Tibetan Plateau. Independent results from bulk petrographic and heavy mineral analyses support this denudation gradient. Assuming that incision along the Indus exerts the base-level control on tributary denudation rates, our data show a systematic eastward decrease of landscape downwearing, reaching its minimum on the Tibetan Plateau. In contrast, denudation rates increase rapidly 150–200 km downstream of a distinct knickpoint that marks the Tibetan Plateau margin in the Indus River longitudinal profile. We infer that any vigorous headward incision and any accompanying erosional waves into the interior of the plateau mostly concerned reaches well below this plateau margin. Moreover, reported long-term (>10^6 yr) exhumation rates from low-temperature chronometry of 0.1–0.75 mm yr^(–1) consistently exceed our ^(10)Be-derived denudation rates. With averaging time scales of 10^3–10^4 yr for our denudation data, we report postglacial rates of downwearing in a tectonically idle landscape. To counterbalance this apparent mismatch, denudation rates must have been higher in the Quaternary during glacial-interglacial intervals.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1130/B30979.1DOIArticle
http://bulletin.geoscienceworld.org/content/126/11-12/1580PublisherArticle
http://gsabulletin.gsapubs.org/content/126/11-12/1580PublisherArticle
ORCID:
AuthorORCID
Scherler, Dirk0000-0003-3911-2803
Additional Information:© 2014 Geological Society of America. Received 19 August 2013. Revision received 15 April 2014. Accepted 16 April 2014. This work was funded by the German Research Foundation (DFG KO3937/1, 2), and the Potsdam Research Cluster for Georisk Analysis, Environmental Change and Sustainability (PROGRESS). We thank Johanna Meyer, Martin Struck, Piero Catarraso, Robert Weißbach, Judith Thäle, Franziska Scheffl er, Bettina Richter, Anja Städtke, and Antje Musiol for assisting with sample preparation. We are grateful for fi eld assistance from Tsering Lonpo, Tsering Samphel, and Tinles Nubuu. We appreciated comments by Sarah Penniston-Dorland, Craig Dietsch, and an anonymous reviewer, and thank Christian Köberl for handling the manuscript.
Funders:
Funding AgencyGrant Number
Deutsche Forschungsgemeinschaft (DFG)KO3937/1, 2
Potsdam Research Cluster for Georisk Analysis, Environmental Change and Sustainability (PROGRESS)UNSPECIFIED
Issue or Number:11-12
Record Number:CaltechAUTHORS:20141201-100001088
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20141201-100001088
Official Citation:Henry Munack, Oliver Korup, Alberto Resentini, Mara Limonta, Eduardo Garzanti, Jan H. Blöthe, Dirk Scherler, Hella Wittmann, and Peter W. Kubik Postglacial denudation of western Tibetan Plateau margin outpaced by long-term exhumation Geological Society of America Bulletin, November 2014, v. 126, no. 11-12, p. 1580-1594, first published on May 22, 2014, doi:10.1130/B30979.1
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:52208
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:01 Dec 2014 18:09
Last Modified:09 Mar 2020 13:19

Repository Staff Only: item control page