4.8 Article

Erosion in southern Tibet shut down at ∼10 Ma due to enhanced rock uplift within the Himalaya

Publisher

NATL ACAD SCIENCES
DOI: 10.1073/pnas.1515652112

Keywords

Tibet-Himalaya; thermochronometry; landscape evolution

Funding

  1. National Science Foundation (NSF) Continental Dynamics program [EAR-1111853]
  2. NSF Graduate Research Fellowship
  3. University of California-Berkeley Larsen grant
  4. Ann and Gordon Getty Foundation
  5. NSF Instrumentation & Facilities program [EAR-1339051]
  6. Division Of Earth Sciences
  7. Directorate For Geosciences [1111515, 1111853] Funding Source: National Science Foundation

Ask authors/readers for more resources

Exhumation of the southern Tibetan plateau margin reflects interplay between surface and lithospheric dynamics within the Himalaya-Tibet orogen. We report thermochronometric data from a 1.2-km elevation transect within granitoids of the eastern Lhasa terrane, southern Tibet, which indicate rapid exhumation exceeding 1 km/Ma from 17-16 to 12-11 Ma followed by very slow exhumation to the present. We hypothesize that these changes in exhumation occurred in response to changes in the loci and rate of rock uplift and the resulting southward shift of the main topographic and drainage divides from within the Lhasa terrane to their current positions within the Himalaya. At similar to 17 Ma, steep erosive drainage networks would have flowed across the Himalaya and greater amounts of moisture would have advected into the Lhasa terrane to drive large-scale erosional exhumation. As convergence thickened and widened the Himalaya, the orographic barrier to precipitation in southern Tibet terrane would have strengthened. Previously documented midcrustal duplexing around 10 Ma generated a zone of high rock uplift within the Himalaya. We use numerical simulations as a conceptual tool to highlight how a zone of high rock uplift could have defeated transverse drainage networks, resulting in substantial drainage reorganization. When combined with a strengthening orographic barrier to precipitation, this drainage reorganization would have driven the sharp reduction in exhumation rate we observe in southern Tibet.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.8
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available