Coupling of rock uplift and river incision in the Namche Barwa-Gyala Peri massif, Tibet

Noah J. Finnegan, Bernard Hallet, David R. Montgomery, Peter K. Zeitler, John O. Stone, Alison M. Anders, Liu Yuping

Research output: Contribution to journalArticle

Abstract

Geodynamic modeling demonstrates the strong potential for erosion to influence the pattern and style of deformation in active mountain belts, but field studies yield conflicting views on the importance of erosion in influencing orogenesis. Here we compare patterns in river power, inferred excess fluvial-transport capacity, topographic relief, precipitation, and mineral-cooling ages to assess the coupling between surface erosion and rock uplift within the vicinity of the Namche Barwa-Gyala Peri massif, an active antiformal structure within the eastern Himalayan syntaxis. Our rich and dense data set reveals a tight spatial correspondence of fluvial incision potential, high relief, and young cooling ages. The spatial coincidence is most easily explained by a sustained balance between rock uplift and denudation driven by river incision over at least the last ∼1 m.y. The Yarlung Tsangpo-Brahmaputra River is the largest and most powerful river in the Mmalaya, and two lines of evidence point to its active role in the dynamic interaction of local erosion, rock uplift, thermal weakening of the lithosphere, and deformation: (1) Whereas along the rest of the Himalayan front, high relief and high rock uplift rates are essentially continuous, the high relief and rapid exhumation in the syntaxis is restricted to a "bull's-eye" pattern exactly where the largest river in the Himalaya, the Yarlung Tsangpo-Brahmaputra, has the most energy per unit area avaflable to erode its channel and transport sediment. (2) The location of rapid incision on the Yarlung Tsangpo-Brahmaputra has been pinned for at least 1 m.y., and without compensatory uplift of the Namche Barwa-Gyala Peri massif during this time the river would have eroded headward rapidly, incising deeply into Tibet.

Original languageEnglish (US)
Pages (from-to)142-155
Number of pages14
JournalBulletin of the Geological Society of America
Volume120
Issue number1-2
DOIs
StatePublished - Jan 1 2008

    Fingerprint

Keywords

  • Climate
  • Eastern Himalayan syntaxis
  • Namche Barwa
  • River incision
  • Rock uplift
  • Tectonics and landscape evolution

ASJC Scopus subject areas

  • Geology

Cite this

Finnegan, N. J., Hallet, B., Montgomery, D. R., Zeitler, P. K., Stone, J. O., Anders, A. M., & Yuping, L. (2008). Coupling of rock uplift and river incision in the Namche Barwa-Gyala Peri massif, Tibet. Bulletin of the Geological Society of America, 120(1-2), 142-155. https://doi.org/10.1130/B26224.1