Geological Society of America

347 Tectonics/Tectonophysics (Posters)

Wednesday, 28 September 2016
9:00 AM - 6:30 PM
Exhibit Hall E/F

BIRTH OF THE MEKONG RIVER REVEALS TOP-DOWN FORCING FOR FLUVIAL INCISION

Paper number: 347-17
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Junsheng Nie Presenting Author
University of Rochester, Rochester, NY
Junsheng Nie Presenting Author
Lanzhou University, Lanzhou
Weitao Wang
Rochester, NY
Weitao Wang
University of Rochester, Rochester, NY
Kerry Gallagher
Rennes
Carmala Garzione
University of Rochester, Rochester, NY
Gregory Hoke
Syracuse University, Syracuse, NY
Daniel F. Stockli
The University of Texas at Austin, Austin, TX
Thomas Stevens
Uppsala University, Villavägen

Abstract

The complex nature of the coupling between atmospheric, surficial, and deeper Earth processes in the development of orogens and shaping Earth’s landscape is one of the most fundamental challenges in Earth sciences. Deeply incised gorges in upland regions have the potential to reveal the nature of this coupling. Based on low-temperature thermochronology, we show that a phase of rapid >700 m downward incision in the lower reaches of the Mekong River draining the Southeastern Tibetan Plateau occurred during the middle Miocene. Paleoaltimetry data demonstrate the current elevation of the southeastern Tibetan Plateau was reached by the late Eocene, while the middle Miocene is characterized by extreme warming and intensified East Asian summer monsoon. In the absence of any obvious tectonic contribution, this provides the first unambiguous evidence for warm climatic control on km-scale fluvial incision in the Tibetan Plateau and demonstrates the importance of the monsoon in shaping Earth’s surface.

Geological Society of America Abstracts with Programs. Vol. 48, No. 7

doi: 10.1130/abs/2016AM-285246

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