Denudation of the Himalayan Orogen
Abstract
Quantifying spatial and temporal variations in denudation rates across orogenic belts are not only essential for measuring potential linkages between tectonics and climate, but also for understanding it's impact on regional and global evolution. The 2500 km long Himalayan Arc marked by spatial variations in deformation and climate, both of which would suggest non uniform exhumation histories of rocks exposed at the surface today, offers an ideal location to study this. It has been proposed that erosional exhumation may be highest in the orogen syntaxes forming the orogen termination with the Namche Barwa in the east and Nanga Parbat in the west, compared to the arc. Finally, growth of the Himalaya and the Tibetan plateau are significant events that modified global and regional climate by forming the Asian Monsoon, and furthermore, possibly triggered worldwide decrease of atmospheric CO2- concentration. Here we present ~850 compiled Apatite, Zircon Fission Track and 40Ar/39Ar-white mica and previous published mineral cooling ages obtained from in-situ samples across the Himalayan arc. We apply a 1D thermo-kinematic and erosional model to reconstruct and quantify denudation rates along the arc. Our results suggest that over the past ~23 Myr (1) the mountain front has tectonically reorganized itself and shifted location of focused denudation twice (17-15 and 3-2 Ma), (2) the denudation rates in the syntaxes have been similar to twice as high compared to the Himalayan front, and (3) in general our results are in great agreement with results from provenance of the foreland basin sediments.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.T53A1900T
- Keywords:
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- 1815 Erosion;
- 8175 Tectonics and landscape evolution;
- 8177 Tectonics and climatic interactions