TY  - JOUR
A1  - Thiede, Rasmus Christoph
A1  - Ehlers, Todd
T1  - Large spatial and temporal variations in Himalayan denudation
T2  - Earth & planetary science letters
N2  - In the last decade growing interest has emerged in quantifying the spatial and temporal variations in mountain building. Until recently, insufficient data have been available to attempt such a task at the scale of large orogens such as the Himalaya. The Himalaya accommodates ongoing convergence between India and Eurasia and is a focal point for studying orogen evolution and hypothesized interactions between tectonics and climate. Here we integrate 1126 published bedrock mineral cooling ages with a transient 1D Monte-Carlo thermal-kinematic erosion model to quantify the denudation histories along similar to 2700 km of the Himalaya. The model free parameter is a temporally variable denudation rate from 50 Ma to present. Thermophysical material properties and boundary conditions were tuned to individual study areas. Monte-Carlo simulations were conducted to identify the range of denudation histories that can reproduce the observed cooling ages. Results indicate large temporal and spatial variations in denudation and these are resolvable across different tectonic units of the Himalaya. More specifically, across > 1000 km of the southern Greater Himalaya denudation rates were highest (similar to 1.5-3 mm/yr) between similar to 10 and 2 Ma and lower (0.5-2.6 mm/yr) over the last 2 My. These differences are best determined in the NW-Himalaya. In contrast to this, across the similar to 2500 km length of the northern Greater Himalaya denudation rates vary over length scales of similar to 300-1700 km. Slower denudation (<1 mm/yr) occurred between 10 and 4 Ma followed by a large increase (1.2-2.6 mm/yr) in the last similar to 4 Ma. We find that only the southern Greater Himalayan Sequence clearly supports a continuous co-evolution of tectonics, climate and denudation. Results from the higher elevation northern Greater Himalaya suggest either tectonic driven variations in denudation due to a ramp-flat geometry in the main decollement and/or recent glacially enhanced denudation.
KW  - Himalaya
KW  - exhumation
KW  - low temperature chronology
KW  - thermal modeling
KW  - erosion
Y1  - 2013
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/34965
SN  - 0012-821X
VL  - 371
IS  - 2
SP  - 278
EP  - 293
PB  - Elsevier
CY  - Amsterdam
ER  -