Asymmetrical erosion and morphological development of the central Ladakh Range, northern India

Variations in erosion were quantified across the topographically and morphometrically asymmetrical central Ladakh Range in NW India to elucidate erosion and sediment transfer processes across space and time and to gain insight into how mountains erode and evolve. Morphometric analysis and ¹⁰Be cosmogenic nuclide analysis of 14 fluvial sediment samples from active channels in six catchments conducted across the mountain range constrains 100ka timescale erosion rates for catchments on the northern side of the mountain range and are between 56±12 and 74±11m/Ma, while catchments on the southern side of the mountain range to between 20±3 and 39±8m/Ma for the last ~300ka. Maximum elevation from swath analysis across the range shows a strong correlation with the ELAs of 382 contemporary glaciers. The higher erosion rate to the north likely relates to tectonic tilting of the central Ladakh Range and to active rock uplift on the northern side of the range along the Karakoram Fault. Morphometric analysis shows that the maximum and average elevations increase at nearly the same rate on a catchment-scale across the central Ladakh Range, with higher elevation on the northern side. This suggests that greater erosion on the northern side of the range is not keeping pace with rock uplift. Moreover, long-term denudational unloading does not play a significant role in the tectonic tilting of the central Ladakh Range.