10Be-derived Himalayan denudation rates and sediment budgets in the Ganga basin

摘要: Abstract The Himalayas represent the archetype of mountain building due to active continental collision and are considered in many studies as locus intense interactions between climate, denudation tectonics. Estimates modern rates across entire range remain, however, relatively sparse. In this study, situ-produced cosmogenic 10 Be concentrations were measured detritic quartz order determine basin-scale for central part Himalayan range. River sand was sampled over several years main trans-Himalayan rivers, from front Ganga outlet Bangladesh. calculated river basins 0.5 2.4 mm yr −1 (average 1.3 mm yr ) vary by up a factor 3 sampling years. These strongly contrast with 0.007 mm yr rate southern tributary draining Indian craton. This work also shows that basin, no systematic evolution average is observed during floodplain transfer, implying distal samples can be used estimate integrated whole Samples Bangladesh display remarkably low variability concentration, an 1.0–1.1 mm yr . However, within floodplain, suggest recent perturbation sediment transport dynamics increase relative contribution tributaries. flux, deduced range, 610±230 Mt yr flux consistent, uncertainty, fluxes derived gauging. similarity two estimates suggests erosion have remained stable last centuries, even if large uncertainties associated each method hamper more precise assessments.