Climate variability has been setting the rhythm of the Earth's history, but how does the landscape, in particular rivers, adapt to these changes? One possible approach to tackle this question is to investigate how sedimentary deposits have recorded changes in fluvial dynamics. As a proxy forthis dynamics, we use the sediment residence time, i.e. the time spent by sediments in a catchment before export (storage in soils + fluvial transport). Recently, it has been proposed that uranium-series isotopes can be used to quantify past variations in sediment residence time. In this study, this approach is applied to alluvial deposits from the upper Ganges River, the Yamuna River and the Dun valley in the foothills of the Himalayas. The age of these deposits has been previously constrained by optically-stimulated luminesence dating and range from 0 to 40 ka. Preliminary work using lithium isotopes has shown a strong link between monsoon activity and weathering intensity. Results from this study will investigate how hillslope erosion and fluvial transport may have responded to past climatic change.
|Number of pages||1|
|Publication status||Published - 2012|
|Event||International Geological Congress (34th : 2012) - Brisbane, Australia|
Duration: 5 Aug 2012 → 10 Aug 2012
|Conference||International Geological Congress (34th : 2012)|
|Period||5/08/12 → 10/08/12|
Dosseto, A., Hesse, P. P., Fink, D., & Srivastava, P. (2012). Past changes in sediment dynamics in the Himalayas inferred from uranium-series isotopes. 724. Abstract from International Geological Congress (34th : 2012), Brisbane, Australia.