Erosion and exhumation in the Himalaya from cosmogenic isotope inventories of river sediments
- 作者：Vance ; Derek ; Bickle ; Mike ; Ivy-Ochs ; Susan ; Kubik ; Peter W.
- 关键词：erosion ; cosmogenic isotopes ; Himalayas ; climate ; tectonics ; mineral cooling ages
- 刊名：Earth and Planetary Science Letters
- 出版年：2003
- 期刊代码：18_0012821x
- 类别：ph
- 出版时间：February 15, 2003
- 卷：206
- 期：3-4
- 页码：273-288
- 文件大小：2.58 M
摘要
The outward erosional flux is a key factor in the tectonic evolution of mountain belts and there is much debate about the feedbacks between tectonics, erosion and climate. Here we use cosmogenic nuclides (10Be and 26Al) analysed in quartz from river sediments from the Upper Ganges catchment to make the first direct measurements of large-scale erosion rates in a rapidly uplifting mountain belt. The erosion rates are highest in the High Himalaya at 2.7±0.3 mm/yr (1σ errors), fall to 1.2±0.1 mm/yr on the southern edge of the Tibetan Plateau and are 0.8±0.3 to <0.6 mm/yr in the foothills to the south of the high mountains. These relative estimates are corroborated by the Nd isotopic mass balance of the river sediment. Analysis of sediment from an abandoned terrace suggests that similar erosion rates have been maintained for at least the last few thousand years. The data presented here, along with data recently published for European river catchments, demonstrate that a log–linear relationship between relief and erosion rate holds over three orders of magnitude variation in erosion rate and between very different climatic and tectonic regimes.