Holocene erosion of the Lesser Himalaya triggered by intensified summer monsoon
Holocene erosion of the Lesser Himalaya triggered by intensified summer monsoon
复制标题
DOI：
10.1130/g24315a.1
复制
发表时间：
2008-01-01
期刊：
影响因子：
5.8
通讯作者：
Lueckge, Andreas
中科院分区：
文献类型：
--
作者：
Clift, Peter D.;Giosan, Liviu;Lueckge, Andreas
气候是决定大陆侵蚀速率的主要控制因素之一。在这里，我们介绍了印度河三角洲全新世沉积物的来源分析结果，以评估千年时间尺度上对侵蚀的气候控制。块状沉积物的Nd同位素分析表明，在晚更新世和全新世早期(14-20、11-12和8-9ka)，喀喇昆仑的侵蚀发生了一些变化，而喜马拉雅的沉积通量更大。白云母的放射性Ar-Ar定年和锆石砂粒的U-Pb定年表明，随着全球气候变暖和14ka以后夏季风的加强，小喜马拉雅山脉的侵蚀相对比大喜马拉雅山脉更强烈。季风雨似乎是控制喜马拉雅西部侵蚀的主要力量，至少在千年时间尺度上是这样。由于大陆架上的沉积物缓冲作用，这种变化在三角洲的沉积物中没有明显的滞后，但在阿拉伯海深处却没有。
Climate is one of the principal controls setting rates of continental erosion. Here we present the results of a provenance analysis of Holocene sediments from the Indus delta in order to assess climatic controls on erosion over millennial time scales. Bulk sediment Nd isotope analysis reveals a number of changes during the late Pleistocene and early Holocene (at 14-20,11-12 and 8-9 ka) away from erosion of the Karakoram and toward more sediment flux from the Himalaya. Radiometric Ar-Ar dating of muscovite and U-Pb dating of zircon sand grains indicate that the Lesser Himalaya eroded relatively more strongly than the Greater Himalaya as global climate warmed and the summer monsoon intensified after 14 ka. Monsoon rains appear to be the primary force controlling erosion across the western Himalaya, at least over millennial time scales. This variation is preserved with no apparent lag in sediments from the delta, but not in the deep Arabian Sea, due to sediment buffering on the continental shelf.