• 责任者：Huang Xiangtong (State Key Laboratory of Marine Geology ; School of Ocean and Earth Sciences ; Tongji University ; Shanghai 200092 ; China) ; Zheng Hongbo
• 刊名：Quaternary Sciences
• 出版年：2013
• 卷期：33(4)
• 关键词：宇宙成因核素测年 ; cosmogenic nuclide dating ; 河流沉积物 ; stream sediments ; 侵蚀速率 ; erosion rates ; 长江 ; Yangtze River
• 页码：p.671-683
• 图表：3 illus., 2 tables, 69 refs.
• 分类号：1400
• issnNo：ISSN1001-7410
• isbnNo：CN11-2708/P

     The surface of the Earth is always subjected to erosion.Understanding the erosion processes and rates is helpful to recognize many important geological processes and evolution.This paper presents a research on cosmogenic nuclide 10 Be in the Yangtze Riverine sediments,with scientific objectives to quantitatively estimate average erosion rates in the Yangtze River catchment and its sub-catchments,and to provide a natural baseline that is helpful in understanding the source to sink processes of sediments and in assessing humans impacts on soil erosion.The analyzed samples were taken from surface sediments in the Yangtze River main-stream and major tributaries.The results show that 10 Be concentration decreases downstream in the mainstream from Jinshajiang River to the Yangtze River estuary,but the 10 Be concentrations in tributaries are relatively low and stable.This characteristic might be attributed to 10 Be production and erosion rate.The highest concentration of 10 Be occurs in the upper reaches,with inputs of lower-concentration sediments,causing a phenomenon of high in the west but low in the east reaches.The estimated erosion rates based on 10 Be show that the erosion rates are low in the upper reaches of Jinshajiang River（44.7~48.1m/Ma）,relatively variable in the middle reaches fluctuating in the range of 65.7~175.0m/Ma,and rather stable in the Yangtze River estuary（50~60m/Ma）.The erosion rates are considerably higher in the tributaries than in the mainstream.The region with lowest erosion rate is Wujiang River catchment,which average erosion rate is in the range of 10~30m/Ma.The comparison of erosion rate between 10 Be and hydrological gauge data illustrate that the erosion rates estimated by hydrological gauge are generally higher than those by 10 Be.The high erosion rates in the Daduhe River-Minjiang River catchment are related to natural factors,such as tectonic,relief,lithology and climate.However,the erosion conditions of the rest sub-catchments,particularly those in the east of Daduhe River-Mingjiang River,are mainly impacted by human activities that have caused erosion rates estimated by hydrological gauge exceeding those estimated by 10 Be.