中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Late cenozoic chemical weathering and environmental changes recorded in the Co Ngoin sediments, central Qinghai-Tibet Plateau

文献类型:期刊论文

作者Chen, SY; Jin, ZD; Wang, SM; Shen, J
刊名ACTA GEOLOGICA SINICA-ENGLISH EDITION
出版日期2005
卷号79期号:3页码:384-391
关键词Qinghai-Tibet Plateau Co Ngoin Rb/Sr Zr/Rb delta C-13 TOC environmental evolution
ISSN号1000-9515
英文摘要A series of faulted inland basins were developed in the central Qinghai-Tibet Plateau, among which the Co Ngoin Basin containing thick lacustrine sediments is located in the peripheral area of the Indian monsoon. In this paper, we present the weathering history and paleoclimatic changes in the last 2.8 Ma based on studies of high-resolution temporal distributions of Sr, Rb and Zr concentrations, Rb/Sr and Zr/Rb ratios and delta(13)C and TOC for the Co Ngoin sediments, in combination with the sediment properties, grain size distribution and clay mineralogy. The sedimentary records indicate three environmental stages in the last 2.8 Ma. At the Core depth of 197-170 m (about 2.8-2.5 Ma), low-intensity chemical weathering in the Co Ngoin catchment was experienced under warm-dry to cool-wet climate conditions with relatively low Sr concentration and high Rb/Sr and Zr/Rb ratios. The sudden occurrence of both subalpine coniferous forest and coarse sand and gravel sediments in the Co Ngoin core reflects a strong tectonic uplift. The high Sr concentrations and low Rb/Sr and Zr/Rb ratios reflect a relatively strong chemical weathering between 2.5 Ma and 0.8 Ma (at the core depth of 170-38.5 m) under a temperate/cool and wet climate, characterized by mud and silt with fine sand, probably indicating a stable process of denudation and planation of the plateau. Above the depth of 38.5 in (about 0.8-0 Ma), the coarsening of sediments indicates a strong tectonic uplift and a relatively low intensity of chemical weathering as supported by the record of sediments having relatively low Sr concentrations and high Rb/Sr and Zr/Rb ratios. Since then, the plateau has taken the shape of the modem topographic pattern above 4000 m a.s.l.
公开日期2012-03-07
源URL[http://159.226.73.51/handle/332005/2845]  
专题南京地理与湖泊研究所_湖泊室
推荐引用方式
GB/T 7714
Chen, SY,Jin, ZD,Wang, SM,et al. Late cenozoic chemical weathering and environmental changes recorded in the Co Ngoin sediments, central Qinghai-Tibet Plateau[J]. ACTA GEOLOGICA SINICA-ENGLISH EDITION,2005,79(3):384-391.
APA Chen, SY,Jin, ZD,Wang, SM,&Shen, J.(2005).Late cenozoic chemical weathering and environmental changes recorded in the Co Ngoin sediments, central Qinghai-Tibet Plateau.ACTA GEOLOGICA SINICA-ENGLISH EDITION,79(3),384-391.
MLA Chen, SY,et al."Late cenozoic chemical weathering and environmental changes recorded in the Co Ngoin sediments, central Qinghai-Tibet Plateau".ACTA GEOLOGICA SINICA-ENGLISH EDITION 79.3(2005):384-391.

入库方式: OAI收割

来源:南京地理与湖泊研究所

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