Sea level-controlled sediment transport to the eastern Arabian Sea over the past 600 kyr: Clay minerals and Sr-Nd isotopic evidence from IODP site U1457
Sea level-controlled sediment transport to the eastern Arabian Sea over the past 600 kyr: Clay minerals and Sr-Nd isotopic evidence from IODP site U1457
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过去 600 凯尔期间海平面控制的沉积物向阿拉伯海东部输送：来自 IODP 站点 U1457 的粘土矿物和 Sr-Nd 同位素证据
DOI：
10.1016/j.quascirev.2018.12.006
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发表时间：
2019
影响因子：
4
通讯作者：
Kumar Anil
中科院分区：
文献类型：
--
作者：
Yu Zhaojie;Colin Christophe;Wan Shiming;Saraswat Rajeev;Song Lina;Xu Zhaokai;Clift Peter;Lu Huayu;Lyle Mitchell;Kulhanek Denise;Hahn Annette;Tiwari Manish;Mishra Ravi;Miska Serge;Kumar Anil
阿拉伯海沉积的长海相层序适合从源-汇角度研究沉积动力学的轨道敏感性。通过对阿拉伯海东部Laxmi盆地IODP U1457站沉积物碎屑组分的粘土矿物学和Sr-Nd同位素组成分析，确定了沉积物来源，并重建了近60万年来印度河深海扇的高分辨率沉积物输出记录。87 Sr/86 Sr比值（从0.7154到0.7255不等）和εNd（从−12.9到−9.5不等）意味着沉积物的混合不仅来自印度河，也来自德干圈闭的河流。蒙皂石/（伊利石+伊利石）的比率结合Sr单键Nd同位素的变化允许重建来自印度河（主要是伊利石，伊利石和高岭石）和德干圈闭（蒙皂石）的沉积物的相对比例的过去的变化。小波和交叉谱分析进一步揭示，沉积物输送到东阿拉伯海，因为600 kyr主要是由海平面变化的偏心率（100 kyr）带，而印度夏季风可能有助于适度的岁差（23 kyr）带。εNd和浊积岩频率表明，更多的浊积岩事件与印度河源沉积物在IODP站点U1457在海平面低水位，这可能反映了重新连接的深海通道的印度河河口和/或改造以前沉积的印度河沉积物位于北部。
Long marine sequences deposited in the Arabian Sea are suitable to study the orbital sensitivity of sediment dynamics from a source-to-sink perspective. The clay mineralogy and Srsingle bondNd isotopic compositions have been analyzed for the detrital fraction of sediments from IODP Site U1457 located in the Laxmi basin, eastern Arabian Sea to constrain the sediment sources and reconstruct a high-resolution record of sediment export to the Indus deep-sea fan over the past 600 kyr. The87Sr/86Sr ratio (varying from 0.7154 to 0.7255) and εNd (varying from −12.9 to −9.5) imply a mixing of sediments derived from not only the Indus River but also the rivers draining the Deccan Traps. The variations in the smectite/(illite + chlorite) ratio combined with Srsingle bondNd isotopes permit the reconstruction of past changes in the relative proportions of sediments derived from the Indus River (mainly illite, chlorite and kaolinite) and the Deccan Traps (smectite). The wavelet and cross-spectral analyses further reveal that sediment transport to the eastern Arabian Sea since 600 kyr is mainly dominated by sea-level variations in the eccentricity (100-kyr) band, while the Indian summer monsoon might contribute moderately to the precession (23-kyr) band. The εNd and turbidite frequency indicate that more turbidite events are associated with Indus River-sourced sediments at IODP Site U1457 during sea-level lowstands, which might reflect a reconnection of deep-sea channels to the Indus River mouth and/or reworking of previously deposited Indus River sediments located northward.