U-Pb ages of detrital zircon and provenances of Red Clay in the Chinese Loess Plateau
U-Pb ages of detrital zircon and provenances of Red Clay in the Chinese Loess Plateau
复制标题
中国黄土高原碎屑锆石U-Pb年龄及红粘土物源
DOI：
10.1016/j.jseaes.2017.02.014
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发表时间：
2017-05-01
影响因子：
3
通讯作者：
Zhang, Yunxiang
中科院分区：
文献类型：
--
作者：
Gong, Hujun;Xie, Wenbin;Zhang, Yunxiang
位于我国中部的黄土高原主要包括两个层序：第四纪黄土-古土壤层序和晚中新世-上新世红粘土层序。第四纪黄土-古土壤序列中碎屑锆石U-Pb年龄表明，中亚干旱化的空间格局主要建立在第四纪早期。下伏红粘土层碎屑锆石U-Pb年龄表明，除8 Ma和5.5 ~ 4 Ma的时期外，晚中新世以来的粉尘主要来源于北方源区。这两个时期分别对应于北太平洋沙尘沉降的增加和减少，归因于柴达木盆地（在CLP西部）的晚中新世干旱化和塔里木盆地（在CLP西部）的早上新世干旱化。青藏高原东北部的隆升是导致柴达木盆地北太平洋沙尘通量增加的主要原因。这种隆升也控制了晚中新世中亚地区的气候和环境变化。本文重点研究了晚中新世-上新世中亚干旱化的动力学过程。(C)2017爱思唯尔有限公司版权所有
The Chinese Loess Plateau (CLP), which is located in the central part of China, mainly contains two sequences: the Quaternary loess-paleosol sequence and the late Miocene-Pliocene Red Clay sequence. U-Pb ages of detrital zircon from the Quaternary loess-paleosol sequences indicate that the current spatial pattern of central Asian aridification was largely established during the early Quaternary. U-Pb ages of detrital zircon from the underlying Red Clay sequences demonstrate that the northern source regions were important contributors for the dust since the late Miocene, except for the periods of similar to 8 Ma and similar to 5.5 to 4 Ma. These two periods correspond to increased and decreased dust deposition in the North Pacific, respectively, ascribed to the late Miocene aridification of the Qaidam Basin (in the west of the CLP) and the early Pliocene aridification of the Tarim Basin (in the west of the CLP). We attribute the increase of the Qaidam Basin-derived North Pacific dust fluxes to the uplift of the NE Tibetan Plateau. Such uplift also controlled the climatic and environmental changes in central Asian during the late Miocene. This study highlights the dynamical process of the central Asian aridification during the late Miocene-Pliocene. (C) 2017 Elsevier Ltd. All rights reserved.