Drainage evolution of the Heihe River in western Hexi Corridor, China, derived from sedimentary and magnetostratigraphic results
Drainage evolution of the Heihe River in western Hexi Corridor, China, derived from sedimentary and magnetostratigraphic results
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DOI：
10.1016/j.quascirev.2016.08.036
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发表时间：
2016-10
影响因子：
4
通讯作者：
B. Pan;Dianbao Chen;Xiaofei Hu;Xilin Cao;Jinjun Chen;Junwei Mao
中科院分区：
文献类型：
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作者：
B. Pan;Dianbao Chen;Xiaofei Hu;Xilin Cao;Jinjun Chen;Junwei Mao
重建黑河的演化过程可以为巴丹吉林沙漠的形成提供证据，加深对沉积盆地充填以及构造、流域演化与环境变化关系的认识。为此，在黑河漫滩上钻取了两个平行岩心（DWJ和XKJD，深度分别为140和68.2 m）。岩心沉积层序相分析表明，在~ 133.3和~ 68 m深度，沉积环境由湖泊体系转变为三角洲体系，最终转变为河流体系。磁地层结果显示，DWJ和XKJD岩心的年龄分别约为1.75 Ma和1.12 Ma，两个岩心从三角洲环境向河流环境过渡的年龄约为1.1 Ma。1.1 Ma左右沉积环境的变化是由一体化黑河的形成引起的。一体化的黑河可能是由于北祁连山和龙寿山的隆升而形成的河流捕获和河流改道等机制。研究表明，黑河、石羊河等大型内陆河的形成在黄土高原和沙漠的演变过程中发挥了重要作用。
The uplifting of the Tibetan Plateau has significantly changed the environment in surrounding areas by delivering abundant water and sediment. The Heihe River draining the Qilian Shan in the NE Tibetan Plateau acts as a dominant sediment routing system from the uplifted NE Tibetan Plateau to the Hexi Corridor as well as the Badain Jaran Desert. Reconstructing the evolution of the Heihe River could provide evidence for the birth of the Badain Jaran Desert and enhance the understanding of sedimentary basin fill and the relationship between tectonism, drainage evolution and environmental changes. With this aim, two parallel cores (DWJ and XKJD with depths of 140 and 68.2 m, respectively) were drilled in the floodplain of the Heihe River. The facies analysis of the sedimentary sequences from the drilling cores showed that the sedimentary environment changed from the lake system to a delta system and finally to a fluvial system at the depths of ∼133.3 and ∼68 m, respectively. The magnetostratigraphic results revealed ages of approximately 1.75 and 1.12 Ma for the DWJ and XKJD cores, respectively, and an age of approximately 1.1 Ma for the transition from delta to fluvial environment in both the cores. The change of the sedimentary environment at approximately 1.1 Ma was caused by the formation of the integrated Heihe River. The integrated Heihe River may have developed via mechanisms such as river capture and river diversion due to the uplifting of the North Qilian Shan and the Longshou Shan. The present study suggested that the formation of large inland rivers, such as the Heihe River and the Shiyang River in NW China, played an important role in the evolution of the deserts and the Loess Plateau.