Aeolian dust supply from the Yellow River floodplain to the Pleistocene loess deposits of the Mangshan Plateau, central China: Evidence from zircon U-Pb age spectra
Aeolian dust supply from the Yellow River floodplain to the Pleistocene loess deposits of the Mangshan Plateau, central China: Evidence from zircon U-Pb age spectra
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黄河泛滥平原向中国中部邙山高原更新世黄土沉积物提供的风成粉尘：来自锆石U - Pb年龄谱的证据
DOI：
10.1016/j.quascirev.2018.01.001
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发表时间：
2018-02
影响因子：
4
通讯作者：
Yuan Shang;Yuan Shang;M. Prins;C. Beets;A. Kaakinen;Y. Lahaye;N. Dijkstra;D. S. Rits;Bin Wang;Hongbo Zheng;R. Balen
中科院分区：
文献类型：
--
作者：
Yuan Shang;Yuan Shang;M. Prins;C. Beets;A. Kaakinen;Y. Lahaye;N. Dijkstra;D. S. Rits;Bin Wang;Hongbo Zheng;R. Balen
沿着黄河下游南岸的莽山黄土高原（MLP）厚层黄土-古土壤序列提供了高分辨率的第四纪气候变化记录。此外，在黄土序列的上部，古土壤层S2之上，推断出粒度和累积速率的大幅增加。利用黄土粒度数据的端元模拟和单颗粒锆石U-Pb测年，研究了MLP长期粉尘供应的来源，并探讨了S2（约240 ka）以来黄土沉积物输沙量突然增加和粗化的机制。我们的研究结果表明，黄河下游河漫滩，直接北部的MLP，作为一个主要的灰尘供应高原至少自沉积的黄土单元L9和间接建议，黄河的整合和消失的三门古湖发生在L9（约900 ka）。古土壤单元S2之上的莽山序列沉积学的突变可能是由于240 ka前后渭河盆地的构造运动（启动）导致河流沉积物向黄河下游输送的通量增加所致。沉积物粗化的原因可能是自古土壤S2沉积以来，黄河下游河漫滩向MLP逐渐南移。迁移的证据是形成了一个令人印象深刻的悬崖，可能是由构造倾斜的河漫滩地区。
The thick loess-palaeosol sequences in the Mangshan Loess Plateau (MLP; central China) along the south bank of the lower reach of the Yellow River provide high-resolution records of Quaternary climate change. In addition, substantial increases in grain-size and accumulation rate have been inferred in the upper part of the loess sequence, above palaeosol layer S2. This study investigates the sources of the long-term dust supply to the MLP and explores the mechanism behind the sudden increase in sediment delivery and coarsening of the loess deposits since S2 (∼240 ka) by using end member modelling of the loess grain-size dataset and single-grain zircon U-Pb dating. Our results indicate that the lower Yellow River floodplain, directly north of the MLP, served as a major dust supply for the plateau at least since the deposition of loess unit L9 and indirectly suggest that the integration of the Yellow River and the disappearance of the Sanmen palaeolake took place before L9 (∼900 ka). The sudden change in sedimentology of the Mangshan sequence above palaeosol unit S2 may result from an increased fluvial sediment flux being transported to the lower reaches of the Yellow River because of tectonic movements (initiated) in the Weihe Basin around 240 ka. Furthermore, sediment coarsening can be explained by the gradual southward migration of the lower Yellow River floodplain towards the MLP since the deposition of palaeosol S2. The migration is evidenced by the formation of an impressive scarp, and is likely caused by tectonic tilting of the floodplain area.