Pronounced changes in atmospheric circulation and dust source area during the mid-Pleistocene as indicated by the Caotan loess-soil sequence in North China
Pronounced changes in atmospheric circulation and dust source area during the mid-Pleistocene as indicated by the Caotan loess-soil sequence in North China
复制标题
华北草滩黄土-土壤层序显示中更新世大气环流和尘源区的显着变化
DOI：
10.1016/j.quaint.2014.09.075
复制
发表时间：
2015-06
影响因子：
2.2
通讯作者：
Yansong Qiao
中科院分区：
文献类型：
--
作者：
Shasha Peng;Junyi Ge;Chaozhu Li;Zongxiu Liu;Lin Qi;Yuanlong Tan;Yu Cheng;Chenglong Deng;Yansong Qiao
中国北部第四纪黄土-土壤序列对示踪大气环流变化具有重要价值。本文测量了青藏高原东北缘草滩(CT)黄土-土壤序列的磁化率各向异性(AMS)，并分析了典型样品的石英颗粒表面结构特征。AMS结果表明为原生沉积磁性组构，未受成壤作用的明显干扰。DEC-Kmax值表明，自∼300ka以来，地表主要风向从近N-S向西-E方向显著转移，而石英颗粒的表面结构特征表明，来自TP的河流冰川沉积物的贡献同时增加。由于在300ka附近没有明显的气候变化证据，我们将大气环流和沙尘源区的同时代变化归因于中更新世期间TP的抬升和由此导致的气候降温。TP的冷却可能不仅导致高原季风的增强，而且还导致高原冰川的显著堆积，这将导致下伏岩石的物理侵蚀加速，从而增加了要输送到研究地点的细粒河流冰川沉积物的数量。
The Quaternary loess-soil sequence in North China is of significant value for tracing variations in atmospheric circulation. In this study, we measured the anisotropy of magnetic susceptibility (AMS) of the Caotan (CT) loess-soil sequence from the northeastern margin of the Tibetan Plateau (TP) and analyzed the surface textural features of quartz grains of representative samples. The AMS results indicate a primary sedimentary magnetic fabric without significant disturbance by pedogenesis. The Dec-Kmaxvalues indicate a significant shift of the dominant surface wind direction from nearly N–S to W–E since ∼300 ka, while the surface textural features of the quartz grains indicate an increase in the contribution from fluvioglacial sediments derived from the TP at the same time. As there is no evidence of significant climatic changes around 300 ka, we attribute the coeval changes of atmospheric circulation and dust source area to the uplift of the TP during the mid-Pleistocene and the resulting climatic cooling. Cooling of the TP may have led not only to the enhancement of the plateau monsoon but also to the significant accumulation of plateau glaciers, which would have resulted in accelerated physical erosion of the underlying rocks, thus increasing the quantity of fine-grained fluvioglacial sediments to be transported to the study site.
登录
查看更多内容
影响因子：
2.9
作者：
M. Yokokawa;S. Franz
通讯作者：
M. Yokokawa;S. Franz
从黄土沉积物磁化率各向异性变化重建华北末次冰期古风向空间变化
影响因子：
2.9
作者：
Junyi Ge;Zhengtang Guo;Deai Zhao;Ying Zhang;Tao Wang;Liang Yi;Chenglong Deng
通讯作者：
Chenglong Deng
影响因子：
4
作者：
Z. Ding;Z. Yu;N. Rutter;Tung-sheng Liu
通讯作者：
Z. Ding;Z. Yu;N. Rutter;Tung-sheng Liu
影响因子：
2.3
作者：
L. Thistlewood;Sun Jianzhong
通讯作者：
L. Thistlewood;Sun Jianzhong
影响因子：
--
作者：
Y. Qiao;Zhizhong Zhao;Yan Wang;Jianli Fu;Shubing Wang;F. Jiang
通讯作者：
Y. Qiao;Zhizhong Zhao;Yan Wang;Jianli Fu;Shubing Wang;F. Jiang