Magnetic fabric from red clay sediments in the Chinese Loess Plateau.
Magnetic fabric from red clay sediments in the Chinese Loess Plateau.
复制标题
中国黄土高原红粘土沉积物的磁性组构
DOI：
10.1038/srep09706
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发表时间：
2015-04-27
影响因子：
4.6
通讯作者：
Li J
中科院分区：
文献类型：
--
作者：
Gong H;Zhang R;Yue L;Zhang Y;Li J
中国北方广泛分布的风成红粘土，被认为是晚中新世以来古东亚季风系统的开始。对黄土高原7- 2.6Ma和11- 2.6Ma两个连续红粘土序列进行了研究，以确定风成沉积物原始组构的磁性取向和颗粒排列。风成红粘土序列的AMS的西北方向平行于物质的传输方向，这不同于模式，即从上覆黄土-古土壤序列的空气中的灰尘被东亚冬季风输送和固定的东亚夏季风。我们的研究结果进一步揭示，今天的气候和空气流通模式不同于前第四纪，并可能提供证据的盛行风沉积过程中的红粘土。
Well-distributed eolian red clay in a wide area of northern China is believed to imply the onset of an ancient East Asian monsoon system since Late Miocene. Two continuous red clay sequences spanning the time interval 7–2.6 Ma and 11–2.6 Ma in the Chinese Loess Plateau was investigated to determine the magnetic orientation and grain alignment in the primary fabric of eolian sediments. The north-westerly orientation of the AMS of the eolian red clay sequences parallels the material transportation direction, which differs from the model that suggests that airborne dust from overlying loess-paleosol sequences were transported by the East Asian winter monsoon and fixed by the East Asian summer monsoon. Our results further reveal that present-day climate and air circulation patterns differ from those of the pre-Quaternary, and may provide evidence of a prevailing wind during deposition of the red clay.