Chemical Weathering Intensity and Terrigenous Flux in South China during the Last 90,000 Years—Evidence from Magnetic Signals in Marine Sediments
Chemical Weathering Intensity and Terrigenous Flux in South China during the Last 90,000 Years—Evidence from Magnetic Signals in Marine Sediments
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DOI：
10.3389/feart.2016.00047
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发表时间：
2016-04
影响因子：
2.9
通讯作者：
Xiaoqiang Yang;Xuechao Peng;X. Qiang;Niu Li;Qixian Zhou;Yuejun Wang
中科院分区：
文献类型：
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作者：
Xiaoqiang Yang;Xuechao Peng;X. Qiang;Niu Li;Qixian Zhou;Yuejun Wang
化学风化的程度受气候的强烈影响。我们提出了与南海北方部分的元素比值相关的磁性特征，以表明化学风化强度与过去9万年季风变化之间的联系。代表海洋沉积物中高磁化率矿物变化的磁性参数IRMAF 80 mT/SIRM，以及Al 2 O3/TiO 2和化学蚀变指数（CIA），显示了84-40 kyr亚洲季风增强和气候变暖期间强烈的化学和物理风化作用。高磁化率，TiO 2含量，和相对较粗的磁性矿物颗粒（相对较低的ARM/SIRM比）也表明更多的陆源碎屑通量导致的物理侵蚀和河流的运输能力增强。在40-15 kyr期间，低IRMAF 80 mT/SIRM以及化学代用指标表明弱风化，气候变冷，降水减少。
The level of chemical weathering is strongly affected by climate. We presented magnetic properties associated with element ratios from the northern part of the South China Sea to denote links between chemical weathering intensity and monsoon changes in the previous 90,000 years. The magnetic parameter IRMAF80mT/SIRM, representing the variations of high coercivity minerals in marine sediments accompanied with the Al2O3/TiO2 and the Chemical Index of Alteration (CIA), demonstrates strong chemical and physical weathering processes during the last 84-40 kyr when intensified Asian monsoon and warm climate occurred. High susceptibility, TiO2 content, and relatively coarser magnetic mineral grain (relatively low ARM/SIRM ratio) also suggest more terrigenous clastic flux resulting from intensified physical erosion and river transport ability. During the 40-15 kyr period, a low IRMAF80mT/SIRM as well as chemical proxies indicate weak weathering as the climate cooled and precipitation decreased.