Variability of the temperature-dependent susceptibility of the Holocene eolian deposits in the Chinese loess plateau: A pedogenesis indicator
Variability of the temperature-dependent susceptibility of the Holocene eolian deposits in the Chinese loess plateau: A pedogenesis indicator
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DOI：
10.1016/s1464-1895(01)00135-1
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发表时间：
2001-01-01
期刊：
影响因子：
--
通讯作者：
Singer, MJ
中科院分区：
文献类型：
--
作者：
Deng, C;Zhu, R;Singer, MJ
我们采用局部加热/冷却方法（Van Velzen and Dekkers, 1999）对中国黄土高原全新世黄土代表性样品进行了分析，以研究热处理过程中的磁性矿物学变化。磁化率的温度依赖性（TDS）结果表明，在加热和冷却过程中，磁铁矿和磁赤铁矿是黄土高原全新世风成沉积中主要的铁磁性矿物。TDS测量结果表明，热致蚀变的程度与土壤作用密切相关，土壤作用是气候的函数，因此蚀变本身可能是一个有用的气候指标。黄土高原NW-SE样带的TDS结果表明，较强的成土作用导致磁铁矿含量较高，热处理过程中磁化率降低幅度较大。这一行为似乎表明中国黄土和古土壤中成土磁铁矿的最终产物是磁赤铁矿，磁赤铁矿对中国风成矿床磁化率的增强起着重要作用。2001爱思唯尔科学有限公司版权所有。
We used a partial heating/cooling method (Van Velzen and Dekkers, 1999) for the analysis of representative samples of the Holocene loess of the Chinese loess plateau, in order to investigate magnetic mineralogical changes during thermal treatment. The temperature-dependence of susceptibility (TDS) results show significant alteration of magnetic phases during heating and cooling, and provide further evidence that magnetite and maghemite are the dominant ferrimagnetic minerals in the Holocene eolian deposits of the loess plateau. The TDS measurements suggest that the degree of the thermally-induced alteration is closely related to pedogenesis, which is a function of climate, and thus the alteration itself could be a useful climate indicator. Our TDS results along a NW-SE transect in the loess plateau suggest that stronger pedogenesis results in higher content of maghemite and greater susceptibility decrease during thermal treatment. This behavior seems to indicate that the final product of pedogenic magnetite in Chinese loess and paleosols is maghemite, which plays an important role in the enhancement of the magnetic susceptibility of Chinese eolian deposits. (C) 2001 Elsevier Science Ltd. All rights reserved.