Rock magnetism, iron oxide mineralogy and geochemistry of Quaternary red earth in central China and their paleopedogenic implication
Rock magnetism, iron oxide mineralogy and geochemistry of Quaternary red earth in central China and their paleopedogenic implication
复制标题
中国中部第四纪红土岩石磁性、氧化铁矿物学、地球化学及其古土壤意义
DOI：
10.1016/j.palaeo.2013.04.010
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发表时间：
2013-06
期刊：
影响因子：
--
通讯作者：
Lu, S.G.
中科院分区：
文献类型：
--
作者：
Wang, S.Y.;Lin, S.;Lu, S.G.
本文对中国中部某第四纪红壤的岩石磁性、氧化铁矿物学和地球化学进行了详细的研究。青藏高原磁性剖面具有明显的垂直变化特征：均匀红粘土剖面(0.2m~2m)具有较高的磁化率(χ)，而蠕动红粘土剖面(2~6m)具有很低的χ(<；30×10−8m3 kg−1)。岩石磁性和差示X射线衍射分析表明，磁铁矿/磁赤铁矿和赤铁矿是URC剖面的主要磁性载体。QRE的主要元素Fe_2O_3和Al_2O_3随着深度的增加而增加，而SiO_2的含量则随着深度的增加而减少，表明活动性元素的淋溶和非活动性元素的富集性。与URC相比，VRC对Na、Mg、K、Mg的亏损较大，表明风化强度较强。二亚硫酸盐-柠檬酸-碳酸氢盐(DCB)浸提铁(FED)、FED/总氧化铁(Fe/Fet)和QRE的风化指数证实，VRC经历了比URC更强的成壤作用。VRC中强烈的成壤作用导致了高磁性磁赤铁矿向弱磁性赤铁矿的转变，这是VRC的弱磁性和硬磁性行为的原因。我们的研究表明，VRC经历了炎热的气候和干燥的季节，随后是温暖和潮湿的季节。高磁性磁赤铁矿向弱磁性赤铁矿转变所导致的VRC剖面的磁性还原似乎是青藏高原重要的古成矿过程。认为QRE的硬等温剩余磁化强度(HIRm)和Sirm/χ可用于古造山作用的分析。
This paper presents a detailed investigation on the rock magnetism, iron oxide mineralogy and geochemistry of a Quaternary red earth (QRE) in central China. The magnetic profile of QRE showed a characteristic vertical variation pattern: the uniform red clay (URC) section (0.2–2m) of the profile had a higher magnetic susceptibility (χ) while vermiculated red clay (VRC) section (2–6m) had a very low χ (<30×10−8m3kg−1). Rock magnetism and differential XRD analysis revealed that magnetite/maghemite and hematite were the main magnetic carriers in the URC section. The major elements Fe2O3and Al2O3of QRE increased with depth while the SiO2content decreased with depth, indicating a leaching of the mobile elements and an enrichment of the immobile elements. In comparison with the URC, the VRC has a greater depletion in the content of Na, Mg, K and Mg, indicating a stronger weathering intensity. The dithionite–citrate–bicarbonate (DCB) extracted iron (Fed), the ratio of Fed to total iron oxide (Fe/Fet), and the weathering indices of QRE confirmed that the VRC had experienced a stronger pedogenesis than the URC. Strong pedogenesis in the VRC resulted in a transformation of the highly magnetic maghemite to the weakly magnetic hematite, which was responsible for the weak magnetism and hard magnetic behavior of the VRC. Our studies suggest that the VRC had experienced a hot climate with a dry season following one that was warm and moister. Magnetic reduction of the VRC section resulting from the transformation of highly magnetic maghemite to weakly magnetic hematite appeared to be an important paleopedogenic process in the QRE. We concluded that the magnetic parameters, hard isothermal remanent magnetization (HIRM) and SIRM/χ of QRE, can be used for the analysis of paleopedogenic processes.
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影响因子：
2.5
作者：
Xuefeng Hu;Wenlong Jiang;W. Ye;Ming-Neng Shen;Weiguo Zhang;Hong-bo Wang;Cheng Lu;Lidong Zhu
通讯作者：
Xuefeng Hu;Wenlong Jiang;W. Ye;Ming-Neng Shen;Weiguo Zhang;Hong-bo Wang;Cheng Lu;Lidong Zhu
影响因子：
3.1
作者：
Barrón, V;Torrent, J;de Grave, E
通讯作者：
de Grave, E
DOI：
10.1007/978-1-4612-5046-3_5
发表时间：
1958
期刊：
--
影响因子：
--
作者：
U. Schwertmann
通讯作者：
U. Schwertmann
影响因子：
1.7
作者：
U. Schwertmann
通讯作者：
U. Schwertmann
影响因子：
2.8
作者：
Liu, Caicai;Deng, Chenglong;Yuan, Baoyin
通讯作者：
Yuan, Baoyin