A rock magnetic study on red palaeosols in Yun-Gui Plateau (Southwestern China) and evidence for uplift of Plateau
A rock magnetic study on red palaeosols in Yun-Gui Plateau (Southwestern China) and evidence for uplift of Plateau
复制标题
云贵高原红色古土壤岩石磁学研究及高原隆升证据
DOI：
10.1093/gji/ggt453
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发表时间：
2014-02
影响因子：
2.8
通讯作者：
Lu, S.G.
中科院分区：
文献类型：
--
作者：
Wang, S.Y;Lu, S.G.
利用岩石磁性、选择性化学溶解、差示 X 射线衍射 (DXRD) 和高分辨率透射电子显微镜 (HRTEM) 对中国西南云贵高原 (YGP) 红色古土壤的磁信号进行研究，以探讨红色古土壤作为高原古生成和隆升代理指标的潜力。红色古土壤的特征是强磁信号和深红色，色调为 5 YR（黄红色）。表土的低频磁化率 (χlf) 从 1500 × 10−8 到 2500 × 10−8m3kg−1 变化，从剖面的顶部到底部呈递减模式。磁性剖面显示，红色古土壤含有大量细粒超顺磁性（SP）颗粒，这归因于成土 SP 磁赤铁矿浓度较高。连二亚硫酸盐-柠檬酸盐-碳酸氢盐（DCB）程序可以选择性地溶解红色古土壤中的超细成土磁性矿物，质量特定频率依赖性磁化率（χfd）和DCB处理的χlf损失之间的高度相关性证明了这一点。 DCB 处理后的磁损失占原始磁化率的 87-95%。岩石磁性和DXRD表明，红色古土壤中的主要磁性矿物是成土SP/稳定单域（SP/SSD）磁赤铁矿。这些成土磁赤铁矿约占游离氧化铁的 1%。 HRTEM 观察显示了成土 SP（<~20-30 nm）和纯磁赤铁矿的证据。这些磁性颗粒的尺寸从几纳米到几十纳米不等，表现出这种矿物的典型晶体化学特征。磁性证据表明红色古土壤经历了强烈的成土过程。成土过程导致赤铁矿和磁赤铁矿的新形成，并导致磁化率和其他磁信号的大幅增加。因此，红色古土壤的岩石磁性可能会产生重要的古土壤信息和高原新构造运动的证据。目前的工作结果表明，红色古土壤可能是了解 YGP 隆起幅度和年龄的良好工具。
Magnetic signals of red palaeosols from the Yun-Gui Plateau (YGP), southwestern China, are studied using rock magnetism, selective chemical dissolution, differential X-ray diffraction (DXRD) and high-resolution transmission electron microscopy (HRTEM) in order to explore the potential of red palaeosol as a proxy indicator of paleogenesis and uplift of plateau. Red palaesols are characterized by highly magnetic signals and dark red color with a hue of 5 YR (yellow-red). The low-frequency magnetic susceptibility (χlf) of topsoils is shown to vary from 1500 × 10−8to 2500 × 10−8m3kg−1in a decreasing pattern from the top to bottom of the profile. Magnetic profiles reveal that the red palaeosols contain significant amount of fine-grained superparamagnetic (SP) grains, which is attributed to the higher concentration of pedogenic SP maghemite. The dithionite–citrate–bicarbonate (DCB) procedure can selectively dissolve ultrafine pedogenic magnetic minerals in the red palaeosols, as evidenced by the highly correlation between mass-specific frequency-dependent magnetic susceptibility (χfd) and χlf loss of DCB treatment. The magnetic loss after DCB treatment accounts for 87–95 per cent of the original susceptibility. Rock magnetism and DXRD reveal that the main magnetic mineral in the red palaeosols is the pedogenic SP/stable single domain (SP/SSD) maghemite. These pedogenic maghemites account for about 1 per cent of free iron oxides. HRTEM observations show the evidence of pedogenic SP (<∼20–30 nm) and pure maghemite. These magnetic particles vary from several to tens of nanometres in size and exhibit typical crystallochemical characteristics of this mineral. Magnetic evidence suggests that the red palaeosols experience a strongly pedogenic processes. Pedogenic processes result in the neoformation of hematite and maghemite, and causes a substantial increase in the magnetic susceptibility and other magnetic signals. Therefore, the rock magnetism of red palaeosols potentially yields significant palaeopedogenic information and evidence on the neotectonic movement of plateau. Results of the present work suggest that the red palaeosols could be a good tool for understanding the amplitude and the age of uplift in the YGP.
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影响因子：
64.8
作者：
L. Zhou;F. Oldfield;A. Wintle;S. Robinson;J. T. Wang
通讯作者：
L. Zhou;F. Oldfield;A. Wintle;S. Robinson;J. T. Wang
DOI：
--
发表时间：
2006
期刊：
Journal of Chengdu University
影响因子：
--
作者：
Lu Wei
通讯作者：
Lu Wei
DOI：
10.1029/2004eo200009
发表时间：
2004-05
期刊：
Eos, Transactions American Geophysical Union
影响因子：
--
作者：
J. Geissman
通讯作者：
J. Geissman
影响因子：
6.2
作者：
Shenggao Lu;Q. Xue;Lei Zhu;Jin-Yan Yu
通讯作者：
Shenggao Lu;Q. Xue;Lei Zhu;Jin-Yan Yu
影响因子：
3.1
作者：
Barrón, V;Torrent, J;de Grave, E
通讯作者：
de Grave, E