Electrical conductivity anisotropy in partially molten peridotite under shear deformation

	Electrical conductivity anisotropy in partially molten peridotite under shear deformation
	Baohua Zhang; Takashi Yoshino; Daisuke Yamazaki; Geeth Manthilake; Tomoo Katsura
	2014
发表期刊	Earth and Planetary Science Letters
卷号	405 期号:1 页码:98-109
摘要	The electrical conductivity of partially molten peridotite was measured during deformation in simple shear at 1 GPa in a DIA type apparatus with a uniaxial deformation facility. To detect development of electrical anisotropy during deformation of partially molten system, the electrical conductivity was measured simultaneously in two directions of three principal axes: parallel and normal to the shear direction on the shear plane, and perpendicular to the shear plane. Impedance spectroscopy measurement was performed at temperatures of 1523 K for Fe-bearing and 1723 K for Fe-free samples, respectively, in a frequency range from 0.1 Hz to 1 MHz. The electrical conductivity of partially molten peridotite parallel to shear direction increased to more than one order of magnitude higher than those normal to shear direction on the shear plane. This conductivity difference is consistent with the magnitude of the conductivity anisotropy observed in the oceanic asthenosphere near the Eastern Pacific Rise. On the other hand, conductivity perpendicular to the shear plane decreased gradually after the initiation of shear and finally achieved a value close to that of olivine. The magnitude and development style of conductivity anisotropy was almost the same for both Fe-bearing and Fe-free melt-bearing systems, and also independent of shear strain. However, such conductivity anisotropy was not developed in melt-free samples during shear deformation, suggesting that the conductivity anisotropy requires a presence of partial melting under shear stress. Microstructural observations of deformed partially molten peridotite samples demonstrated that conductivity anisotropy was attributed to the elongation of melt pockets parallel to the shear direction. Horizontal electrical conductivity anisotropy revealed by magnetotelluric surveys in the oceanic asthenosphere can be well explained by the realignment of partial melt induced by shear stress.
关键词	Electrical Conductivity Anisotropy Partial Melt Peridotite Shear Deformation
学科领域	地球深部物质与流体作用地球化学
收录类别	SCI
语种	英语
文献类型	期刊论文
条目标识符	http://ir.gyig.ac.cn/handle/352002/5282
专题	地球内部物质高温高压实验室_地球内部物质高温高压实验室_期刊论文
推荐引用方式 GB/T 7714	Baohua Zhang,Takashi Yoshino,Daisuke Yamazaki,et al. Electrical conductivity anisotropy in partially molten peridotite under shear deformation[J]. Earth and Planetary Science Letters,2014,405(1):98-109.
APA	Baohua Zhang,Takashi Yoshino,Daisuke Yamazaki,Geeth Manthilake,&Tomoo Katsura.(2014).Electrical conductivity anisotropy in partially molten peridotite under shear deformation.Earth and Planetary Science Letters,405(1),98-109.
MLA	Baohua Zhang,et al."Electrical conductivity anisotropy in partially molten peridotite under shear deformation".Earth and Planetary Science Letters 405.1(2014):98-109.

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