High and highly anisotropic electrical conductivity of the asthenosphere due to hydrogen diffusion in olivine

	High and highly anisotropic electrical conductivity of the asthenosphere due to hydrogen diffusion in olivine
	LidongDai; Shun-ichiroKaratoa
	2014
发表期刊	Earth and Planetary Science Letters
卷号	408 期号:1 页码:79-86
摘要	Experimental studies on electrical conductivity in hydrated olivine had been made only at relatively low temperatures. The extrapolation of these data to asthenosphere temperatures shows that explaining high and highly anisotropic conductivity by hydrogen is difficult. We present new experimental results on the electrical conductivity in hydrated olivine single crystals measured under a broader temperature range than before (T (temperature) = 573-1373 K at P (pressure) = 4 GPa). The new results agree well with the previous results at low temperatures (T <900 K), whereas at higher temperatures (T > 1000 K) substantial deviations from the previous results are observed: (i) anisotropy in conductivity increases with temperature, and (ii) activation energies at high temperature regime are substantially higher than those at lower T. The high temperature behavior is consistent with a model invoking diffusion of two-protons at M-site vacancy, whereas the low temperature behavior suggests conduction by more mobile species such as free proton. The present results (i) explain the discrepancy between different previous studies conducted under different temperature regimes, and (ii) show that most of geophysical observations on the electrical conductivity in the asthenosphere including the high and highly anisotropic conductivity can be explained by high water content in the asthenosphere that is consistent with the geochemical model. Combining with a previous model of low seismic wave velocity of the asthenosphere, a subsolidus model invoking the role of hydrogen provides a unified explanation for the geophysical anomalies of the asthenosphere.
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/352002/6014
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	LidongDai,Shun-ichiroKaratoa. High and highly anisotropic electrical conductivity of the asthenosphere due to hydrogen diffusion in olivine[J]. Earth and Planetary Science Letters,2014,408(1):79-86.
APA	LidongDai,&Shun-ichiroKaratoa.(2014).High and highly anisotropic electrical conductivity of the asthenosphere due to hydrogen diffusion in olivine.Earth and Planetary Science Letters,408(1),79-86.
MLA	LidongDai,et al."High and highly anisotropic electrical conductivity of the asthenosphere due to hydrogen diffusion in olivine".Earth and Planetary Science Letters 408.1(2014):79-86.

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