Single-crystal elasticity of iron-bearing phase E and seismic detection of water in Earth's upper mantle

被引：9

作者：

Satta, Niccolo ^{[1
]}

Marquardt, Hauke ^{[2
]}

Kurnosov, Alexander ^{[1
]}

Buchen, Johannes ^{[3
]}

Kawazoe, Takaaki ^{[4
]}

McCammon, Catherine ^{[1
]}

Ballaran, Tiziana Boffa ^{[1
]}

机构：

[1] Univ Bayreuth, Bayer Geoinst, D-95440 Bayreuth, Germany

[2] Univ Oxford, Dept Earth Sci, Oxford OX1 3AN, England

[3] CALTECH, Seismol Lab, Pasadena, CA 91125 USA

[4] Hiroshima Univ, Dept Earth & Planetary Syst Sci, Hiroshima 7398526, Japan

来源：

AMERICAN MINERALOGIST | 2019年 / 104卷 / 10期

关键词：

DHMS; phase E; Brillouin spectroscopy; elasticity; HYDROUS MAGNESIUM SILICATES; EQUATION-OF-STATE; HIGH-PRESSURE; BRILLOUIN-SCATTERING; STABILITY; SLABS; WADSLEYITE; TRANSPORT; HYDRATION; ANOMALIES;

D O I：

10.2138/am-2019-7084

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

The elastic properties of Mg2.12(2)Fe0.21(2)Ni0.01Si1.15(1)O6H2.67(8) phase E single crystals with Fe3+/Sigma Fe = 0.25(3) have been determined by Brillouin spectroscopy at ambient conditions. We find that that the elasticity of iron-bearing phase E is described by the six independent stiffness tensor components (all in units of GPa): C-11 = 192.2(6), C-12 = 56.4(8), C-13 = 43.5(8), C-14 = -4.3(3), C-33 = 192.1(7), C-44 = 46.4(3). The Voigt-Reuss-Hill averages of bulk and shear moduli are 95.9(4) and 59.6(2) GPa, respectively. The aggregate velocities of iron-bearing phase E are v(P) = 7.60(2) and v(S) = 4.43(1) km/s, markedly lower than those of major mantle minerals at ambient conditions. Modeling based on our results suggests that the presence of iron-bearing phase E may reduce the sound wave velocities in upper mantle and transition zone rocks, making it a possible target for future seismological investigations aiming to map hydration in subducting slabs.

引用

页码：1526 / 1529

页数：4