瓦兹利石（β-Mg2SiO4）在7吉帕斯卡压力和873开尔文温度下的弹性模量。

Elastic moduli of wadsleyite (beta-Mg2SiO4) to 7 gigapascals and 873 kelvin.

作者信息

Li B, Liebermann RC, Weidner DJ

机构信息

B. Li, Center for High Pressure Research and Mineral Physics Institute, State University of New York, Stony Brook, NY 11794-2100, USA. R. C. Liebermann and D. J. Weidner, Center for High Pressure Research and Department of Geosciences, State.

出版信息

Science. 1998 Jul 31;281(5377):675-7. doi: 10.1126/science.281.5377.675.

DOI:10.1126/science.281.5377.675

PMID:9685255

Abstract

Simultaneous sound velocity measurements and x-ray diffraction studies were made on wadsleyite (beta-Mg2SiO4) to 7 gigapascals and 873 kelvin. The calculated adiabatic bulk (K) and shear (G) moduli yield K (at room conditions) = 172(2) gigapascals, dK/dP = 4.2(1), and dK/dT = -0.012(1) gigapascals per kelvin, and G (at room conditions) = 113(1) gigapascals, dG/dP = 1.5(1), and dG/dT = -0. 017(1) gigapascals per kelvin, respectively. The data imply that the P and S wave velocity contrasts between olivine and wadsleyite require an olivine amount of 38 to 39 percent in the upper mantle to satisfy the observed 410-kilometer discontinuity, but 55 to 60 percent to account for the velocity increase through the transition zone.

摘要

对瓦兹利石（β-Mg2SiO4）在7吉帕斯卡压力和873开尔文温度下同时进行了声速测量和X射线衍射研究。计算得到的绝热体积模量（K）和剪切模量（G）结果为：K（在室温条件下）= 172(2)吉帕斯卡，dK/dP = 4.2(1)，dK/dT = -0.012(1)吉帕斯卡每开尔文；G（在室温条件下）= 113(1)吉帕斯卡，dG/dP = 1.5(1)，dG/dT = -0.017(1)吉帕斯卡每开尔文。这些数据表明，橄榄石和瓦兹利石之间的P波和S波速度差异意味着，上地幔中橄榄石的含量需为38%至39%才能满足观测到的410千米不连续面，但要解释穿过过渡带的速度增加则需要55%至60%的橄榄石含量。