8吉帕斯卡压力、800开尔文温度下硅酸镁钙钛矿的超声剪切波速度与下地幔成分

Ultrasonic shear wave velocities of MgSiO3 perovskite at 8 GPa and 800 K and lower mantle composition.

作者信息

Sinelnikov YD, Chen G, Neuville DR, Vaughan MT, Liebermann RC

机构信息

Y. D. Sinelnikov and R. C. Liebermann, Center for High Pressure Research and Department of Geosciences, State University of New York at Stony Brook, Stony Brook, NY 11794-2100, USA. G. Chen and M. T. Vaughan, Center for High Pressure Research and.

出版信息

Science. 1998 Jul 31;281(5377):677-9. doi: 10.1126/science.281.5377.677.

DOI:10.1126/science.281.5377.677

PMID:9685256

Abstract

Ultrasonic interferometric measurements of the shear elastic properties of MgSiO3 perovskite were conducted on three polycrystalline specimens at conditions up to pressures of 8 gigapascals and temperatures of 800 kelvin. The acoustic measurements produced the pressure (P) and temperature (T) derivatives of the shear modulus (G), namely ( partial differentialG/ partial differentialP)T = 1.8 +/- 0.4 and ( partial differentialG/ partial differentialT)P = -2.9 +/- 0.3 x 10(-2) gigapascals per kelvin. Combining these derivatives with the derivatives that were measured for the bulk modulus and thermal expansion of MgSiO3 perovskite provided data that suggest lower mantle compositions between pyrolite and C1 carbonaceous chondrite and a lower mantle potential temperature of 1500 +/- 200 kelvin.

摘要

在高达8吉帕斯卡的压力和800开尔文的温度条件下，对三个多晶样品进行了MgSiO₃钙钛矿剪切弹性性质的超声干涉测量。声学测量得出了剪切模量（G）的压力（P）和温度（T）导数，即(∂G/∂P)T = 1.8 ± 0.4和(∂G/∂T)P = -2.9 ± 0.3×10⁻²吉帕斯卡每开尔文。将这些导数与测量得到的MgSiO₃钙钛矿的体积模量和热膨胀导数相结合，得到的数据表明下地幔成分介于橄榄岩和C1碳质球粒陨石之间，下地幔潜在温度为1500 ± 200开尔文。