Plastic deformation of MgGeO3 post-perovskite at lower mantle pressures.
Polycrystalline MgGeO3 post-perovskite was plastically deformed in the diamond anvil cell between 104 and 130 gigapascals confining pressure and ambient temperature. In contrast with phenomenological considerations suggesting (010) as a slip plane, lattice planes near (100) became aligned perpendicular to the compression direction, suggesting that slip on (100) or (110) dominated plastic deformation. With the assumption that silicate post-perovskite behaves similarly at lower mantle conditions, a numerical model of seismic anisotropy in the D'' region implies a maximum contribution of post-perovskite to shear wave splitting of 3.7% with an oblique polarization.
Merkel
Sébastien
S
Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA. smerkel@berkeley.edu
Kubo
Atsushi
A
Miyagi
Lowell
L
Speziale
Sergio
S
Duffy
Thomas S
TS
Mao
Ho-Kwang
HK
Wenk
Hans-Rudolf
HR