Seismic observations indicate the presence of seismic anisotropy in several regions of the Earth’s upper and lower mantle. Seismic anisotropy is most likely caused by either crystallographic or shape preferred orientations of mantle phases, which in turn are caused by dynamic mass transport processes. The combination of laboratory constraints and seismic observations are, therefore, a promising avenue to unravel the dynamics of the deep Earth.
Deformation and Microtextures development in lower mantle materials
We are producing microstructures and crystallographic preferred orientation (CPO) in binary mixtures of perovskite and ferropericlase at relevant conditions of the lower mantle in a heated diamond-anvil cell. In-situ characterization using both axial and radial synchrotron x-ray diffraction in combination with ex-situ electron microscopy analyses allows for understanding the stress/strain-behavior in a typical lower mantle assemblage and its implications for seismic anisotropy observations and transport properties in the lower mantle.
Dr. Sergio Speziale
Dr. Hans Josef Reichmann
Dr. Hanns-Peter Liermann, Deutsches Elektronen-Synchrotron (DESY) Hamburg
Prof. Lowell M. Miyagi, Montana State University