Plastic deformation of rocks and mineral phases in the Earth’s interior plays a primary role in controlling large-scale dynamic processes such as mantle convection and associated plate tectonics. Volumetrically, the lower mantle is the largest region of the Earth, and thus great effort has been made to study the deformation behavior of the mineral phases that comprise the lower mantle. Plastic deformation of these rocks and mineral phases can also lead to preferred orientation development (texture), which, in turn, can result in anisotropic physical properties. Many regions of the Earth’s interior exhibit seismic anisotropy, and thus, considerable effort has been made to understand the processes leading to texture and anisotropy development in deep Earth phases. Studying deformation of lower mantle materials is technically challenging due to the extreme pressures and temperatures experienced by materials in the deep Earth. However, recent technological advances have allowed significant progress to be made toward understanding the deformation behavior of lower mantle phases. This chapter provides an overview of deformation mechanisms in lower mantle materials and the current state of experimental deformation studies on lower mantle mineral phases and polyphase aggregates of materials relevant to the lower mantle.
Miyagi, Lowell, Experimental Deformation of Lower Mantle Rocks and Minerals, Mantle Convection and Surface Expressions, Geophysical Monograph Series, Chapter 2, pp. 21-50. abstract