November 1, 2013
The significance of this work is “The modest strength of the lithosphere is a key to the operation of plate tectonics. However, previous experimental studies focused on a simple single phase material (olivine) and showed high strength of the lithosphere that is inconsistent with the operation of plate tectonics on Earth. In this work, a more realistic two-phase mixture (olivine + orthpyroxene) was used and showed that a minor phase, orthopyroxene, plays a major role to weaken the lithosphere. The deformation microstructures that were found in the samples are similar to those seen in actual shear zones.”