Understanding mantle heterogeneities and their effects on mantle evolution through the lens of mineral physics

Abstract:

Although the canonical view of mantle convection typically suggests a mantle that is well mixed and homogeneous over geological time scales, seismic tomography and petrology suggest otherwise. From an experimental mineral physics perspective, I’ll explore some ways that this is possible. These possibilities include—but are not limited to: regionally varying bulk compositions and redox state, the spin transition of iron, and partial melting in important mantle minerals. Each of these influence not only the density of the mantle rocks, thereby influencing their buoyancy and ability to convect and be sampled, but also how quickly seismic waves travel through them.

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.