Post Garnet Phases and the Mineralogy of the Lower Mantle

抄録

Phase relations of garnet with variable compositions were studied using different types of high pressure apparatus and synchrotron radiation. The results of in situ X-ray observations and transmitting electron microscope (TEM) analysis of the recovered samples revealed that garnet first breakdown into an assemblage consisted of aluminous perovskite and other phase (s) under the lower mantle condition. The solubility of aluminum into the perovskite phase is likely to be enhanced by pressure and an existence of iron and calcium.