An international research group led by Dr. Takayuki Ishii from HPSTAR and Okayama University, Institute for Planetary Materials, in collaboration with colleagues from Bayerisches Geoinstitut, University of Bayreuth, Germany, and Japan Synchrotron Radiation Research Institute, Okayama University Institute for Planetary Materials and Tohoku University, Japan, Peking University and Yanshan University, China has precisely determined the temperature dependence of the high-pressure phase transition pressure of a mantle mineral of pyrope garnet to bridgmanite plus corundum (post-garnet transition) which may well explain the puzzling dynamics of subducting slabs and upwelling plumes observed seismically in the upper part of the lower mantle.
https://www.miragenews.com/curved-post-garnet-phase-boundary-solves-1056169/#miragenews