Published by the American Geophysical Union as part of theGeophysical Monograph Series, Volume 174.
Discovery of the perovskite to post-perovskite phase transition inMgSiO3, expected to occur for deep mantle conditions,was first announced in April 2004. This immediately stimulatednumerous studies in experimental and theoretical mineral physics,seismology, and geodynamics evaluating the implications of a majorlower mantle phase change. A resulting revolution in ourunderstanding of the D" region in the lowermost mantle iswell underway. This monograph presents the multidisciplinaryadvances to date ensuing from interpreting deep mantleseismological structures and dynamical processes in the context ofthe experimentally and theoretically determined properties of thepost-perovskite phase change; the last silicate phase change likelyto occur with increasing pressure in lowermost mantle rocks.