Abstract
During the last two decades, studies of mineral transformations in high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic terranes have been an active discipline of the geosciences. Besides the advancement of knowledge within these fields, the research has played an important interdisciplinary role in linking processes such as continental collisions, deep subduction, exhumation, geochemical recycling from surface to the core, and the deep storage of light elements participating in greenhouse effects in the atmosphere.
Mineral reactions, their structural transformations, solid state flow, rock melting and interactions with fluids are some of the most important indicators of processes operating in deep subduction channels, where subducted lithospheric plates geochemically interact with the mantle wedge. Although deep subduction of continental materials to the upper mantle and mantle transition zone is no longer regarded as an enigma, fundamental questions still exist as to how continental material ultimately remixes into the mantle, and what mineralogical, petrological, geochemical and rheological parameters are responsible for such processes.