Our main research area is the investigation of processes occurring during subduction, subsequent continental collision and associated mountain building. The mechanical, thermal and material transport consequences of such large scale processes are partially encoded in natural rocks in the form of distinct associations of mineral phases, their compositions and modal proportions, and microstructures. The subduction of oceanic and continental rocks is an important process for two large geochemical cycles on Earth. Firstly, fluids released by dehydration reactions in the subducted slab migrate upwards into the mantle wedge, into the overlying crust and may even become subsequently recycled into the atmosphere. Chemical components carried in these fluids are transported away from the down-going plate, may get sufficiently enriched to produce ore deposits, reach Earth’s surface by volcanic activity or get recycled into the oceanic crust via surface fluids and the oceans. Secondly, chemical components incorporated in refractory phases in the subducted plate are dragged down deep into the mantle or even the core-mantle boundary, where they contribute to re-enrichment of the deeper parts of the mantle. Quantifying these element fluxes in subduction and collision zones, as well as determining rates of the associated mineral growth and transformation (i.e. metamorphic) processes, is the major research focus of our group. Investigation of these processes that occur at inaccessible depths involves petrographical, petrological, geochemical, and geochronological studies of exhumed high and ultra-high pressure rocks as well as theoretical modeling of mineralogical processes along subduction-collision pressure-temperature trajectories.