Orogenic and metamorphic processes in plate boundaries: Synopsis and future directions

Abstract

This paper contains a series of essays which form a synopsis of my research career, which has been dedicated to orogenic and metamorphic processes in plate boundaries. It also presents my future research directions and latest investigations into simplifying the complexity of metamorphic rocks, their ˆeld observations, and associated convergent plate margin dynamics. Slab dehydration beneath forearcs and arc has been one of the most exciting problems in the ˆeld of convergent plate margin dynamics in recent decades. Orogenic and metamorphic processes are closely related. In the subduction zones, the ‰uid  mediated processes primarily control the crust  to  mantle transfer of volatiles, redox states of the wedge mantle peridotite and arc magmas, ‰ux  melting to generate arc magmas, and seismicity. Although the methods of classical metamorphic petrology, based on phase equilibrium calculations, and the application of conventional geochronology continue to provide the opportunities to link high  pressure and ultra  high  pressure metamorphism to geophysical observations today, advances in geochemical techniques have great potential for key geological markers in global convergent margins. For example, recent analytical techniques and applications used in studies of metamorphic rocks, such as in  situ Li  B  Sr  Pb spot isotope analyses of jadeite, serpentinite, lawsonite, etc., evaluate hydration and dehydration along the subduction channels and subse-quent slab  mantle interaction, and visualize more realistic ancient Pacific  type convergent margins. The scientiˆc value of subduction  zone rocks and crustal rocks are not limited to their worth for geochemistry: Some metamorphic rocks and minerals are important for all realms of geological sciences, from nano  scale kinetics to the scale of mountain building events. Consequently, collaborative exchange among geoscientists, through the application of applying diŠerent approaches, tests, and challenges, to address problems related to plate boundaries in the future.