Hp-Uhp Metamorphism And Tectonic Evolution Of Orogenic Belts: Introduction

High pressure (HP) and ultrahigh pressure (UHP) metamorphic rocks play a key role for understanding the tectonic evolution of orogenic belts (Johnson, M. R. W. & Harley, S. L. 2012. Orogenesis: The Making of Mountains. Cambridge University Press, Cambridge). They have typically experienced complex changes during subduction and exhumation processes, arising from recrystallization, deformation, element redistribution, fluid-rock interactions and even partial melting, and may therefore carry a valuable record of evolving geodynamic systems in an orogenic belt. Until now, more than 20 UHP metamorphic belts, i.e. belts which contain rocks that experienced pressure-temperature (P-T) conditions exceeding the lower limit of the coesite stability field, have been identified all over the world (Carswell, D. A. & Compagnoni, R. 2003. Ultrahigh Pressure Metamorphism. Eotvos University Press, European Mineralogical Union, Notes in Mineralogy, Budapest; Liou, J. G., Ernst, W. G., Zhang, R. Y., Tsujimori, T. & Jahn, B. M. 2009. Ultrahigh-pressure minerals and metamorphic terranes-the view from China. Journal of Asian Earth Sciences, 35, 199-231; Zheng, Y. F., Zhang, L. F., McClelland, W. C. & Cuthbert, S. 2012. Processes in continental collision zones: preface. Lithos, 136, 1-9). New and innovative studies from different geoscience disciplines have been invaluable in developing a better understanding of the geodynamic evolution of orogenic belts. This special issue contains 15 papers, most of which were presented as part of the session 'HP-UHP metamorphism and tectonic evolution of orogenic belts', held at the 35th International Geological Congress in Cape Town, South Africa during 27 August to 4 September, 2016.