HP–UHP metamorphism and tectonic evolution of orogenic belts: introduction

Abstract

Abstract 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.