SE24
Continental collision,ultrahigh-pressure metamorphism and crustal recycling

Main Organiser
Yong-Fei Zheng
University of Science and Technology of China
School of Earth and Space Sciences
yfzheng@ustc.edu.cn

Co-Organiser(s)
J.G.Liou
Stanford University
liou@pangea.stanford.edu

Jinghui Guo
Institute of Geology and Geophysics
jhguo@mail.igcas.ac.cn

Brief Description
Geological processes at subduction zones are important for understanding a wide spectrum of phenomena including ultrahigh-pressure metamorphism, syn- and post-magmatism and seismicity. They are also a key to understanding the evolution of the Earth, including global circulation of water, fate of the deep-subducted slab and the delaminated lower crust, origin of igneous rocks in collisional orogenic belts, and recycling of continental crusts. In particular, metamorphic devolatilization and anatexis of subducted sediments and hydrothermally-altered crust are vital to syn- and post-collisional magmatism. While fluids are well known to play key roles in chemical cycling during oceanic crust subduction, it is less known whether devolatilization and fluid mobility are also active during continental subduction and exhumation. Some major topics to be covered, but not limited to, are: the nature and geochemistry of subducted crusts, metamorphic phase equilibria, ultradeep minerals, timing of peak metamorphism, fluid activity during subduction and exhumation, and crustal anatexis and post-magmatism in subduction zones.