Exhumation of deeply subducted crust: Review and outlook

Abstract

The discovery of ultrahigh-pressure (UHP) index minerals such as coesite and micro-diamond in supracrustal rocks indicate that a large amount of crustal rocks were subducted to mantle depths and subsequently returned to the Earth’s surface. However, exhumation mechanism of the deeply subducted crustal rocks has been a hot topic in geodynamic community and remains controversial. Previous studies have been performed by petrologic observations, analogue experiments and numerical simulations for exhumation processes and mechanisms of deeply subducted crustal rocks, and a series of important results have been achieved. In this paper, we summerize in detail recent progresses and existing problems on types of subduction zones, exhumation processes and mechanisms of deeply subducted crustal rocks, and related factors. Based on these, three forthcoming prospects are presented: (1) The geological processes within the exhuming crust; (2) the interaction between the exhuming crust and the surface process; (3) the interaction between the exhuming crust and the mantle.