Fluid activity during exhumation of deep-subducted continental plate

It is well known that a great deal of fluid wasreleased during subduction of oceanic crust, resulting in arcmagmatism, quartz veining and metamorphic mineralizationof syn-subduction. In contrast, the process of continentalsubduction is characterized by the relative lack of fluid andthus no arc magmatism has been found so far. During exhu-mation of deep-subducted continental crust, nevertheless,significant amounts of aqueous fluid became available fromthe decomposition of hydrous minerals, the decrepitation ofprimary fluid inclusions, and the exsolution of structuralhydroxyls. This kind of metamorphic fluid has recently at-tracted widespread interests and thus been one of the mostimportant targets in deciphering the geological processesconcerning metamorphism, magmatism and mineralizationin collisional orogens. A large number of studies inlvolvingstable isotopes, fluid inclusions and petrological phase rela-tionships have been accomplished in past a few years withrespect to the mobility and amount of met