Relations between subduction, slab heating, slab dehydration and continental growth

The hydrated altered basalts of the oceanic crust, if subducted, could release large volumes of water during their phase transformations and partial melting reactions. If heat from shear strain recrystallizations largely heats the altered basaltic layer, only a 2 km thick layer could be heated significantly before the slab reaches 80–125 km depth. Most of the released waters should be driven into the deeper but cooler regions at the slab and andesitic-tonalitic partial melts should form in the heated altered basalt layer. Large volumes of water initially at the surface could be added to the mantle and tonalitic partial melts could be lost from the oceanic crust and added to the continental plate and could account for continental growth.