Figure 7.

Models have been developed to simulate emplacement of successive sills in the lower amphibolite crust [33,210,211]. The sills crystallize, and heat the surrounding crust, eventually generating melting. The mixed melts (residual melts from the basalts and partial melts of the crust) segregate by buoyant flow along grain boundaries. Over time, repeated injections of basalt leads to upward-migrating permanent melt lenses in the lower crust [211]. There are important implications of such a process: melts differentiate by reactive flow during upward percolation; and there is substantial assimilation of crustal melts.