The composition of granulites in the post-Archean lower continental crust is reviewed and data from the chemical data base are compared with models of restite composition derived from experimental studies and trace element partitioning behavior. It is found that, although intracrustal melting is the means by which the granitic upper crust is formed, most granulite facies terranes are not mafic residues left after partial melting of intermediate rock types. Granulitic lower crustal xenoliths are mafic and have compositions suitable to mass balance the upper crust. However, most have either meltlike compositions or are crystal cumulates. This suggests that basaltic underplating plays a fundamental role in crustal growth and differentiation.