Volume 3 examines the chemical composition of the Earth's crust, starting with the continental crust and the rocks exposed therein, moving on to oceanic crust (MORB and oceanic plateaus) and finishing with island arc crust. In addition to providing a descriptive geochemistry of the Earth's crust, the volume summarizes the processes responsible for crustal formation and modification, exchange between the crust and other Earth reservoirs (mantle, oceans and atmosphere), and examines the secular evolution of the crust. Reprinted individual volume from the acclaimed Treatise on Geochemistry, (10 Volume Set, ISBN 0-08-043751-6, published in 2003)