Create new lithosphere at MOR
Plate divergence causes mantle upwelling, which promotes mantle melting by reducing pressure
Melt migrates toward surface, & solidifies to form oceanic crust
Generates layered oceanic crust, with residual mantle at base, gabbroic layer = intrusive magma chambers, sheeted dike complex = feeders of extrusive material, & basaltic layer = extrusive carapace
Oceanic crust cooled by infiltrated sea water
Divergent plate boundaries are constructive plate boundaries