Evidence of the existence of large-scale convection in the mantle from the top to the bottom of the mantle is the density of the material in the lower mantle according shock compression silicates. Calculations showed that under appropriate pressure and temperature distribution of the density in both parts of the mantle are well distributed density oceanic lherzolites - breeds raised in the transform faults of the ocean floor. This is evidence of the homogeneity of the chemical composition of the mantle at the same time is an indirect indication of the existence of large-scale convection in it, constantly stirring its substanceAnd this convection drives plate tectonics
