Rock density study

Density of volcano-sedimentary complexes progressively rises going down the Paleozoic section and decreases in the Precambrian. Density of the intrusive rocks is determined largely by their composition. There seem to be lateral changes in rock density, correlative with surface relief of the crust, differences in intensity of metamorphism, and intensity of dislocation. The density differences may be related to those in the degree of weathering or in the conditions, nature and intensity of metamorphism. --Author.