The ‘new global tectonics’ or theory of ‘plate tectonics’ has its background in the observations made on the oceanic areas. It claims to extend the same principles to the continents as well. At first glance this attitude seems to be sound because the oceans occupy two thirds of the surface of the earth. But comparing the known age of the oldest rocks on the oceanic floor (150 m.y.) with the age of the oldest rocks on the continents (3500 m.y.), we realize that the discovery of general trends and laws of development of the crust through long geological time is possible primarily on the basis of continental geology. But certainly we should also take into account what is known about oceans.