Continents as the unique structures generated by the earth

The continents foundation of the lower basalt and upper granite-gneiss layers was formed in the Pre-Archean-Archean period. In Proterozoic and Fanerozoic on the edges of this foundation there appeared a cover of lower blocks and geosyncline-fold belts. On the other predominate part of the Earth surface (70 per cent of it) it was formed the primary crystal proto-crust of ultrabasic composition. It was only in Mesozoic that it lowered, was covered by the ocean water and the layer of young basalt. Consequently, continents are the planet active structures. They had formed on the large mantle fragments, appeared as a result of the explosion in the Proto-Earth.