block

shields, provinces, or blocks. Some examples include: the North Atlantic craton that incorporates northwestern Scotland, central Greenland, and Labrador; the Kaapvaal and Zimbabwean cratons in southern Africa; the Dharwar craton in India

…the subsequent dropping of a block of crust into the space created by the divergence of large crustal blocks or lithospheric plates. The extension of the brittle crust causes it to fracture, and as the adjoining crustal blocks or plates move apart, a smaller block slides down into the resulting…

…or subsidence of rock material—blocks, layers, or slices of the Earth’s crust, molten lavas, and even large masses that include the entire crust and uppermost part of the planet’s mantle. In some areas, these processes create and maintain high elevations such as mountains and plateaus. In others, they produce…