diastrophism

diastrophism

 or tectonism

Large-scale deformation of the Earth's crust by natural processes, which leads to the formation of continents and ocean basins, mountain systems and rift valleys, and other features by mechanisms such as lithospheric plate movement (see plate tectonics), volcanic loading, or folding. The study of diastrophism, or tectonic processes, is the central unifying principle in modern geology and geophysics.