There are two types of lithosphere—oceanic and continental. As with oceanic crust, continental crust is created by plate tectonics. The African Plate is a major tectonic plate straddling the equator as well as the prime meridian.It includes much of the continent of Africa, as well as oceanic crust which lies between the continent and various surrounding ocean ridges.Between and , the Somali Plate began rifting from the African Plate along the East African Rift. However, crustal heterogeneity has prevented a thorough geochemical comparison of … Figure 11.23 shows the major features of plate interactions. The continental crust is older than the oceanic crust… Plate tectonics is the scientific theory explaining the movement of the earth’s crust. The earth's crust is the thickest below the continents. Any continetnal material that is towed by the oceanic crust collides with the overriding continental crust. Tectonic plates actually slide around on the mantle, causing earthquakes, mountain formation, continental drift, volcanoes, and other geologic activity on the crust. The continental crust is central to the biological and geological history of Earth. Tectonic setting is the principal controlling factor of lithology, chemistry, and preservation of sediment accumulations in their depocenters, the sedimentary basins. Continental lithosphere is too buoyant to subduct deeply, so rather than a subduction zone and trench these boundaries encompass a thick mess of folded, piled-up crust. In pink, we see oceanic crust that starts its journey at mid-ocean ridges and spreads out over millions of years to subduct under light blue continental shelves, taking carbon along for the ride. At convergent plate boundaries, where tectonic plates crash into each other, continental crust is thrust up in the process of orogeny, or mountain-building.For this reason, the thickest parts of continental crust are at the world’s tallest mountain ranges. 7.14). The denser plate, made of oceanic crust, is subducted underneath the less dense plate, which can be either continental or oceanic crust. The mantle, oceanic crust, and continental crust all have different compositions due to a process called partial melting. At convergent plate boundaries, oceanic crust is often forced down into the mantle where it begins to melt. Recall that both continental landmasses and the ocean floor are part of the earth’s crust, and that the crust is broken into individual pieces called tectonic plates (Fig. The process which creates new oceanic crust as magma rises towards the surface and solidifies at divergent boundaries; divergence of TWO oceanic plates. Oceanic lithosphere is thinner and denser (about 50 km, or 30 mi thick), whereas continental lithosphere is thicker and lighter (about 150 km, or 95 mi thick).

major tectonic features of the oceanic and continental crust