ASTA01H3 Lecture Notes - Lecture 1: Lithosphere, Subduction, Natural Resources Defense Council
Document Summary
The convection of mantle also gives rise to plate tectonics. The lithosphere is broken into a number of plates which oat on top of the mantle due to the convection of the mantle. Plate tectonics is the theory which describes the earth"s surface geology as a result of the slow motion of the plates. Tectonics refers to any building on the surface of a planet which reshapes the surface through stretching, compression, or other forces in uencing the lithosphere. The motion of the crustal plates brings about volcanism, earthquakes and mountain building. Two types of crustal plates: continental plates and oceanic plates. Continental plates are old and have a thickness of 20-70 kms while oceanic plates are young and have thickness of 5-10 kms. Oceanic plates are constantly recycled into the mantle by diving under continental plates and melting into the mantle.
