ENV200H1 Chapter Notes - Chapter 12: Oceanic Crust, Plate Tectonics, Outer Core
Document Summary
Chapter 12 environmental geology and earth resources. Earth is a dynamic planet and constantly changing structure (cid:173) Earth is a layered sphere: core = a dense, intensely hot mass of metal (e. g. , mostly iron) Generates a magnetic field: mantle = a hot, pliable layer of rock. Contains a high concentration of lighter elements (e. g. , oxygen, silicon, magnesium: crust = a cool, lightweight, brittle layer of rock. Crust under oceans is relatively thin, dense, and young because of constant recycling. Crust under continents is relatively thick, light, and old, with new material being added continually. Tectonic processes reshape continents and cause earthquakes (cid:173) Higher peaks, deeper canyons, and sheerer cliffs than any continental mountains. May explain the periodic mass extinctions of organisms between major geologic periods (cid:173) humans have now become a major geological force: we may cause more species extinction than any natural forces, anthropocene era = dominated by humans.
