EES 1080 Lecture Notes - Lecture 7: Continental Drift, Continental Margin, Outer Core
31 Dec 2018
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Document Summary
Average thickness: 17 km (10mi: outer layer: 30-40 km at continents. Inner layer: 5-7 km under oceans: crust/mantle boundary, moho discontinuity, mantle, composed of ultramafic rocks, core, outer core: liquid core of iron and nickel alloy, average density: 11. 0 g/cm3. Inner core: solid core of iron and nickel alloy: average density: 13. 0 g/cm3. Lithosphere: crust and uppermost mantle: behaves rigidly, asthenosphere: upper mantle, behaves plastically. Continents: shield, exposed, buried, old mountain roots, active mountain building. Oceans: continental margin, ocean basin, mid-ocean ridges. Plate boundaries (figure 2. 1: plate types, continental, oceanic, plate movement, collide, separate, slide past each other. Collision of plates: continental (thick) oceanic (thin, subduction- oceanic (thin) plate will be pushed down under the continental (thick, oceanic and oceanic. Island arcs (islands: continental and continental, active mountain building. Separation of plates: occurs often in oceans, seafloor spreading, creates mid-ocean ridges, ex. mid atlantic ridge (mantle rocks rises to fill gap)
