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Unformatted text preview: 1) Core a) Innermost zone. b) It is extremely hot and has a solid inner part, surrounded by a liquid core of molten or semisolid material 2) Mantle a) Thick zone that surrounds the core b) Solid rock, but under its rigid outermost part is a zone-the asthenosphere-of hot, partly melted pliable rock that flows and can be deformed like soft plastic. 3) Crust a) Outermost and thinnest zone of the earth is the crust. b) Continental crust i) Underlies continents c) Oceanic crust i) Underlies ocean basins and covers 71% of the earths surface 4) Moving tectonic plates a) Convection cells and currents move large volumes of rock and heat in loops within the mantle like giant conveyor belts b) Tectonic plates i) Various sized areas of the earths lithosphere that move slowly around with the mantles flowing asthenosphere. ii) Most earthquakes and volcanoes occur around the boundaries of these plates iii)Lithosphere (1) Outer shell of the earth, composed of crust and the rigid, outermost part of the mantle outside the asthenosphere (2) Material found in earths plates c) Types of boundary i) Convergent plate boundary (1) When internal forces push two plates together (2) Subduction (a) Continental plate usually rises up over the denser oceanic plate and pushes it down into the mantle (b) Subduction zone (i) Area where this collision takes place. (ii) Plate melts and eventually rises again to the surface as magma (c) Trench forms between converging plates ii) Divergent plate boundary (1) Area where the earths lithospheric plates move apart in opposite directions (2) Creates oceanic ridges that have higher peaks and deeper canyons than mountains found on earth iii) Transform fault (1) Plates slide and grind past one another along a fracture in the lithosphere iv) Earthquakes and volcanoes are likely to be found at plate boundaries 5) Wearing down and building up the earths surface a) Some processes wear down the earths surface by moving topsoil and pieces of rock from one place to another, while other processes build up soil on the earths surface b) Weathering i) Physical, chemical and biological processes that break down rocks and minerals into smaller particles that can help build soil...
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This note was uploaded on 09/08/2008 for the course GEOS 1024 taught by Professor Meschreiber during the Spring '08 term at Virginia Tech.
- Spring '08