chap 11-19 - Chapter 11 Definitions: Inner Core- is a solid...

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Chapter 11 Definitions: Inner Core- is a solid iron which is surrounded by the outer core Outer core- dense, molten, fluid metallic-iron core, which surrounds the inner core. Inner mantle- Outer mantle Asthenosphere- The region of the upper mantle just below the lithosphere; the least rigid portion of Earths interior and known as the plastic layer, flowing very slowly under extreme heat and pressure. Continental crust- Oceanic crust Granite-a coarse-grained (slow cooling) intrusive igneous rock of 25% quartz and more than 50% potassium and sodium feldspars; characterized as the continental crust. Basalt-a common extrusive ingenious rock, fine-grained, comprising the bulk of the ocean-floor crust, lava flow, and volcanic forms; gabbro is its intrusive form. Isostasy- a state of equilibrium in the earths crust formed by the interplay between portions of the lithosphere and the asthenosphere and the principle of buoyancy. The crust depresses under weight and recovers with its removal, for example, the melting of glacier ice. The uplift is known as isostatic rebound. Geomagnetic reversal- a polarity change in earths magnetic field. With uneven regularity, the magnetic field fades to zero, then returns to full strength but with the magnetic poles reversed. Reversals have been recorded 9 times the past 4 million years. Geologic cycle- a general term characterizing the vast cycling that proceeds in the lithosphere. It encompasses the hydrologic cycle, tectonic cycle, and rock cycle. Rock cycle- a model representing the interrelationships among the three rock-forming processes: igneous, sedimentary, and metamorphic; shows how each can be transformed into another rock type. Rock- an assemblage of minerals bound together, or sometimes a mass of a single mineral. Mineral- an element or combination of elements that forms an inorganic natural compound; described by a specific formula and crystal structure. Igneous rock- One of the basic rock types; it has solidified and crystallized from a hot molten state (either lava or magma). Sedimentary rock- one of three basic rock types; formed from the compactions, cementation, and hardening of sediments derived from other rocks Metamorphic rock- one of three basic rock types, it is existing igneous and sedimentary rock that has undergone profound physical and chemical changes under increased pressure and temperature. Constituent mineral structures may exhibit foliated or non-foliated textures. Magma- molten rock from beneath earths surface; fluid, gaseous, under extreme pressure, and either intruded into existing country rock or extruded onto the surface as lava. Lava- magma that issues from volcanic activity onto the surface; the extrusive rock that results when magma solidified.
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Intrusive- having been forced between preexisting rocks or rock layers while in a molten or plastic condition . Of or relating to igneous rock that is forced while molten into cracks or between other layers of rock. Extrusive-
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This note was uploaded on 03/30/2008 for the course GEOG 203 taught by Professor Guneralph during the Spring '08 term at Texas A&M.

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chap 11-19 - Chapter 11 Definitions: Inner Core- is a solid...

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