Learn about The Geology of the Earth in this educational video from dizzo95.
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Male Speaker: Since the advent of space exploration we have gained a new perspective of a globe we call the earth. Photographs from space show a view of earth floating in the heavens, white clods swirling above the oceans and continents. Within the spheres contained a series of concentric layers at the center is a solid core surrounded by a dense bubbling mass of super heated molten rock, we live on the surface of fragile shifting crust in places barely three miles thick the earth surface is constantly moving at one time some 200 million years ago it was only one vast continent on the earth hungaya over millions of years the land mass is moved and separated and continue to do so today, about a 135 million years ago South America began to drift away from Africa. Here its crust consist of rigid plates which are continually shifting position the plates are moved by conviction currents the molten layer beneath the surface. As the plate separate usually allowing the thinner oceanic trenches molten lava rises from beneath the surface and moves into the gap that is created, the new rock helps push the plates apart and as it cools becomes part of the continually regenerating crust. And the other sides of the plate different types of collisions occur with other moving plates as the ocean plates meet contental plate's they are forced downward. Beneath the surface friction and pressure force molten rock upward to erupt through the crust as ash and lava. Volcanoes have been formed in this way strong along the western edge to the North and South American continent. The second type of collision occurs is two continental plates converge as one plate slides under the other, the lighter mass of the surface thrusts and force upward forming some of the worlds high mountain chains. The third type of plate interaction occurs were plates meet at oblique angles to each other pressure and friction between the surfaces prevent slippage when the tension becomes too great the plate shift sliding along a -- occasionally violent trimmers result and cause the wide spread destruction of a earthquake. The Alaskan earthquake if 1964 was caused by such a shift in the fault running alone the western edge of North America. The earths landscapes have been created over millennium or the gradual shifting contental plates and by the violent effects of volcano's and earthquakes. These primitive shapes are in turn worked upon by other natural forces, Thrust cracks the mountain rocks, glacial ice, wind and water transport rubble into the low lands. Rivers edge the valleys carrying small stones to perceive were layer upon layer sand and organic matter is pressed to ocean floor. These sedimentary layers are changed over time by pressure and heat from deep within the earth there are many different types of sedimentary transformed into a vast range of rocks minerals and ores agitation becomes the energy with the coal, oil and natural gas. Rock sediment becomes the hard metamorphic rock that gives us valuable ores and the building materials, we praise for their strength and decorative features. The most valued of all the rocks, the gems and semi precious stones mined from the earth are exposed to the surface by wind and water the most priced them all is the diamond as the occurrence of the molten rock force upwards and build the rocks that release these precious stones so to that they force the older layers and sediment downward. Eventually this sinking rock contacts the enormous heat inside the earth melts and returns once again to the cycle of eruption and component movement that gives form a planet we live on.