= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
In the basic sense, dirt, rock, and molten lava.
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
2006-09-16 08:22:09
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answer #1
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answered by Anonymous
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The crust covers the mantle and is the earth's hard outer shell, the surface on which we are living. Compared to the other layers the crust is much thinner. It floats upon the softer, denser mantle. The crust is made up of solid material but this material is not the same everywhere. There is an Oceanic crust and a Continental crust. The first one is about 4-7 miles (6-11 km) thick and mainly consists of heavy rocks, like basalt. The Continental crust is thicker than the Oceanic crust, about 19 miles(30 km) thick. It is mainly made up of light material like granite.
Oceanic crust:
As the name already suggests, this crust is below the oceans. There, the crust is 4-7 miles (6-11 km) thick. The rocks of the oceanic crust are very young compared with the rocks of the continental crust. The rocks of the oceanic crust are not older than 200 million years. The material of which the oceanic crust consists is for the greater part tholeiitic basalt (this is basalt without olivine). Basalt has a dark, fine and gritty volcanic structure. It is formed out of very liquid lava, which cools off quickly. The grains are so small that they are only visible under a microscope. The average density of the oceanic crust is 3g/cm³.
Continental crust:
When you look at the globe, you see that the surface of the earth consists of a lot of water (71%). The other 29% consists of land. You can divide this land into six big pieces, which are called continents. The different continents - arranged in decreasing order of size - are: Eurasia (Europe and Asia together), Africa, North-America, South-America, Antarctica and Australia. In the past the division of the continents was different (see plate tectonic). The earth's crust is the thickest below the continents, with an average of about 20 to 25 miles (30 to 40 km) and with a maximum of 45 miles (70 km). The continental crust is older than the oceanic crust, some rocks are 3.8 billion years old. The continental crust mainly consists of igneous rocks and is divided into two layers. The upper part mainly consists of granite rocks, while the lower part consists of basalt and diorite. Granite is lightly-colored, coarse-grain, magma. Diorite has the same composition, but it's scarcer than granite and is probably formed by impurities in the granite-magma. The average density of the continental crust is 2.7g/cm³.
2006-09-16 08:27:02
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answer #2
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answered by Anonymous
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Crust is made with Crisco (the shortening, not that liquid stuff), salt, and cold water.
2006-09-16 08:22:00
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answer #3
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answered by Carlos R 5
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pizza crust
2006-09-16 08:18:13
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answer #4
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answered by Anonymous
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bread, its all really a bread crust.
2006-09-16 08:19:14
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answer #5
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answered by Anonymous
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Dirt piled on more dirt and rocks.
2006-09-16 08:23:39
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answer #6
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answered by Picture Taker 7
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All kinds of stuff, rocks, dirt, dead things, etc
2006-09-16 08:24:32
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answer #7
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answered by ReelGenius 2
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Hope this helps.
http://mediatheek.thinkquest.nl/~ll125/en/crust.htm
2006-09-16 08:26:02
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answer #8
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answered by whtecloud 5
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bread crumbs
2006-09-16 08:18:55
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answer #9
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answered by Anonymous
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