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The continental crust and the oceanic crust.
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.
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.
source: http://library.thinkquest.org/C003124/en/crust.htm
What else can I help you with?
Is the Earth's surface mostly land?
No. Earth is mostly composed of the hydrosphere (water) with 3/4 of the earth's surface. While lithosphere has 1/4 of earth's surface.
What is the major agent of erosin on Earth' surface?
Water is the major agent of erosion on Earth's surface. It can wear away rock and soil through processes like rainfall, rivers, and waves. Water erosion shapes the landscape by carrying sediment and reshaping landforms over time.
How many tectonic plates make up Earth's surface?
There are about 7 major tectonic plates that make up Earth's surface, including the Pacific Plate, North American Plate, Eurasian Plate, African Plate, Antarctic Plate, Indo-Australian Plate, and South American Plate.
What are major pathways by which energy is absorbed by earth surface?
The major pathways by which energy is absorbed by Earth's surface are through direct sunlight (solar radiation), infrared radiation from the atmosphere, and heat transfer from the Earth's interior. Solar radiation is the primary source of energy for the planet and drives many of Earth's processes, such as photosynthesis and weather patterns.
What percentage of earth is made of soil?
Approximately 25% of Earth's surface is covered by soil.
What is the major agent of Earth's surface?
The major agent of erosion on earthes surface is water running downhill
What is a major agent of change on earth's surface?
monica
Major cause of shaping the surface of earth?
water
What part of the earth's surface is water?
3/4 of the earth's surface is water.
How much of Earth's surface is covered by one desert land?
There is no single desert that covers the earth. There are about 28 major deserts that, combined, cover about 1/3 of the earth's land area.
How many major plates are on the earth's surface?
twelve (12)
Name of major mountains in the Virgin Islands?
it is like the earth surface is rising and the earth is draining
What are the aid of major feature of the earth surface?
partly land and water
What major force shapes Earth's surface?
runnig water, and wind :)
How much of earth's land surface is desert?
About 33% of the earth's land surface is covered by deserts. That's 1/3 of the surface.
What percent of the Earth's surface does the Arctic Ocean cover?
The Arctic Ocean covers roughly 9% of the Earth's surface.
How much does the oceans cover the earth surface in fraction?
3/4 of earth's surface is covered by water bodies. Earth's surface mainly contain water.
