Saturday, November 22, 2008

What are the parts of Earth's lithosphere?



The lithosphere (geosphere) is the "solid" part of Earth. It has two parts, the crust and the upper mantle.


The crust is Earth's outermost layer. The crust varies from 5 to 70 kilometers in thickness.


The crust includes rocks, minerals, and soil. There are two kinds of crust: continental and oceanic.


Yes, there is even crust under the ocean! The crust is constantly moving, which is why continents move and earthquakes happen. The science that studies how the parts of the crust move is called "Plate Tectonics.


"Earth's oceanic crust is a thin layer of dense rock about 5 kilometers thick. The continental crust is less dense,with lighter-colored rock, that varies from 30 to 70 kilometers thick. The continental crust is older and thicker than the oceanic crust.


The crust is made of many types of rocks and hundreds of minerals. These rocks and minerals are made from just 8 elements: Oxygen (46.6%), Silicon (27.72%), Aluminum (8.13%), Iron (5.00%), Calcium (3.63%), Sodium (2.83%), Potassium (2.70%), and Magnesium (2.09%). The oceanic crust has more Silicon, Oxygen, and Magnesium. The continental crust has more Silicon and Aluminum.


No comments: