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Paleoclimatology (thesaurus)

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continental crust  

Definition

  • Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called sial because its bulk composition is richer in aluminium silicates and has a lower density compared to the oceanic crust, called sima which is richer in magnesium silicate minerals and is denser. The average density of continental crust is about 2.83 g/cm3, less dense than the ultramafic material that makes up the mantle, which has a density of around 3.3 g/cm3. Continental crust is also less dense than oceanic crust, whose density is about 2.9 g/cm3. At 25 to 70 km, continental crust is considerably thicker than oceanic crust, which has an average thickness of around 7–10 km. About 40% of Earth's surface area and about 70% of the volume of Earth's crust is continental crust. Most continental crust is dry land above sea level. However, 94% of the Zealandia continental crust region is submerged beneath the Pacific Ocean, with New Zealand constituting 93% of the above-water portion. (Adapted from: https://en.wikipedia.org/wiki/Continental_crust)

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http://data.loterre.fr/ark:/67375/QX8-91FJ51J2-W

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