- published: 28 Mar 2016
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The continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the 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 more felsic, or granitic, in contrast to the oceanic crust, called sima, whose bulk composition is more mafic or basaltic rock. (Based on the change in velocity of seismic waves, it is thought that at a certain depth sial becomes to sima close in its physical properties. This line is called the Conrad discontinuity.)
Consisting mostly of granitic rock, continental crust has a density of about 2.7 g/cm3 and is less dense than the material of Earth's mantle, which consists of ultramafic rock and whose density is about 3.3 g/cm3. Continental crust is also less dense than oceanic crust, whose density is about 2.9 g/cm3. Continental crust is considerably thicker than oceanic crust, mostly 25 to 70 km versus the average thickness of the oceanic crust of around 7–10 km. About 40% of Earth's surface is now overlaid by continental crust. Continental crust makes up about 70% of the volume of Earth's crust.
continental crust
The "continental crust" is the layer of igneous, sedimentary, and metamorphic rocks which forms the continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called "sial" because there is more felsic, or granitic, bulk composition, which lies in contrast to the oceanic crust, called "sima" because of the mafic or basaltic rock. Consisting mostly of granitic rock, continental crust has a density of about 2.7 g/cm 3 and is less dense than the material of the Earth's mantle , which consists of ultramafic rock. Continental crust is also less dense than oceanic crust , though it is considerably thicker; mostly 25 to 70 km versus the average oceanic thickness of around 7–10 km. About 40% of the Earth's surface is now overlaid b...
The continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the 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 more felsic, or granitic, in contrast to the oceanic crust, called sima, whose bulk composition is more mafic or basaltic rock. Consisting mostly of granitic rock, continental crust has a density of about 2.7 g/cm3 and is less dense than the material of Earth's mantle, which consists of ultramafic rock and whose density is about 3.3 g/cm3. Continental crust is also less dense than oceanic crust, whose density is about 2.9 g/cm3. Continental crust is considerably thicker than oceanic crust, mostly 25 to 70 km versus the average thickn...
A brief description on the continental crust.
The recipient of the 2012 Wollaston Medal, Chris Hawkesworth, delivers a talk on 'The generation and destruction of continental crust'
These four middle-schoolers are doing a performance on continental crust movements. As you can see, for the convergent boundary, Nadia and Fynnola are plates converging and they soon form into a mountain range. In the divergent boundary, Nadia and Fynnola are 1 plate and Gabriel and Gard are another plate. They are diverging and form a mid-ocean ridge by having two "wheel barrows". And finally, In the transform boundary, once again, Nadia and Fynnola are 1 plate and Gabriel and Gard are another plate. A transform boundary forms an earthquake and as Nadia and Gabriel come into contact, all of them shake as though it's an earthquake. And this concludes Nadia, Fynnola, Gabriel and Gard's performance on continental crust movements =]