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The thickness of Earth's crust (km). The continental crust consists of various layers, with a bulk composition that is intermediate (SiO 2 wt% = 60.6). [5] The average density of the continental crust is about, 2.83 g/cm 3 (0.102 lb/cu in), [6] less dense than the ultramafic material that makes up the mantle, which has a density of around 3.3 g/cm 3 (0.12 lb/cu in).
The estimated average density of the continental crust is 2.835 g/cm 3, with density increasing with depth from an average of 2.66 g/cm 3 in the uppermost crust to 3.1 g/cm 3 at the base of the crust. [13] In contrast to the continental crust, the oceanic crust is composed predominantly of pillow lava and sheeted dikes with the composition of ...
continental crust The layer of granitic, sedimentary, and metamorphic rocks which form the parts of the Earth's crust that comprise the continents, and the areas of shallow seabed close to their shores (known as continental shelves). continental margin Zone of the ocean floor, separating the thin oceanic crust from thicker continental crust.
The internal structure of Earth. In geology, the crust is the outermost solid shell of a planet, dwarf planet, or natural satellite.It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be defined based on its phase (solid crust vs. liquid mantle).
Most areas of oceanic crust show characteristic stripes due to periodic magnetic reversals during formation at a mid-oceanic ridge. The continental crust is by contrast typically magnetically quiet. This method is dependent on stripes being present and will not work for oceanic crust created during the Cretaceous Quiet Zone. On some magma-rich ...
In geology, a continent is defined by continental crust, which is a platform of metamorphic and igneous rocks, largely of granitic composition. Continental crust is less dense and much thicker than oceanic crust, which causes it to "float" higher than oceanic crust on the dense underlying mantle. This explains why the continents form high ...
The continental crust is composed primarily of sedimentary rocks resting on a crystalline basement formed of a great variety of metamorphic and igneous rocks, including granulite and granite. Oceanic crust is composed primarily of basalt and gabbro. Both continental and oceanic crust rest on peridotite of the mantle. [citation needed]
The basement rocks of the continental crust tend to be much older than the oceanic crust. [3] The oceanic crust can be from 0–340 million years in age, with an average age of 64 million years. [4] Continental crust is older because continental crust is light and thick enough so it is not subducted, while oceanic crust is periodically ...