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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 ...
North China Craton – Continental crustal block in northeast China, Inner Mongolia, the Yellow Sea, and North Korea; Ossa-Morena plate; Piemont-Liguria plate – Former piece of oceanic crust that is seen as part of the Tethys Ocean; Proto-Alps terrane; Rhenohercynian plate – Fold belt of west and central Europe, formed during the Hercynian ...
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 thin parts are the oceanic crust, which underlies the ocean basins (5–10 km) and is mafic-rich [9] (dense iron-magnesium silicate mineral or igneous rock). [10] The thicker crust is the continental crust, which is less dense [11] and is felsic-rich (igneous rocks rich in elements that form feldspar and quartz). [12]
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 ...
At a subduction zone the relatively cold, dense oceanic crust sinks down into the mantle, forming the downward convecting limb of a mantle cell, which is the strongest driver of plate motion. The relative importance and interaction of other proposed factors such as active convection, upwelling inside the mantle, and tidal drag of the Moon is ...
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).
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 ...