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Thin oceanic crust is denser than the thicker continental crust and therefore 'floats' lower in the mantle as compared to continental crust. You will find some of the thinnest oceanic crust along mid ocean ridges where new crust is actively being formed.Jan 16, 2016

oceanic crust is thinner than continental crust as oceanic crust keeps regenerating. it forms at the oceanic ridges or other sources (divergent plate boundaries) and with time it spreads away from the place of origin and becomes thinner away from the place of origin.Jul 2, 2018

Oceanic crust is thinner and denser than continental crust. Oceanic crust is more mafic, continental crust is more felsic.

• A cross section of Earth's outer layers, from the crust through the lower mantle. Oceanic crust is about 6 km (4 miles) thick. It is composed of several layers, not including the overlying sediment.

• Oceanic crust is the crust layer found beneath the oceans and contains denser rock than the continental crust. Basalt is magma that builds up in time and gets broken down through the process of subduction. As this partial melting process occurs at the mid-ocean ridges, the oceanic crust increases in density.

• 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 is currently occupied by continental crust.

• Oceanic crust is the part of Earth's lithosphere that is under the ocean basins. Oceanic crust is primarily composed of mafic rocks, or sima which is named for its magnesium silicate mineral s. It is thinner than continental crust, and is about 7-10 kilometers thick, however it is more dense, having a mean density of about 3.3 g / cm 3.

Life cycle. Hence most oceanic crust is the same thickness (7±1 km). Very slow spreading ridges (<1 cm·yr −1 half-rate) produce thinner crust (4–5 km thick) as the mantle has a chance to cool on upwelling and so it crosses the solidus and melts at lesser depth, thereby producing less melt and thinner crust.

Oceanic crust is significantly simpler than continental crust and generally can be divided in three layers. According to mineral physics experiments, at lower mantle pressures, oceanic crust becomes denser than the surrounding mantle.

The oceanic crust covers about 60% (v/v) of the surface of the Earth and is relatively thin and geologically young, being less than 12 miles thick and younger than approximately 180 million years—older rocks have disappeared under the oceanic crust by subduction.

An example of this is the Gakkel Ridge under the Arctic Ocean. Thicker than average crust is found above plumes as the mantle is hotter and hence it crosses the solidus and melts at a greater depth, creating more melt and a thicker crust. An example of this is Iceland which has crust of thickness ~20 km.