What is the crust beneath the atlantic ocean like?

The oceanic crusts are thin and are usually about a thickness of about 5 to 7 km. They contain rocks that are poor in silica and mostly enriched in magnesium (Mg) and iron (Fe). Due to the divergent motion of plates, seafloor spreading takes place as a result of which the hot molten magma comes out to the ocean floor and immediately cools down and gets solidified along the mid-oceanic ridge. The rock types produced here are mainly basaltic in nature. Basalt is a mafic rock and is comprised of denser minerals due to which the oceanic crust is relatively denser than the continental crust. Pillow basalts also form in this region.

Thus, the crust that is present beneath the Atlantic ocean is also comprised of basaltic to andesitic in composition.