INDIAN GEOGRAPHY

Detailed explanation-1: -Oceanic crust which extends 5-10km beneath the ocean floor is primarily composed of basalt rocks. Oceanic crust is constantly formed in mid-oceanic ridges where tectonic plates move apart forcing lava to well up and cool down. Basalt is fine grained and dark coloured rock.

Detailed explanation-2: -Oceanic crust is generally composed of dark-colored rocks called basalt and gabbro. It is thinner and denser than continental crust, which is made of light-colored rocks called andesite and granite. The low density of continental crust causes it to “float” high atop the viscous mantle, forming dry land.

Detailed explanation-3: -Oceanic crust is primarily composed of mafic rocks, or sima, which is rich in iron and magnesium.

Detailed explanation-4: -Oceanic crust is created as magma rises to fill the gap between diverging tectonic plates and is consumed in subduction zones. It is geologically young, with a mean age of 60 Ma, and is thin, averaging 6.5 km in thickness. Oceanic crust consists almost exclusively of extrusive basalt and its intrusive equivalents.

Detailed explanation-5: -Ocean crust is formed from molten material at the ocean ridge systems. Lava and intrusive rocks combine to form the crust. The molten material that solidifies to form new oceanic crust is mafic in composition. The rocks basalt and gabbro are the result.