GEOLOGY

Detailed explanation-1: -The type of rock found in the oceanic crust is basalt. The mean density of material in oceanic crust is 2.7 g/cm3. The continental crust is made up of heavier rocks having density of 3 g/cm3. The solid portion of the Earth is called the Lithosphere.

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: -The answer lies in the composition of the rocks. Continental crust is composed of granitic rocks which are made up of relatively lightweight minerals such as quartz and feldspar. By contrast, oceanic crust is composed of basaltic rocks, which are much denser and heavier.

Detailed explanation-4: -It is formed when lava is cooled near the surface of earth. 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.

Detailed explanation-5: -Basalt. Basalt is a hard, black volcanic rock. Basalt is the most common rock type in the Earth’s crust. Depending on how it is erupted, basalt can be hard and massive (Figure 1) or crumbly and full of bubbles (Figure 2).