GEOLOGY

Detailed explanation-1: -3. The density of basaltic rocks is more than granitic rocks and because of this the sial is lighter than sima.

Detailed explanation-2: -Their densities are mostly determined by their mineral content. Felsic igneous rocks (with high silica content) such as granite, will generally be less dense than mafic igneous rocks, such as basalt, which have more iron rich minerals.

Detailed explanation-3: -Continental crust is broadly granitic in composition and, with a density of about 2.7 grams per cubic cm, is somewhat lighter than oceanic crust, which is basaltic (i.e., richer in iron and magnesium than granite) in composition and has a density of about 2.9 to 3 grams per cubic cm.

Detailed explanation-4: -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.

Detailed explanation-5: -Two of the heaviest or densest rocks are peridotite or gabbro. They each have a density of between 3.0 to 3.4 grams per cubic centimeter. Interestingly, peridotite are the rocks that naturally occurring diamonds are found in.