GEOLOGY

Detailed explanation-1: -Oceanic crust differs from continental crust in several ways: it is thinner, denser, younger, and of different chemical composition. Like continental crust, however, oceanic crust is destroyed in subduction zones. The lavas are generally of two types: pillow lavas and sheet flows.

Detailed explanation-2: -Earth’s crust is generally divided into older, thicker continental crust and younger, denser oceanic crust.

Detailed explanation-3: -The Earth is covered by two kinds of crust-continental and oceanic. The thinner oceanic crust is normally a little more than four miles thick, while the thicker continental crust is often as much as 25 miles thick. Continental crust is also much less dense than its oceanic counterpart.

Detailed explanation-4: -As stated, oceanic plates are denser than continental ones. This is because they are made of denser rocks. Oceanic plates are typically composed of basalt. Basalts are mafic igneous rocks, which means they have a silica (quartz) content of less than 20% and are created by the cooling of lava.

Detailed explanation-5: -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.