Which crust type is predominantly composed of granitic rocks and forms the landmasses?

Which crust type is predominantly composed of granitic rocks and forms the landmasses?

• A. Mantle
• B. Oceanic Crust
• C. Continental Crust
• D. Core

Answer: (C)

Crusts differ in composition and density, which determines where they sit. Continental crust is predominantly granitic, made of light-colored, silica-rich rocks like granite and granodiorite. Because these rocks are less dense than mantle rocks, continental crust sits higher and forms the landmasses we see above sea level. In contrast, oceanic crust is mainly basaltic and denser, forming the ocean floors. So the landmasses are underlain by continental crust.

Crusts differ in composition and density, which determines where they sit. Continental crust is predominantly granitic, made of light-colored, silica-rich rocks like granite and granodiorite. Because these rocks are less dense than mantle rocks, continental crust sits higher and forms the landmasses we see above sea level. In contrast, oceanic crust is mainly basaltic and denser, forming the ocean floors. So the landmasses are underlain by continental crust.