Question

Which statements describe oceanic crust? Select the two correct answers.

Answer 1

C. It is between 25 and 70 km thick.

Answer 2

Answer:

A. It contains silicate materials high in iron and magnesium.

E. It is formed at zones of volcanic activity on the ocean floor.

Explanation:

    Oceanic crust is the name given to the terrestrial lithosphere layer, with specific characteristics of composition, thickness and differentiated densities, which constitute the bottom of the ocean basins. This together with the Continental Crust constitute the Earth Crust, yet they are completely distinct in composition, thickness and geological history.

Characteristic and its Composition:

• has a thickness of 5 to 10 km (rarely exceeding 10 km);

• it is denser than the continental crust, varying from region to region;

• In its composition there are mafic materials of the Basalt and Gabon family, which are rich in ferromagnetic minerals, due to this composition the oceanic crust is called sima (silicon and magnesium), opposing to sial (silicon and aluminum) continental crust.