Answer:
The mantle is the middle layer of the earth, and it has a thickness of about 2900 km. It covers approximately 85% of the total earth's volume. This layer is comprised of elements such as oxygen, silicon, magnesium, aluminum, sodium, calcium, and iron. The rocks present here are mostly silicate rocks and are dominant in olivine, pyroxene, iron, and magnesium. These are denser minerals.
The mantle is again sub-divided into 2 distinct parts namely, upper mantle (includes the layer of asthenosphere) and lower mantle.
The upper mantle is comparatively less solid in nature in comparison to the lower mantle, which is marked by the presence of the asthenosphere layer, in which the rocks tend to flow in response to deformation.
