Geography Chapter 02: Inside Our Earth

The earth is made up of several concentric layers with one inside another. The uppermost layer over the earth’s surface is called the crust. The main mineral constituents of the continental mass are silica and alumina. The oceanic crust mainly consists of silica and magnesium.

Just beneath the crust is the mantle which extends up to a depth of 2900 km below the crust.

The earth’s crust is made up of various types of rocks. There are three major types of rocks: igneous rocks, sedimentary rocks and metamorphic rocks.