Geology

Layers of the Earth

The first layer is the crust. The crust is the layer that everyone builds, mines and lives on. The crust goes from 50km on land to 7km in the ocean. It is the outermost layer of the earth.

The second layer is the mantle, which is much hotter than the crust and is chemically different from it. It also contains a smaller layer - The asthenosphere - in the uppermost portion of the mantle, which behaves like plasticine. The rock flows much more slowly than in the asthenosphere, so slowly that the rock here can be considered rigid.

The third and fourth layers are the core. The outer core - the 3rd layer - is more liquid than the inner core, the 4th layer, which is solid. Both are thought to be mostly composed of iron and nickel.

Minerals

Minerals are naturally occurring chemical substances that make up igneous, sedimentary and metamorphic rocks.