What happens in deep Earth ?

• The main misconception for this part concerns the state of the mantle. A lot of people still believe that the mantle is a LIQUID layer. The only liquid layer in our Earth is the outer core and, at any moment, the mantle is as SOLID as rocks you can touch on the ground. Nevertheless, conditions of pressure, temperature, composition make the mantle to flow like a fluid on geologic period of time (e.g. tens of million of years).