What's the word of a theory that states that earths crust and upper mantle are broken into sections which move around on a special layer of the mantle?
Answer:
The Plate Tectonic theory
Explanation:
According to the theory of plate tectonics, the earth's lithosphere is comprised of numerous plates which are commonly known as tectonic plates and are mainly of two types, the continental and oceanic crust.
These plates move over a relatively less dense layer of asthenosphere where the rocks flow in response to deformation. This movement of plates is due to the formation of convection current in the mantle and this currents are formed because of the heat supplied from the interior of the earth.
This is the main driving force for the lithospheric plates to move over the layer of asthenosphere.