The Upper Mantle is the uppermost portion of the Earth's mantle. It is composed of relatively cool rocks such as peridotite and basalt. The temperature is typically between 500 and 1000 degrees Celsius. It is mainly composed of minerals such as olivine, pyroxene, and garnet. It is relatively rigid and is the main source of orogeny.
The Lower Mantle is the portion of the Earth's mantle located below the upper mantle. It is composed of hot, dense rocks such as eclogite and dunite. The temperature is typically between 1000 and 2000 degrees Celsius. It is mainly composed of minerals such as bridgmanite, ferropericlase, and magnesiowüstite. It is ductile and is the main source of convection, which drives plate tectonics.