Convergent boundaries occur wherever the Earth’s tectonic plates move or collide toward each other.
As the plates converge, the denser, thinner tectonic plate sub-ducts or dives beneath the lighter, thicker, more buoyant tectonic plate.
As shown in the picture, the plates are composed of rigid lithosphere consisting of the crust of the earth and the uppermost mantle. Movement of the plates is driven by convection in the asthenosphere and lower mantle, which are softer and warmer than the lithosphere and can flow on geologic timescales. Convection is fuelled by heat generated from radioactive decay of elements in the Earth.
