During the "magma convection currents", the platetectonics are pulled apart from each other. This is because if the "magma convection currents" flow in opposite direction, the plates present floating on the molten magma also float apart, causing divergent plate boundaries.
The plate tectonics are responsible for the movement of continental plates. The molten magma present inside the earth acts as a vast ocean on which the plates move as sheets. So if currents flow away from each other they take the plates along with them too, forming great rift valleys.
