I think that this is an example of excretion of metabolic waste. Metabolic waste are substances that have been left after metabolism that the body cannot make use of and have to removed from the body. Body excretes are in form of water solute except for carbon dioxide which is in form of gas together with water vapor from the lungs.
Lithospheric plates are part of a planetary scale thermal convection system. The energy source for plate tectonics is Earth's internal heat while the forces moving the plates are the “ridge push” and “slab pull” gravity forces
