This thesis elaborates on the evolution of the continental upper mantle based on numerical modelling results. The descriptive and explanatory basis is formed by a numerical thermo-chemical convection model. The model evolution starts in the early Archaean about 4 billion years ago. The model follows from the conservation equations, which are based on the physical laws describing the upper mantle. Several simplifications have been made as is common practice in model studies. Nowadays, modern high- and top-end computers pave the way for these increasingly realistic simulations. Qualitative scenarios can now be tested and furthermore modelling may reveal new dynamical concepts, which had not been proposed.