Attempt to amplify the above Which is cause and which effect If you consider the continents to be at any given time floating like pucks on an air hockey table in extreme slow motion then once they move they keep on going until stopped This presupposes a lateral acceleration to get them moving the build up of sufficient momentum to keep them going against resistance from tectonic activity and a purely mechanical consideration of energy absorption during collisions These collisions may therefore spark one of absorption of the crust subduction folding collision or bouncing the continents may strike a glancing blow and further motion may be reversed or rotation may take over like two air hockey pucks hitting each other If you keep on going in this reasoning there seems to be little reason why a supercontinent would split in the first place Although it seems that the continental crust may be weakened by thermal effects if it splits in the middle of the continent you would need an enormous push to get things moving as the supercontinent must be well anchored and have maximum inertia One might expect that a volcanic ridge would form and overflow rather than actually create tectonic plates or that volcanic action would be confined in perpetuity to the plate edges Once in motion however the parts of that supercontinent would in the absence of other forces move around the globe and then meet up again in a different configuration The other forces are what complicates matters The original energy available in the original rifting is not known nor are the stiffnesses of the rocks around where it occurred we always work backwards in time stating that rifting seems to have occurred here and there It also seems to be directional discontinuous and unstable look at what seems to have happened to Africa Antarctica and Australia during their split from Pangaea India hurries north Australia flies west Antarctica shuffles south and Africa moves a little north while Madagascar moves in the opposite direction or possibly stays where it was but that is a private opinion In addition one can not assume that these events are not counteracted elsewhere the passage of a continent must cause ructions along all its edges and this around the globe so one rifting may influence another If a plate moves say east will it produce rifting along its western edge and will this act as an outboard motor to keep it accelerating Furthermore the whole earth is in motion spinning on its axis with gravitational forces involved that can also influence the dispersion of crustal plates It is a many body problem with far too many factors involved for more than top level analysis by myself as a layman