Just as 30° separate main topography of the world at equator today, a 30° pattern can be recognized of Pangea 200 million years ago. The convection currents must then have been coupled and de-coupled in a favorable way so that breakup of the tectonic plate could take place. The breakup occurs mainly along the main division lines of lower mantle large scale convection rolls as shown here.
It is notable that Iceland during that time, Iceland was located over a large scale downwelling line. During the breakup, the area wher Iceland is now located moved over the next division line, namely the upwelling line of the center of the emerging Atlantic Ocean. Therefore, that part of the Atlantic Ocean started to break up later than the central pars closer to equator.
.https://en.wikipedia.org/wiki/Pangaea
To clarify further, what has happened after the break-up of Pangea, you can have a look at this drawing of the equatorial plane of the Earth, showinig the convection rolls pattern.
The upwelling division line did break S-America away from Africa, and then it drifted over to the other convection roll. The same happened to Africa, but it also drifted northwards, so that now it only spans 30° from east to west. The northwards, and more irregular drift also led to the fact that the coastline is slightly east of the division line, leading to the formation of the Great Rift Valley over the corresponding upwelling large scale division line.
Magic Magma 