I feel like we underestimate the importance of the Reykjanes Ridge when dealing with the geology of Iceland. Look at that big feature! Most important is found above the convection rolls!
The basics of the Reykjanes Ridge can be described in a very simple way. To make it clear, let us have a look at this drawing of convection rolls with a Google map with division lines added:
The SW corner of Iceland can be seen. The Reykjanes Ridge ends there. Instead volcanic systems are found en echelon along the Reykjanes Peninsula.
The Reykjanes Ridge is the most typical feature to begin studying the convection cell system. Two convection rolls, forming one pair of upwelling, creating a distinct feature of a Mid Ocean Ridge. The alignment of the ridge fits perfectly to the calculations made according to the Coriolis Force acting on mantle material flowing slowly under perfectly balanced conditions.