Today, Spain and Northern Africa face each other across the boundary between the African Plate and the Eurasian Plate with the two plates gently converging obliquely. The current rate of convergence is just 4-6 mm / year - quite sedate in global and historical terms, but it was not always so.
On most published maps, this boundary between the Eurasian and African Plates is shown as a nice simple line running through the middle of the Mediterranean, This belies its true complexity which is neatly illustrated by a map of the world's earthquakes below.
The map is a plot of all earthquakes between 1963 and 1998, and naturally shows a strong concentration of activity along the major plate boundaries. Some types of Plate margin have sharply demarcated earthquake activity associated with them - e.g. the Mid-Atlantic Ridge - which indicates a relatively tightly focused interaction between the two plates on either side.
However, the boundary between the Eurasian Plate and the Plates to the south, shows a highly diffuse spread of earthquake activity. This is because over the last 50 million years or so, the African, Arabian and Indian Plates have converged directly on Eurasia in a complex set of collisional Plate interactions that have jumped around in terms of their precise timing, location, style and intensity. The result has been a broad swathe of mountain building, creating a string of some of the world's most famous ranges known collectively as the Alpine-Himalayan orogenic belt. (The term 'orogenic' comes from the Greek words 'oros' meaning mountains, and 'genes' meaning 'born' or 'produced').
The Betics mountains of southern Spain and the Rif mountains of Morocco are part of this Alpine-Himalayan orogenic belt and have the distinction of marking its western terminus. Although genetically related, therefore, to its more famous relatives such as the Alps and Himalayas, the detailed evolution of the Betics has its own very distinctive and somewhat unusual story.