GETXO
THE GRAND COUPURE
THE SYNCLINE FOLD OF PUNTA GALEA
Do you know what syncline means? It's a V shaped fold in the sedimentary strata, so the layers of the rocks are convex going downwards.
As you know, the Pyrenees were formed by the collision between the Eurasian and Iberian tectonic plates. That event was part of the period when most of the mountains we have today in Europe and Asia were formed. It's called the Alpine orogeny and it lasted more than 20 million years. So the Punta Galea syncline was created because of the collision of tectonic plates and its axis goes from the coast up to mount Oiz.
The syncline can be seen easily from the sea. Overland access to the observation area is very difficult. But, from the Flysch route you can get an idea of the inclination of the sedimentary layers towards the east in Punta Galea and towards the west after Tunelboka.