Spanish Mountain Ridges: Galician Massif, Cantabrian, Iberian, Sierra Morena
Mountain Ridges of Spain
Mountain ridges — they are the main: Galician Massif, the Cantabrian Mountains, the Iberian System and the Sierra Morena. They formed in the Tertiary by the rejuvenation of blocks of the plateau:
Galician Massif
The Galician Massif was the northwestern corner of the plateau's basement (zócalo) that fractured and rejuvenated during the Alpine orogeny. This material consists of Paleozoic rocks and features rounded, low-lying mountains cut by a multitude of saws. Among its most outstanding elements are Second Hand and Ancares Cabrera.
Cantabrian Mountains
The Cantabrian Mountains have two distinct areas. In the west, the Asturian Massif is composed of Paleozoic materials that were part of the plateau's zócalo and were rejuvenated in the Alpine orogeny. At the western end, the hardness of slate and quartzite materials has given rise to Appalachian-type reliefs.
At its eastern end there is a large limestone outcrop that constitutes the primary peaks in Europe where the highest summits of the mountains are found. To the east, Mesozoic limestone materials were deposited by the sea on the edge of the plateau and were folded during the Alpine orogeny.
Iberian System
The Iberian System is an intermediate range formed mostly by Mesozoic materials deposited by the sea on the edge of the plateau, which were folded in the Alpine orogeny. Paleozoic material appears in some sectors where the Cenozoic cover was thin and allowed the outcrop of the zócalo, rejuvenated by the Alpine orogeny.
It can be distinguished in several sectors: the third sector, northwest to southeast, contains the highest peaks of the system. Soria is included in this region. From the southwest the Iberian System is divided into two branches: an inner (Castilian) branch and an outer (Aragonese) branch, both separated by a rift valley filled with Tertiary materials.
Sierra Morena
The Sierra Morena is not really a mountain range in the strictest sense but rather a sharp step between the plateau and the Guadalquivir Valley. It was originally seen as a huge fault, but it seems to be a great area broken in many places by flexures produced by the thrust from the south as the Betic Cordillera rose.
The dark Paleozoic rock, together with its dark vegetation, gives the name Sierra Morena. Its most prominent mountains are Madrona, Pedroches and Tariffs.
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