Relief Units of Spain: Mountains and Plateaus
Spanish Relief Units
The Plateau and Indoor Units
The plateau exceeds an average height of 600 meters and is divided into two halves by the Sistema Central. The northern plains, with an average altitude over 700 meters, coincides geographically with the Duero basin. South of the Sistema Central extends the southern plains of the Meseta. Morphological traits are derived from its status as the old solid end of the Primary Era to the present Mediterranean, which was secondary. Alpine folding affected it as the base acted as a stop before the orogenic thrust. Consequences:
- Fracturing
- Folding
- Central Basculamiento
Sistema Central: Formed by a string of mountains that stretch along 400 km. Follows an east-west alignment. Notable ranges include Somosierra, Guadarrama, and Gredos.
Montes de Toledo: These are minor mountains. Their summits do not exceed 1600m, highlighting the Reboiler, Mussel, Pocito, and Guadalupe peaks. In the foothills, irregularly sized materials called frogs have been deposited.
The Mountain Ridges of the Plateau
The non-solid block mountains of Galicia and Leon are part of the primitive base of the plateau, composed here of granitic and metamorphic rocks. The area occupied by the two systems is crossed by a network of faults, among which are those of north-south and the cross, which leads to the estuaries. Further inland lie the Montes de León, authentic ends of the Plateau, which rise above 2000 meters. The higher altitudes contain important traces of glaciers, most notably Lake Sanabria.
Cantabrian Mountains: These form the northern edge of the plateau. It extends from Galicia to the Basque Country over 600 km in height, aligned parallel to the Cantabrian Sea. Under its apparent unity, a variety is hidden inside, expressed in the existence of three distinct sectors:
- Western or Asturian Sector: Has an affinity with the Galician Massif.
It consists of Paleozoic and other materials from the Carboniferous period. The folds of the mountains in this area are oriented north to south and are very distorted by the subsequent action of the Alpine folding.
- The Central Sector of the Cantabrian mountain range spans. In contrast to the western sector, it consists of materials from the Secondary Era. These materials are under the powerful banks of sediment deposited in the deep sea.
- Montes Vascos: Represent a threshold extending between the Cantabrian and Pyrenees mountains. They culminate in Aitzgorri and Peña Gorbea and have similarities with the central sector of the range.
The Iberian System
This range stands out as the only Spanish mountain range that is considered important from northwest to southeast. Its origin is related to two facts: the original slope of the plateau to the east and the strength of the Alpine folding. During its course, there are two parts:
- The northern part has important mountains, which account for a more important orographic core status of water dispersant to the basins of the Duero.
- Southern Sector: A wider Iberian range, with less precise contour and alignment. Two branches can be distinguished: an inner and an outer.
Sierra Morena
This mountain range is related to the color of vegetation. It occupies the southern edge of the plateau, which represents the lip destroyed by erosion and rejuvenated in the Tertiary Era. Its constituent materials are mostly Paleozoic slates and quartzite. The geological structure responds to the guidance of Armorican folds. It offers a remarkable case of asymmetry between its northern and southern slopes.