Iberian Peninsula: Mountain Ranges and Geology
Mountain Ranges of the Iberian Peninsula
The mountainous Chimes Plateau originated in the Tertiary period through the rejuvenation of blocks or by the folding of material deposited by the sea during the Secondary Era at the edges.
a) Galaico-Leonese Massif
Located in the northwest corner of the plateau, it fractured and rejuvenated due to the Alpine orogeny. It features both Paleozoic materials and mountains with rounded tops and low elevation (Segundera, Ancares). The massif ends in steep slopes.
b) Cantabrian Mountains
Arranged (from east to west) and isolated from atmospheric influences on the northern plateau. Two areas can be distinguished:
- Asturian Massif (western sector): Paleozoic materials rejuvenated by the Tertiary orogeny. Highlights include the Picos de Europa (Torre Cerredo, Naranjo de Bulnes).
- Cantabrian Mountains (eastern sector): Secondary limestone materials deposited by the sea during the Secondary Era.
c) Iberian System
An extensive mountainous area consisting of mountains and depressions. It mostly presents secondary material folded during the Alpine Orogeny. It has two sectors:
- North Sector: Sierra de la Demanda, Moncayo, Picos de Urbión.
- Southeast Sector: Opens into two branches: an outer or Aragonese branch and an inner or Castilian branch. Both are separated by a rift valley (Calatayud pit).
d) Sierra Morena
A step that separates the plateau from the Guadalquivir depression. It is interpreted as a flexure of the land with many faults, produced by the southward thrust of the Andalusian ranges. The main ranges are Madrona and Aracena.
External Cordilleras of the Plateau
They formed during the Alpine Orogeny in the Tertiary period by the folding of material deposited in ocean trenches.
a) The Pyrenees
Forming the border between Spain and France, they have a complex structure. The axial area is of Paleozoic material and presents the highest relief (Aneto and Monte Perdido in the Maladeta Massif). To the south is the area of the Pyrenean foothills, of secondary material, structured in two alignments under high stress and soft shapes. Quaternary glacial modeling has been significant.
b) The Basque Mountains
A prolongation of the Pre-Pyrenees, with low elevation and smooth forms, such as the peaks of Aralar and Gorbea.
c) Cordillera Costero-Catalana
Separates the Ebro basin from the Mediterranean and is a transformation of the eastern Pyrenees, separated from these by faults that have led to a well-preserved volcanic region. The range is divided into two alignments, with the interior higher than the coastal one and separated by a longitudinal depression or pit.
d) Betic Cordilleras
Represent the largest mountainous unit of the peninsula, stretching from the Gulf of Cadiz to the Alicante Mediterranean.
- The Penibetic Cordillera runs along the coast, formed by ancient Paleozoic materials of the Betic-Rif mountain range. Sierra Nevada highlights include the Mulhacén (highest peak in the Peninsula, 3,482 m) and Veleta peaks.
- The Subbetic Cordillera: A lower mountainous area, bordering the Guadalquivir valley, with secondary materials deposited by the sea in the Betic trough. The Intrabetic Depression lies between the two cordilleras.