Relief of Spain: A Geographic Overview

Posted on Oct 29, 2024 in Geology

Relief of Spain

General Features

Spain’s relief is characterized by:

  1. High average altitude: At 660 meters above sea level, Spain is second only to Switzerland in Europe.

  2. Peripheral disposition of reliefs: The main mountain ranges form the boundaries of the peninsula.

    • North: Cantabrian Mountains (1,000-2,500m)

    • East: Iberian Mountains, Coastal-Catalan Range

    • South: Betic Mountains (over 3,000m)

  3. Compact and solid form: This limits the influence of the sea, resulting in a continental climate inland.

Formation and Lithological Variety

The present relief is a result of a long geological evolution:

  • Paleozoic Era (300 million years ago): Hercynian orogeny formed the Hespérico Massif.

  • Mesozoic Era (200 million years ago): A period of erosion and sedimentation.

  • Tertiary Era (65 million years ago): Alpine orogeny resulted in the formation of the Pyrenees, Betic Mountains, and Coastal Catalan Range. The plateau tilted westward.

  • Quaternary Era (1-2 million years ago to present): Glaciers and river terraces shaped the landscape.

Spain has three major lithological zones:

  • Silica Iberia (Western Spain): Composed of Paleozoic materials like granite, gneiss, and quartzite.

  • Limestone Iberia: Formed by Mesozoic sediments folded in the Tertiary. Characterized by karst landscapes.

  • Clayey Iberia: Made up of low-resistance materials like clay and marl, forming plains and basins.

Relief Units

Plateau and Internal Units

The plateau is the core of the Iberian Peninsula, divided by the Central System into the northern and southern sub-plateaus. Internal units include:

  • Central System: Horst and graben system with Paleozoic materials.

  • Montes de Toledo: Lower mountains with Paleozoic materials and apalachense relief.

  • Depressions: Duero basin and La Mancha plain, filled with Tertiary sediments.

Mountain Ridges of the Plateau

  • Galician Massif and Montes de León: Paleozoic materials with traces of glaciation.

  • Cantabrian Mountains: Asymmetry between the slopes facing the plateau and the sea. Divided into western (Paleozoic), central (Mesozoic), and Basque Mountains (Mesozoic).

  • Iberian Mountains: Oriented northwest-southeast. Divided into northern (Paleozoic and sedimentary) and southern parts (limestone).

  • Sierra Morena: A flexure formed by the Alpine orogeny with Paleozoic materials.

Units Outside the Plateau

  • Pyrenees: Axial Pyrenees (Paleozoic) and Pre-Pyrenees (Mesozoic limestone).

  • Coastal-Catalan Range: Northern half (Paleozoic) and southern half (Mesozoic limestone).

  • Ebro Depression: Filled with sediments from surrounding mountains.

  • Betic Systems: Penibética Cordillera (coastal) and Subbética Cordillera (interior), separated by the Intrabético Depression.

  • Guadalquivir Depression: Triangular depression open to the Atlantic, filled with sediments from the Betic Mountains and Sierra Morena.

Island Reliefs

  • Balearic Islands: Extension of the Betic Mountains (Mallorca) and Catalan Coastal Range (Menorca).

  • Canary Islands: Volcanic islands with unique landforms like Mount Teide.

Coasts

  • Cantabrian Coast: Straight with cliffs and beaches.

  • Galician Coast: Characterized by estuaries (rías).

  • Atlantic Coast: Low and sandy with wetlands.

  • Mediterranean Coast: Diverse sectors influenced by mountain ranges and depressions.