Spain's Physical Geography: Landforms and Relief

Spain's Geographical Landscape

Spain encompasses a diverse geographical space with a total area of approximately 505,987 km².

Regional Geographical Areas

• Peninsular Spain: 493,516 km²
• Balearic Archipelago: 4,992 km² in the Mediterranean Sea, including Mallorca, Menorca, Ibiza, Formentera, Cabrera, and approximately 150 smaller islets.
• Canary Islands: 7,447 km², comprising La Palma, El Hierro, La Gomera, Tenerife, Gran Canaria, Fuerteventura, Lanzarote, and other smaller islands.
• Ceuta and Melilla: Ceuta covers 19.6 km² (located near the Península de Yebala), and Melilla covers 12.3 km² (characterized by land and water boundaries).

Peninsular Relief Features

The relief of Peninsular Spain is characterized by massive forms, high altitudes, and the distinct arrangement of its peripheral mountain ranges.

Types of Morphostructural Units

A) Basement Units

These are plains or tablelands formed in the Primary Era as a result of the erosion and leveling of mountain ranges from the same orogenic era. Composed of rigid Paleozoic silicate rocks (such as granite, quartzite, and slate), these areas were not folded by subsequent orogenic movements. They primarily occupy the western half of the peninsula.

B) Ancient Massifs

These are mountains re-elevated in the Tertiary Era due to the re-elevation of basement blocks under the pressures of the Alpine Orogeny. They typically feature rounded shapes and eroded, flattened surfaces, despite their high altitude. Examples include the Inner Meseta (Central System, Montes de Toledo), the Galician Massif, and the western part of the Cantabrian Mountains.

C) Folded Mountain Ranges

These are significant mountain ranges that emerged during the Alpine Orogeny in the Tertiary Era through the folding of sedimentary materials.

• Intermediate Ranges: Formed by the folding of materials deposited by the sea along the margins of ancient basins (e.g., the Iberian System and the eastern part of the Cantabrian Mountains).
• Alpine Ranges: Formed by the intense folding of materials deposited in geosynclines (long, deep troughs) (e.g., the Pyrenees and the Betic System).

D) Sedimentary Basins or Depressions

These units were formed in the Tertiary Era and are filled with sediments, primarily limestone and clays.

• Basins formed by Block Subsidence: Resulting from the subsidence of a basement block due to the pressures of the Alpine Orogeny (e.g., the Duero and Guadiana Basins).
• Pre-Alpine Depressions: Located on both sides of the Alpine mountain ranges (e.g., the Ebro and Guadalquivir Depressions). Their formation is due to the erosion following the uplift of the ridges, which caused subsidence in certain sectors.