Spanish Geography: Exploring Spain’s Diverse Landscapes

Posted on Nov 26, 2024 in Geology

Geographical Overview of Spain

Spain, a medium-sized European country (505,990 km2), comprises a mainland (97.55%), the Balearic Islands (0.99%), the Canary Islands (1.45%), and Ceuta and Melilla (0.1%). This diverse area boasts a rich variety of human and natural landscapes.

Location

Spain is situated in the temperate Northern Hemisphere, between Africa and Europe, and the Atlantic Ocean and the Mediterranean Sea. This unique location has made Spain a crossroads of natural and geopolitical significance (43ºN to 36ºN, 0º to 3ºE, and 0º to 9ºW).

Peninsular Relief

Characteristics

  • Solid form
  • Great width (west to east = 1,094 km)
  • Relatively straight coastlines
  • High average altitude (660 meters)

High mountain ranges and a central plateau dominate the peninsular landscape, limiting maritime influence and creating significant differences between the coast and inland areas.

Morphostructural Relief Types

  1. Sockets: Plateaus formed in the Paleozoic era.
  2. Ancient Massifs: Mountains formed during the Tertiary orogeny, featuring uplifted Paleozoic materials and soft, rounded curves (e.g., Central System, Montes de Toledo, Galaico Massif, western Cantabrian Mountains).
  3. Folding Ridges: Large mountain ranges of Tertiary orogeny, formed by the folding of sedimentary materials, primarily limestone deposited during the Mesozoic era.
    • Intermediate Ridges: Formed by the folding of materials deposited on the edges of the baseboards.
    • Alpine Ranges: Formed by the folding of materials deposited in deep trenches (e.g., Pyrenees and Baetic Cordillera).
  4. Depressions: Sunken areas formed in the Tertiary era and filled with sediments like limestone, clay, sandstone, or marl.
    • Prealpine Depressions: Located on both sides of the Alpine ranges (e.g., Ebro and Guadalquivir depressions), formed by decompression following the uplift of the Cordilleras.

Peninsular Rock Types and Relief

Three distinct geological areas characterize the Iberian Peninsula:

  1. Silica: The oldest area, occupying much of the western peninsula, composed of granite, gneiss, slate, and quartzite. Erosion creates gently rolling landscapes or rounded rock formations (scree).
  2. Limestone: Formed from Mesozoic sediments, creating an inverted ‘Z’ shape across the peninsula. Composed of limestone, conglomerates, sandstones, and marls. Erosion results in karst landscapes with sinkholes, caves, chasms, and poljes.
  3. Clay: Composed of Tertiary and Quaternary sediments, stretching across the plains of Castile and the Ebro and Guadalquivir basins. Composed of clay, marl, and gypsum. Erosion leads to gullies and badlands.

Morphostructural Relief Units of the Peninsula

  • Meseta Central (Central Plateau): A high plateau divided by the Central System, surrounded by mountain ranges and two exterior basins. Composed of Paleozoic bedrock and penillanuras (flat, eroded surfaces).
    • Northern Sub-plateau: Higher and more uniform.
    • Southern Sub-plateau: Lower, divided by the Montes de Toledo.
  • Mountain Ranges within the Meseta: Central System and Montes de Toledo (with gentle peaks).
  • Sedimentary Basins within the Meseta: Located in the northern and southern sub-plateaus.
  • Mountainous Borders of the Meseta: Galician-Leonese Massif, Cantabrian Cordillera, Iberian System, and Sierra Morena (a sharp escarpment between the Meseta and the Guadalquivir Valley).
  • Depressions outside the Meseta:
    • Ebro Depression: Parallel to the Pyrenees, with flat relief.
    • Guadalquivir Depression: Parallel to the Baetic Cordillera, with gently rolling plains and mesas.
  • Mountain Ranges outside the Meseta:
    • Pyrenees: Complex structure.
    • Basque Mountains: Two alignments, one parallel to the coast and a higher inner range.
    • Baetic Cordillera: Highest peaks in the peninsula, with distinct ranges (Penibaetic, Subbaetic, and Intrabaetic).