Spain’s Physical Geography: Landforms and Geology
Spain’s Geographical Overview
Spain is a medium-sized European country, covering 505,990 km². Its territory comprises a mainland (97.55% of the surface), the Balearic Islands (0.99%), the Canary Islands (1.45%), and the autonomous cities of Ceuta and Melilla (0.1%).
This area exhibits significant natural diversity, characterized by a variety of terrain and climatic contrasts, as well as human diversity, reflected in an unequal distribution of wealth influenced by natural conditions, leading to diverse economic activities.
Location and Geopolitical Significance
Situated in the North Temperate Zone, Spain lies strategically between two continents (Africa and Europe) and two major bodies of water (the Atlantic Ocean and the Mediterranean Sea). This position has made Spain a natural crossroads for air masses of different origins and a geopolitical meeting point for diverse peoples and cultures throughout history.
Its geographical coordinates range from 43° N to 36° N latitude and from 0° to 3° E longitude, and 0° to 9° W longitude.
Peninsular Relief Features
- Solid Form: Characterized by a large width (west to east = 1094 km) and a relatively straight coastline with limited ruggedness, which restricts the penetration of maritime influence inland.
- High Average Altitude (660 meters): Features high mountain ranges and extensive plateaus in the peninsular interior, with core highlands typically between 600 and 800 meters.
- Mountainous Terrain: Surrounding the central plateau, this terrain curbs the influence of the sea, leading to significant climatic and geographical differences between the coast and the peninsular interior.
Key Geographical Definitions
- Latitude: The angular distance between a point on the Earth’s surface and the Equator, measured using parallels from the Equator to the poles.
- Longitude: The angular distance (angle) between the plane of a place’s meridian and the Prime Meridian, measured from 0° to 180° East or West.
Morphostructural Units of Spain
Spain’s diverse landscape is shaped by several distinct morphostructural units:
The Zócalos (Crystalline Basements)
These are ancient, stable blocks (mesas) formed during the Primary or Paleozoic Era. Composed of rigid siliceous rocks (granite, slate, quartzite, and schist), they resist folding and instead fracture or rupture under tectonic pressure, characteristic of the western half of the peninsula.
The Ancient Massifs
Formed during the Tertiary orogeny through the uplift of blocks from the zócalos. These consist of Paleozoic materials and typically feature soft, rounded summits. Examples include the Central System, Montes de Toledo, Galician Massif, and the western part of the Cantabrian Mountains.
The Folded Mountain Ranges
These are major mountainous elevations resulting from the Tertiary orogeny, formed by the folding of sedimentary materials, primarily limestone, deposited by the sea during the Secondary Era.
- Intermediate Cordilleras: Formed by the folding of materials deposited on the edges of the zócalos (e.g., the Iberian System and the eastern part of the Cantabrian Mountains).
- Alpine Ranges: Formed by the folding of materials deposited in long, deep marine trenches (e.g., the Pyrenees and the Betic Cordilleras).
The Depressions
These are sunken areas formed during the Tertiary period, filled with sediments such as limestone, clay, sandstone, or marl.
- Basins formed by the collapse of a zócalo block due to orogenic pressure.
- Pre-Alpine Depressions: Located on both sides of the Alpine ranges (e.g., the Ebro Depression and Guadalquivir Depression), these formed by decompression following the uplift of the Cordilleras, which led to the collapse of some fragments.