Spanish Geological Formations and Mountain Systems

Major Mountain Systems and Regions of Spain

• Cantabrian Mountains: Cantabria, Basque Country, Navarra, Asturias, León, Palencia, and Lugo.
• Iberian System: Pamplona, La Rioja, Zaragoza, Teruel, Castellón, Valencia, Alicante, and Albacete.
• Sierra Morena: Huelva, Seville, Córdoba, and Jaén.
• Pyrenees: Girona, Lleida, Barcelona, Huesca, Pamplona, and Guipuzcoa.
• Guadalquivir Depression: Huelva, Seville, Córdoba, and Cádiz.
• Central System: Salamanca, Valladolid, Ávila, Segovia, Soria, Guadalajara, and Cáceres.
• Baetic System: Cádiz, Málaga, Granada, Seville, Córdoba, Jaén, Murcia, Albacete, Cuenca, and Ciudad Real.
• Southern Sub-plateau: Badajoz, Cáceres, Toledo, and Ciudad Real.
• Montes de Toledo: Badajoz, Cáceres, Toledo, and Cuenca.
• Coastal Catalan Range: Girona, Barcelona, Tarragona, and Castellón.
• Ebro Depression: Lleida, Zaragoza, Huesca, and Pamplona.
• Northern Sub-plateau: Zamora, León, Burgos, Valladolid, Salamanca, Ávila, and Segovia.

Geological Terms and Landforms

Fault (Falla)

A fracture of the Earth's crust caused by tectonic stress, resulting in the displacement of one crustal portion over another, both vertically and horizontally.

Appalachian Relief

A landform arising from differential erosion, where hard layers form peaks and soft layers erode to create valleys through which river networks are embedded. Example: Montes de Toledo.

Raña

An undergrowth-filled area located between mountain ranges, composed of sedimentary materials from surrounding mountains. Its ground often forms meadows and grasslands (wet herbaceous habitat). Example: Montes de Toledo.

Witness Hill (Cerro Testigo)

Isolated hills of hard rock in a flat area. These high formations are topped by a horizontal surface, created by river erosion of soft layers that leaves the 'witness' flat in the higher area.

Countryside (Campiña)

Lowland characteristics of the northern sub-plateau. The elimination of the overlying limestone layer originates a softer relief composed of clay and soft materials, often utilized for agriculture.

Karst Relief

Relief formed by the dissolution of rock by water. This process creates deep cuts in rock walls, forming vertical and narrow passages. Found in the southern and southeastern Iberian Peninsula.

Zocalo (Basement)

A great set of ancient lands, formed by granite rocks, upon which more modern sedimentary materials lie. These often behave as rigid, hard materials that break rather than fold.