Geomorphology of the Iberian Massif: Relief and Landforms

Relief Units of the Iberian Peninsula

The Iberian Massif Central (The Plateau)

1. The Peneplains

Located in the western peninsula, the peneplains are characterized by:

• Central Granite: Granite outcrops as small balls, becoming altered into highly permeable sandy mantles. Features include V-shaped valleys and granite domes.
• Slate Peneplains: Generally flat areas between 800 and 1000 meters in altitude, decomposed into reddish clay and rubble. These follow SE-NW alignments.
• Zamora Slate: Displays significant erosion in valleys with quartzite crests remaining as highlights.

2. Mountains of Blocks

Formed within the Iberian Massif Central due to the Alpine Orogeny:

• Central System: Divides the Northern and Southern Submeseta.
• Montes de Toledo: Separates the Southern Submeseta between the Tagus and Guadiana rivers.

3. Sedimentary Basins

The interior of the Iberian Massif, located on both sides of the Central System, consists of sunken socket areas from the Alpine Orogeny filled with sediment.

Differences Between Submesetas

• Altitudinal: North (700–1000 m) vs. South (600–800 m).
• Drainage: The North is drained by the Duero; the South is drained by the Tagus, Guadiana, and the Júcar in Albacete.

Key Landforms

• Páramo: Flat, high areas crowned by a limestone layer resistant to erosion. Erosion has carved U-shaped river valleys.
• Campiña: Gently rolling plains crisscrossed by rivers that have dismantled the top of the moors.
• Raña Deposits: Found at the foot of the Central and Toledo Mountains. These are collections of detrital quartz in a sandy-clay matrix, arranged as alluvial fans.

The Sedimentary Basin of the Duero

• Wastelands (Páramos): Located in the NE of the basin, these are elevated platforms with horizontal limestone strata protecting the underlying clay.
• Vargas: Small valley penetrations into the moor.
• Witness Hills (Cerros Testigo): Small, isolated patches of wilderness.