Understanding Landforms: Tectonics and Stress Factors

Tectonic Dispositions

• Horizontal or Aclinal Relief: Self-sedimented areas with horizontal strata, alternating hard and soft layers. Water systems erode softer layers, creating residual relief.
• Monoclinal Relief: Gently sloping sedimentary areas with alternating hard and soft materials. Erosion forms steep slopes and isolated hills.
• Faulted or Germanic Structure: Results from pressure exceeding rock deformation capacity, leading to fractures, uplifted blocks, and sunken areas.
• Folded Relief: Formed by folding of sedimentary rocks due to compression. Anticlines are prone to erosion, while synclines retain more compact materials.

Appalachian Relief

Folded relief leveled by erosion, forming a base.

Jurassic Relief

Found in young mountain ranges with alternating convex and concave folds. Erosion valleys form perpendicular to peaks in anticlines and parallel in valleys.

Stress Factors

Silica Area

Consists of old primary materials (granite, slate, gneiss, quartzite) found in the western peninsula and extending to the Central System, Montes de Toledo, and Sierra Morena.

• High Mountains: Rocks break due to water freezing in cracks, forming ridges, jagged peaks, and scree.
• Lower Elevations: Perpendicular joints form balls, which can stack to create Barrancal.

Limestone Area

Comprised of secondary limestone sediments, folded in the Tertiary.

• Limestone Terrain: Dominant rock is limestone, which fractures easily but dissolves in rainwater.
• Sinkholes or Lenar: Formed by water furrows on slopes or cracked surfaces. Shapes vary based on crack proximity and surface flatness.
• Gorges or Ravines: Deep, narrow valleys with steep slopes caused by rivers.
• Dolinas or Uvalas: Cavities formed where water stagnates, with various shapes and depressions.
• Cuenca: Created when water seeps through limestone cracks, forming underground circular formations with stalactites. Water can resurface through springs.
• Saws: Narrow openings connecting the surface with underground galleries.

Clay Area

Formed by sedimentation, very resistant to erosion.

• Clay Terrain: Clay creates horizontal relief in areas unaffected by folding. Rivers cover valleys, forming undulating relief. Water erosion creates slopes and deep, narrow hollows.