Horizontally Layered Rocks Formation

Horizontally Layered Rocks

• Form where layers of rocks are flat lying, resulting from sediments deposited by wind and water
• Sediments are turned into rocks over millions of years as more layers are deposited
• Formed when:
  • Horizontal sedimentary rocks are uplifted without changing position
  • Lava flows on the surface cool, forming layers of igneous rocks
  • A sill (igneous intrusion) is exposed to the surface

Hilly Landscapes

• Influenced by climate and rock resistance
• In humid areas:
  • Large amount of rainfall leads to erosion through sheet wash
  • Smooth and rounded hills form
• In dry/arid areas:
  • Less rainfall leads to less water erosion
  • Rugged hilly landscapes with steep slopes and little rounding form
  • Can also be referred to as Badlands, characterized by steep slopes and minimal vegetation

Basaltic Plateau

• Formed by lava pouring out of long narrow cracks in the ground
• Built up over millions of years, forming deposits hundreds to thousands of meters thick
• Example: The Drakensberg, a popular tourist destination

Canyon Landscapes

• Develop where horizontal layers erode at different rates
• Running water finds weak places in the hard surface layer, eroding vertically into the land
• Form deep valleys with stepped sides and resistant rock forming steep cliffs
• Less resistant rocks form gentler slopes
• Example: The Grand Canyon in the USA

Uses of Canyons

• Can be dammed to make very deep dams, often used for hydro-electric power
• Surrounding plateau may be too dry for agricultural value
• Impressively scenic, making them popular tourist attractions

Karoo Landscapes

• Develop from canyon landscapes
• Plateau remains the same height due to cap rock
• Large areas are covered with horizontal layers
• Rivers erode vertically, forming canyons with landforms like Mesas, Buttes, and Conical Hills
• Example: The Blyde (Motlase) canyon in Mpumalanga