Geography 101: Landforms and Formation

Mountain Formation

• Types of Mountain Formation:
  • Folding: compression of Earth's crust, resulting in folded mountains (e.g. Himalayas)
  • Volcanic: volcanic activity creates mountains (e.g. Mount St. Helens)
  • Block: movement of large blocks of Earth's crust, resulting in block mountains (e.g. Sierra Nevada)
  • Dome: uplift of Earth's crust, resulting in dome-shaped mountains (e.g. Appalachian Mountains)
• Factors Influencing Mountain Formation:
  • Plate tectonics: movement of tectonic plates
  • Geologic processes: weathering, erosion, and deposition

Plate Tectonics

• Theory: Earth's crust is broken into large plates that move relative to each other
• Types of Plate Boundaries:
  • Divergent: plates moving apart (e.g. Mid-Atlantic Ridge)
  • Convergent: plates moving towards each other (e.g. Himalayan orogeny)
  • Transform: plates sliding past each other (e.g. San Andreas Fault)
• Effects of Plate Tectonics:
  • Earthquakes: movement of tectonic plates
  • Volcanic activity: movement of tectonic plates
  • Mountain formation: movement of tectonic plates

Volcanic Landforms

• Types of Volcanoes:
  • Shield: gently sloping, large volcanoes (e.g. Hawaiian Islands)
  • Composite: tall, conical volcanoes (e.g. Mount Fuji)
  • Cinder: small, steep-sided volcanoes (e.g. Mount Vesuvius)
• Volcanic Features:
  • Craters: depressions formed by volcanic activity
  • Lava flows: molten rock flowing from volcanoes
  • Volcanic fields: areas of multiple volcanoes

Desert Landscapes

• Characteristics of Deserts:
  • Low rainfall: less than 25 cm/year
  • High temperatures: extreme heat and cold
  • Limited vegetation: sparse plant life
• Desert Features:
  • Dunes: sand ridges formed by wind
  • Oases: isolated areas of vegetation and water
  • Canyons: deep valleys formed by erosion

Coastal Features

• Types of Coasts:
  • Emerging: coastal areas rising due to tectonic activity
  • Submergent: coastal areas sinking due to tectonic activity
  • Volcanic: coastal areas formed by volcanic activity
• Coastal Features:
  • Beaches: areas of sand and pebbles
  • Cliffs: steep slopes formed by erosion
  • Headlands: rocky outcrops formed by erosion