Geomorphic Processes Overview

Geomorphic Processes

• Processes that create and modify landforms
• Classified as Endogenous (internal) and Exogenous (external)
• Endogenous processes build landforms
• Exogenous processes modify landforms

Endogenous Processes

• Large-scale landform creation and transformation
• Create relief
• Igneous processes:
  • Volcanism: Volcanic eruptions and volcanoes
  • Plutonism: Igneous intrusions
• Tectonic processes:
  • Folding: Anticlines, synclines, mountains
  • Faulting: Rift valleys, grabens, escarpments
  • Lateral Faulting: Strike-slip faults
• Earthquakes are evidence of current tectonic activity

Exogenous Processes

• Also called Gradational Processes
• Involve degradation and aggradation
• Modify relief
• Continuum of processes: Weathering, Mass Wasting, Erosion, Transportation, Deposition
• Driven by Geomorphic Agents: Gravity, flowing water, moving ice, waves and tides, wind, plants, organisms, animals, humans

Degradation Processes

• Also called Denudation Processes
• Processes that wear down landforms
• Includes Weathering, Mass Wasting, Erosion, and Transportation

Aggradation Processes

• Processes that build up landforms
• Include Deposition
  • Fluvial, eolian, glacial, coastal

Weathering

• Disintegration and decomposition of rocks in situ (no transportation)
• Produces regolith
• Begins in microscopic spaces
• Types of weathering:
  • Physical or Mechanical Weathering
  • Chemical Weathering
  • Biological Weathering

Physical or Mechanical Weathering

• Disintegration and decay of rocks due to weather elements: High temperatures, extreme cold, freeze-thaw cycles
• No change in chemical composition
• Examples:
  • Exfoliation: Due to thermal expansion/contraction and pressure release
  • Frost Wedging: Water freezes and expands in cracks
  • Salt Wedging: Salt crystallizes in cracks and expands

Chemical Weathering

• Decomposes rocks through chemical reactions
• Examples:
  • Oxidation: Iron-rich rocks react with oxygen
  • Hydrolysis: Igneous rocks react with water
  • Carbonation and Solution: Carbon dioxide in water reacts with carbonate rocks

Biological Weathering

• Plants and animals contribute to weathering
• Examples:
  • Roots physically break rock
  • Lichens release acids
  • Burrowing animals increase weathering

Mass Wasting

• Movement of rock, soil, and debris downslope due to gravity
• Includes:
  • Talus Cones: Pieces of rock at the bottom of a rock fall
  • Landslides

Erosion and Transportation

• Various geomorphic agents, associated processes, and resulting erosional features
• Flowing Water (Fluvial Morphology):
  • Humid regions: Perennial streams, entrenched channels, rapids, waterfalls, plunge pools, potholes, meandering streams, bank erosion, oxbow lakes
• Wind (Eolian Landscapes):
  • Deflation hollows, ventifacts, yardangs
• Tides and Waves (Coastal Morphology):
  • Sea cliffs, sea caves, sea arches, sea stacks, wave-cut beaches
• Moving Ice (Glacial Morphology):
  • Glacial troughs (U-shaped valleys), hanging valleys, glacial lakes

Deposition

• Various geomorphic agents, associated processes, and resulting depositional features
• Fluvial:
  • Humid regions: Braided streams, sand bars, floodplains, natural levees, distributaries, deltas
  • Arid regions: Alluvial fans, bajadas, piedmont alluvial plains, playas, playa lakes, Salinas (salt flats)
• Eolian:
  • Sand dunes: Barchans, parabolic, transverse, longitudinal, star
  • Sand sheets
• Coastal:
  • Sea beaches, coral reefs
• Glacial:
  • Alpine: Glacial drifts, tills, moraines (lateral, medial, end, terminal, recessional, and ground)
  • Continental: Till plains, outwash plains, drumlins, eskers, kames, erratics

Explore the fascinating world of geomorphic processes that shape our planet's landforms. This quiz covers both endogenous processes, such as volcanism and tectonics, and exogenous processes, including weathering and erosion. Test your knowledge on how these processes interact with the environment.