Surface processes W/E/D GM

• Weathering is the breakdown of rock into sediments due to processes at the Earth’s surface
• Physical weathering changes only size & shape of rock (disintegration), composition remains the same
• Chemical weathering involves chemical reactions that change the composition of rock (decomposition)
• Physical weathering processes include: Frost wedging, Abrasion, Organisms, Exfoliation
• Chemical weathering processes include: Oxidation, Hydrolysis, Carbonation, Organism
• Frost Wedging:

  • Water gets into cracks, freezes & expands, causing the rock to break
  • Common in freezing temperatures, causes potholes
• Abrasion:

  • Rocks rub and bounce against each other, breaking into smaller pieces
  • Wind, moving water, and glaciers/ice can cause abrasion
• Organisms:

  • Plant roots growing into cracks and expanding, animals digging can break apart rocks
• Exfoliation:

  • Overlying layers of rock are removed, pressure is released, rocks below expand and break along curved joints, peeling off like layers of an onion
  • Can also result from temperature changes
• Oxidation:

  • Oxygen combines with minerals in rocks, forming new substances like iron oxide (rust)
• Hydrolysis:

  • Chemical breakdown of rocks/minerals when combined with water, leading to the breakdown of rock
• Carbonation:

  • CO2 dissolved in water produces carbonic acid which reacts with & dissolves some rocks and minerals
• Organism:

  • Acids form from the decay of dead organisms, lichens make acids that can dissolve rock
• Air pollution can increase chemical weathering by making rainwater & precipitation more acidic (acid rain/acid precipitation)
• Factors affecting weathering rate:

  • Mineral composition
  • Climate
  • Surface area
• Erosion is the transport of sediments, while deposition is the dropping of sediments
• Soil:

  • Made out of minerals, organic matter, water, and air
  • Forms through the weathering of rocks and the accumulation of organic material
  • Factors affecting soil formation include climate, organisms, relief, parent material, and time
• Weathering is the breakdown of rock into sediments due to processes at the Earth’s surface
• Physical weathering changes only size & shape of rock, composition remains the same
• Chemical weathering involves chemical reactions that change the composition of rock
• Physical weathering processes:

  • Frost wedging:
  • Water gets into cracks, freezes & expands, causing rock to break
  • Results in potholes, common in New York and freezing temps
  • Abrasion:
  • Rocks rub and bounce against each other, breaking into smaller pieces
  • Wind, moving water, and glaciers/ice can cause abrasion
  • Organisms:
  • Plant roots growing into cracks and expanding them
  • Animals digging can break apart rocks
  • Exfoliation:
  • Overlying layers of rock are removed, pressure is released, rocks below expand and break along curved joints
  • Can also result from temperature changes
• Chemical weathering processes:

  • Oxidation:
  • Oxygen combines with minerals in rocks
  • Results in the formation of iron oxide (rust)
  • Hydrolysis:
  • Chemical breakdown of rocks/minerals when combined with water
  • Results in the breakdown of rock and formation of new substances
  • Carbonation:
  • CO2 dissolved in water produces carbonic acid which reacts with and dissolves some rocks and minerals
  • Results in the dissolution of rocks and minerals
  • Organism:
  • Acids form from the decay of dead organisms
  • Lichens make acids that can dissolve rock
• Factors affecting weathering rate:

  • Mineral composition: harder rocks are more resistant to weathering
  • Climate: arid/dry weather slows weathering, cold and wet weather speeds up physical weathering, warm and wet weather speeds up chemical weathering
  • Surface area: smaller pieces weather faster than bigger pieces
• Soil:

  • A mixture of rocks, air, water, and organic matter
  • Formed from the breakdown of rocks and organic matter
  • Factors affecting soil formation: climate affects mineral content and organic matter
• Soil profile layers:

  • Humus
  • Topsoil
  • Subsoil
  • Parent material
  • Bedrock
• Types of soil:

  • Residual soil: parent material is the local bedrock beneath the soil
  • Transported soil: formed from parent material in a different area and brought into a new area by wind, water, or ice
• Erosion and deposition:

  • Erosion is the transport of sediments, deposition is the dropping of sediments
  • Major agents of erosion/deposition: wind, gravity, waves, running water
• Sorting & shape of eroded sediments:

  • Sorted sediments are larger, more dense, and rounder, associated with water & wind
  • Unsorted sediments are mixed up, associated with gravity and ice
• Mass movements:

  • Downhill transportation of rock or sediment caused directly by gravity
  • Sediments are angular & unsorted
  • Topography depends on the balance between constructive and destructive processes
• Glaciers/ice erosion features:

  • Striations
  • U shaped valley
  • Finger lakes
  • Great Lakes
• Glaciers/ice deposition features:

  • Moraine
  • Drumlin
  • Outwash plain
  • Esker
  • Kame
  • Erratic
  • Kettle
• Ocean waves erosion features:

  • Beach drift due to longshore current
• Ocean waves deposition features:

  • Sand bar
  • Barrier island
• Ocean waves erosion control measures:

  • Jetty
  • Groin
• Chemical weathering involves reactions between minerals in rocks and water or air to form new compounds.
• wind erosion is affected by..?

  velocity and location
• in wind erosion, faster winds carry larger sediments and increase rate of erosion
• wind erosion mostly happens in arid/dry climates along the cost
• identify the physical weathering process: water gets into cracks, freezes and expands, melts, until rock breaks : Frost wedging
• what physical weathering process causes potholes, common in NY, and occurs in above/below freezing temps?


  frost wedging