Coasts

• What is coastal recession dependent on?

  Bedrock lithology
• What does lithology refer to?

  Physical properties of rock, like hardness
• How does lithology affect coastal recession?

  Different rocks erode at different rates
• How much do igneous rocks erode per year?

  1 mm to 5 mm
• Why are igneous rocks highly resistant to erosion?

  They have a hard, crystalline structure
• What forms igneous rocks?

  Cooling magma
• How much do metamorphic rocks erode per year?

  1 mm to 10 cm
• What makes metamorphic rocks more prone to folding?

  Crystals aligned in one direction
• How are metamorphic rocks formed?

  Intense heat and pressure on sedimentary rocks
• How much do sedimentary rocks erode per year?

  2 cm to 6 cm
• What are clastic sedimentary rocks made of?

  Fragments of other rocks
• Why are sedimentary rocks vulnerable to erosion?

  They have many fractures and are porous
• What creates some types of sedimentary rocks?

  Layers of remains of dead life
• What are unconsolidated materials?

  Loose rock layers not cemented together
• How fast can coastlines of unconsolidated material erode?

  Up to 10 m a year
• What is coastal recession?

  Movement of the coastline inland due to erosion
• What is the most abundant igneous rock?

  Basalt
• What is the significance of Fingal's Cave?

  It has basalt rock formations
• How does lithological structure affect coastal recession?

  Complex cliff profiles lead to varied erosion
• What happens to cliffs with less resistant rock at the base?

  They are more likely to experience undercutting
• What is the effect of multiple folds in rock strata?

  They create cracks and fractures
• What do impermeable rocks create?

  Greater amounts of surface runoff
• What is pore water pressure?

  Pressure from water in permeable rocks
• How can permeable rocks lead to slumping?

  They gain mass from rainwater
• What is chemical weathering?

  Rocks chemically react with seawater
• How does geological structure influence coastal morphology?

  Different rock types affect landforms
• What is deformation in geology?

  Bending and crumpling of strata
• What do joints and bedding planes allow?

  Water to seep in and cause weathering
• What happens when wave-cut notches become too large?

  They can cause a rockfall
• What is the effect of strata dipping towards the sea?

  Waves can undercut the more resistant rock
• What occurs when strata dip away from the sea?

  There is no undercutting, making cliffs stable
• What are micro-features in cliff profiles?

  Small-scale features caused by erosion
• What are the characteristics of a discordant coastline?

  • Alternating hard and soft rock bands
  • Hard rocks form headlands
  • Soft rocks erode to form bays
• How do headlands and bays form on a discordant coastline?

  Less resistant rock erodes faster, forming bays
• What happens to wave energy at headlands?

  It increases, leading to higher erosion
• What are the characteristics of a concordant coastline?

  • Bands of rock run parallel to shoreline
  • Resistant outer rock protects softer inner rock
  • Coves can form as softer rock erodes
• What forms a Dalmatian coastline?

  Flooded valleys parallel to the coast
• What are the features of a Haff coastline?

  • Deposits of sand run parallel to coastline
  • Offshore bars create lagoons
  • Formed by sediment accumulation
• What is the sediment budget?

  Difference between sediment entering and leaving
• What indicates a positive sediment budget?

  More sediment enters than leaves