rates of recession

• define rate of recession

  the speed at which a coastline is moving inland
• what are the 3 rock types


  igneous, metamorphic, sedimentary
• how are igneous rocks formed


  from solidified lava or magma
• what is the composition of igneous rocks

  interlocking crystals
• what joints are found in igneous rock

  cooling joints
• how are metamorphic rocks formed

  by recrystalisation of sedimentary or igneous rocks through heat and pressure
• what is the structural composition of metamorphic rocks


  crystals often oriented in the same direction (not interlocking) which means they are weaker than igneous
• how are sedimentary rocks formed


  compaction and cementation of deposited material
• features of sedimentary rocks


  bedding planes + heavily jointed as a result of compaction and pressure release
• what is solid geology (solid rock) often covered by

  unconsolidated material
• where might unconsolidated material come from

  rivers= alluvium

  glaciers= boulderclay / till

  wind= loess
• rates of erosion for rock types

  igneous = 0.1 cm p.a (slow)

  metamorphic = 1cm p.a (slow)

  sedimentary = old, 1cm p.a (slow)

  or

  sedimentary = young, 10cm p.a (fast)

  unconsolidated = very fast, eg happisburgh 1m p.a
• define rate of recession

  the speed at which a coastline is moving inland
• what are the 3 rock types

  igneous, metamorphic, sedimentary
• how are igneous rocks formed


  from solidified lava or magma
• what is the composition of igneous rocks

  interlocking crystals
• what joints are found in igneous rock

  cooling joints
• how are metamorphic rocks formed

  by recrystalisation of sedimentary or igneous rocks through heat and pressure
• what is the structural composition of metamorphic rocks


  crystals often oriented in the same direction (not interlocking) which means they are weaker than igneous
• how are sedimentary rocks formed


  compaction and cementation of deposited material
• features of sedimentary rocks


  bedding planes + heavily jointed as a result of compaction and pressure release
• what is solid geology (solid rock) often covered by

  unconsolidated material
• where might unconsolidated material come from

  rivers= alluvium

  glaciers= boulderclay / till

  wind= loess
• rates of erosion for rock types

  igneous = 0.1 cm p.a (slow)

  metamorphic = 1cm p.a (slow)

  sedimentary = old, 1cm p.a (slow)

  or

  sedimentary = young, 10cm p.a (fast)

  unconsolidated = very fast, eg happisburgh 1m p.a