Rock Characteristics

Rock Characteristics

1. Granite

   • Impermeable-doesn't let water pass through
   • Tors-formed by freeze-thaw and hydrolysis
   • Peat bogs-areas of standing water
   • V-shaped valleys-steep due to resistance of rock
   • Land higher altitude-resistance of rock
   • Igneous rock

2. Clay

   • Sedimentary rock
   • Vales found at foot of chalk escarpments
   • Collapses easily when wet
   • Impermeable-many surface streams
   • Not easily eroded
   • High in nutrient

3. Chalk

   • Sedimentary rock-calcium carbonate
   • Porous and Pervious
   • Dry valleys
   • Eroded by solution
   • Thin soils
   • steep cliffs at coast and gentle hills inland
   • Chalk beds are good natural aquifers

4. Limestone

   • Sedimentary rock-calcium carbonate
   • Dissolves in carbonic acid-creates range of distinctie landforms
   • Joints-vertical
   • Bedding planes-horizontal
   • Pervious-lets water/liquids penetrate it
   • Landforms
     • Swallow/Sink holes-acidic rainwater dissolves and widens joint, surface streams disappear underground.
     • Limestone pavements-limestone exposed at surface due to erosion, joints widen creating grikes and blocks are clints
     • Dry valleys-eroded by fast flowing surface streams at end of ice age
     • Gorges-roof of underground cave system collapses due to limestone solution, leaves stream flowing at base of deep narrow valley
     • Caves-stream flowing down swallowhole dissolves large area underground, stalactites from ceiling, stalagmites from floor