S-Cool Revision Summary

S-Cool Revision Summary

  • Igneous Rocks are Fire formed. They originate from the magma in the mantle of the Earth. They can be extrusive or intrusive.
  • Over millions of years the actions of rivers, glaciers and the wind produce large amounts of small particles called sediments. These accumulated on sea floors in layers, and due to the pressure of material above they were compressed to form sedimentary rocks.
  • Rocks which have been changed in shape or form, usually by heat or pressure, are called metamorphic rocks. They begin as either igneous or sedimentary rocks.
  • Igneous, sedimentary and metamorphic rocks together form the rock cycle.
  • Freeze-thaw occurs when water enters cracks in the rock during the day. Overnight the temperature drops and the water freezes. As it freezes, it expands, cracking the rock.
  • In hot, dry climates exfoliation occurs due to the heating and cooling of the rock.
  • Hydrolysis attacks rocks which include feldspar crystals. It dissolves them and disintegrates the rock.
  • Carbonation occurs when Calcium carbonate in the rocks reacts with acidic water and dissolves leaving behind calcium bicarbonate.
  • It is a hard, crystalline rock, which is very resistant to erosion.
  • The main processes which affect it are freeze-thaw and hydrolysis.
  • A good example area to use in Great Britain is Dartmoor.
  • The main granite landforms are tors.
  • Because granite is impermeable, and the soil is poor, areas such as Dartmoor are ideal sites for reservoirs.
  • Historically granite areas were mined, especially in the South-West, for things such as copper, tin and arsenic.
  • Tourism is increasingly becoming important in granite areas.
  • Formed from the remains of organic matter, usually seashells and plants. It was formed under the sea 220-280 million years ago.
  • The main processes which affect it are carbonation and solution.
  • The two best areas of carboniferous limestone in Britain are the Yorkshire Dales and the Peak District.
  • Carboniferous limestone produces distinctive karst scenery.
  • The tourist industry is a very important source of income to limestone areas.
  • Limestone is an excellent building stone, and has been used in some very well known buildings, such as the Houses of Parliament.
  • It is used as an industrial cleanser, farmers use it as fertiliser and it forms an important ingredient in cement making.
  • Chalk is an example of a porous rock, as it has pore spaces, which can store water. It does not have joints and bedding planes like carboniferous limestone.
  • Clay is porous, but becomes impermeable when wet, as the particles expand and fill the pore spaces.
  • The main areas of chalk and clay in this country are in the South and East of the country. Places like the North and South Downs are good examples.
  • Chalk and Clay landforms centre around escarpments and include dry valleys, bournes and clay vales.
  • Clay is very fertile, but must be drained first. Once that has been done farming includes dairying, sheep grazing, and some arable farming. On the chalk escarpments the main agriculture is sheep grazing.
  • Chalk is a main ingredient in cement making, and is quarried for that purpose. Clay can be used in pottery.
  • Quarrying is one of the biggest industries in the areas where granite, limestone, chalk and clay are found.
  • Quarries provide much needed employment.
  • The increased income means that more money is likely to be put into the local economy.
  • Noise pollution from the blasting needed to extract rock.
  • Noise and dust pollution from the many heavy lorries that will be travelling to and from the quarry every day.
  • Wildlife habitats are initially lost when the quarry opens.
  • Possible solutions include using trains rather than lorries, using trees to screen off the quarry and landscaping the quarry once production has ceased.