Geology - Rock Cycle
 

Should know the how to recognise the rock types below and understand how they were made (if you can relate their properties to how they were made that would be brilliant!).......

Pass the cursor over the writing for further information.  Click on the hyperlinks to see pictures of the rocks.

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This is how all rocks are broken down! It could be by the action of the river rolling the rocks, freeze & thaw breaking up the rocks, heating & cooling with the seasons, attack by acid rain or the roots of trees and plants. .

Volcanic

glass

Granite

This usually by rivers and streams that lead down to the sea.

 Igneous rocks made here! As the molten lava cools, the crystals grow. The speed of cooling leads to smaller or bigger crystals being formed.
  Conglomerate Sandstone

Coal

Limestone

 Metamorohic rocks made here! The heat and pressure of the lava as it forces its way to the surface - leads to changes in the surrounding rocks. In general rocks become harder. Limestone will change to marble. Mudstone or shale becomes slate and so on!

Schist

Mudstone

Siltstone

Marble

Sedimentary rocks are made here! They are either formed when loose sediment accumulates on top, everything gets squashed into rock or other minerals seep into the sediment and glues the sand and pebbles together.

Slate

Gneiss

 

 
You need to be able to recognise the different rock types: 

Igneous Rock
  • these do not have fossils
  • usually hard
  • have an interlocking crystalline structure

Metamorphic Rock
  • these may be able to split along a cleavage plane - ie., slate
  • they could be banded or streaked
  • will bubble if HCl is added - in this case it will be marble
  • they don't have fossils
  • they will look crystalline
  • they contain may look sparkly because of the mica they contain
  • they are usually very hard

Sedimentary Rock
  • these might contain fossils
  • usually these are quite soft and you maybe able to rub off grains from them
  • the grains that make up the rock are visibly separate
  • if you add HCl and the rock fizzes then Calcium Carbonate is present