StudyNotes.ie

There are 3 types of rocks.

Igneous 

  • Igneous is made when magma rises from the mantle.
  • Under the surface ,it slowly cools and hardens.
  • This is known as intrusive rocks .
  • Example Granite .
  • Above the surface , it hits the cool air and hardens .
  • This is known  as extrusive rock. Example Basalt.

The next rock is called Sedimentary  rock .

  • Rocks on the earth's surface  are  worn down over time .
  • Some broken  pieces  of rock make their way down to the sea.
  • They become compressed and cemented and mixed with dead Sea creatures .
  • They form layers .
  • Example Limestone ,Sandstone 

The last rock types is called Metamorphic rock .

  • Formed when igneous and sedimentary  rrocks are put under great heat and pressure. 
  • This changes the rock into a new harder rock .
  • Example .Marble,Quartzite.