There are 3 types of rocks.
- 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.