1. Today’s lesson
Three main rock types

2. Three main rock types
Igneous

3. Three main rock types
Sedimentary

4. Three main rock types
Metamorphic

5. Igneous rocks
From the latin “ignis” meaning fire

6. Igneous rocks Formed by the cooling of lava or magma
What’s the difference?
Formed by the cooling of lava or magma

7. Igneous rocks
Made from crystals

8. Igneous rocks
Quick cooling forms small crystals, slow cooling forms large crystals

9. Igneous rocks
Basalt is formed by quickly cooling lava

10. Igneous rocks
Pumice is formed from lava that contains a lot of gas. It can float!

11. Igneous rocks
Obsidian is like dark glass formed when molten silica cools quickly!

12. Igneous rocks
Granite is made from magma that cools slowly underground

13. Sedimentary rocks

14. Sedimentary rocks
Sediments like sand and mud build up at the bottom of oceans and rivers

15. Sedimentary rocks
Over millions of years pressure from successive layers forms these into sedimentary rocks

16. Sedimentary rocks
Layers!

17. Sedimentary rocks
Animals and plants can be trapped in the sediments and can form fossils

18. Sedimentary rocks
Sandstone is made from sand grains stuck together

19. Sedimentary rocks
Limestone is made from the mineral calcite which came from the beds of evaporated seas and lakes and from sea animal shells.

20. Sedimentary rocks
Conglomerate rocks are made up of large sediments like pebbles. The sediment is cemented together with dissolved minerals.

21. Sedimentary rocks
Shale are formed from clay and mud that is compacted together by pressure.

22. Metamorphic rocks

23. Metamorphic rocks
Metamorphic rocks are rocks that have "morphed" into another kind of rock.

24. Metamorphic rocks
These rocks were once igneous or sedimentary rocks. The rocks are under tons of pressure, which causes heat build up, and this causes them to change.

25. Metamorphic rocks
These often also contain thin layers and crystals but are much harder than sedimentary rocks

26. Metamorphic rocks
Marble is limestone that has been metamorphised

27. Metamorphic rocks
Slate is metamorphised shale

28. Metamorphic rocks
Anthracite coal

29. Brain-map
Mr Porter is now going to put these slides on a loop so you can brain map them!