1. Igneous Rocks
Recap of last lesson:

2. Igneous Rocks Recap of last lesson:
Igneous Rocks are formed from the cooling of molten rock.

3. Igneous Rocks Recap of last lesson:
Igneous Rocks are formed from the cooling of molten rock.
Igneous Rocks formed above the ground are called Extrusive Rocks.

4. Igneous Rocks Recap of last lesson:
Igneous Rocks are formed from the cooling of molten rock.
Igneous Rocks formed above the ground are called Extrusive Rocks.
Igneous Rocks formed below the ground are called Intrusive Rocks.

5. Igneous Rocks Recap of last lesson:
Igneous Rocks are formed from the cooling of molten rock.
Igneous Rocks formed above the ground are called Extrusive Rocks.
Igneous Rocks formed below the ground are called Intrusive Rocks.
Extrusive Rocks cool quickly allowing only small crystals to form.

6. Igneous Rocks Recap of last lesson:
Igneous Rocks are formed from the cooling of molten rock.
Igneous Rocks formed above the ground are called Extrusive Rocks.
Igneous Rocks formed below the ground are called Intrusive Rocks.
Extrusive Rocks cool quickly allowing only small crystals to form.
Intrusive Rocks cool slowly allowing large crystals to form.

7. Igneous Rocks Recap of last lesson:
Igneous Rocks are formed from the cooling of molten rock.
Igneous Rocks formed above the ground are called Extrusive Rocks.
Igneous Rocks formed below the ground are called Intrusive Rocks.
Extrusive Rocks cool quickly allowing only small crystals to form.
Intrusive Rocks cool slowly allowing large crystals to form.
Obsidian, pumice and basalt are examples of extrusive igneous rocks.

8. Igneous Rocks Recap of last lesson:
Igneous Rocks are formed from the cooling of molten rock.
Igneous Rocks formed above the ground are called Extrusive Rocks.
Igneous Rocks formed below the ground are called Intrusive Rocks.
Extrusive Rocks cool quickly allowing only small crystals to form.
Intrusive Rocks cool slowly allowing large crystals to form.
Obsidian, pumice and basalt are examples of extrusive igneous rocks.
Granite and gabbro are examples of intrusive igneous rocks.

9. There exist three different types of rocks:
Igneous Rocks
Sedimentary Rocks
Metamorphic Rocks

10. Sedimentary Rocks

11. Rocks that are formed from the particles that comprise sediments are called sedimentary rocks

12. Rocks that are formed from the particles that comprise sediments are called sedimentary rocks
Grains or sediments are squeezed and cemented together to form solid rock

13. Rocks that are formed from the particles that comprise sediments are called sedimentary rocks
Grains or sediments are squeezed and cemented together to form solid rock
Sediment particles vary in size from fine silt, to sands, to pebbles and larger rocks

14. Rocks that are formed from the particles that comprise sediments are called sedimentary rocks
Grains or sediments are squeezed and cemented together to form solid rock
Sediment particles vary in size from fine silt, to sands, to pebbles and larger rocks
Different sediments lead to different types of sedimentary rocks, however almost all are formed by the same processes

15. Fine grain sediments such as silt results in a flaky rock called shale.
Sand gives rise to sandstone.
Mixture of sediments and rock of different sizes, cemented together is called conglomerate.

16. Discussion: 3 mins In pairs, briefly discuss the following questions:
How do large rocks become sediments?
Where would you most likely expect sediments to gather and consequently where would you expect them to form?

17. These sediments are formed from the weathering of rock by two processes:

18. These sediments are formed from the weathering of rock by two processes:
Physical weathering: force of wind, rain, waves, glaciers and expanding ice fracture and wear away pieces of rock.

19. These sediments are formed from the weathering of rock by two processes:
Physical weathering: force of wind, rain, waves, glaciers and expanding ice fracture and wear away pieces of rock.
Chemical weathering: minerals in the rock react with chemicals dissolved in rainwater breaking down or weakening the rock.

20. These particles are washed into waterways such as rivers, that feed into lakes or the sea where the particles are deposited.
Over time these particles build up to form layers; this process is called sedimentation.

21. As these layers build, the weight of the material above squeezes the sediment particles close together.
This process is called compaction.

22. This compression squeezes out water from between the particles, leaving dissolved minerals behind that bind the particles to form solid rock.
This process is called cementation.

24. These processes are slow.

25. These processes are slow.
The formation of sedimentary rocks can take millions of years.

26. These processes are slow.
The formation of sedimentary rocks can take millions of years.
Often in large bodies of sedimentary rock distinct layers can be seen, each laid down at a different time.

27. The remains of plants and animals can also form sediments that in turn form sedimentary rocks:
Formed from the remains of dead plants. Coal can often take on a woody appearance.
Coal
Formed from the remains of dead sea organisms such as shellfish and coral.
Limestone

28. Rock Examination: In your books, record details about: the texture
Around the room there will be several different sedimentary rocks (those mentioned today). In groups of 2-3, move around to examine each rock.
In your books, record details about:
the texture
the type of sediment that would have formed this rock
which rock it is