1. What things are rocks used for?

17. Rocks

18. What are rocks?
Rock is a compact mass of mineral matter

19. Types of Rocks
Metamorphic Rocks
Igneous Rocks
Sedimentary Rocks

20. Igneous rocks

21. Igneous Rocks What are They?
Fire Rocks
Formed underground by trapped, cooled magma
Formed above ground when volcanoes erupt and magma cools

22. Types of Igneous Rocks
Scoria
Granite
Pumice
Obsidian

23. Igneous Rocks
These are rocks that are formed by the cooling and solidification of molten rock (magma) from beneath the earth’s crust. They are normally crystalline. Lava forms igneous rock. Granite and basalt are the main examples.

24. Types of Sedimentary Rocks
Sandstone
Limestone
Gypsum
Conglomerate
Shale

26. Sedimentary Rocks How They are Made
Wind and water break down the earth
Bits of earth settle in lakes and rivers
Layers are formed and build up
Pressure and time turn the layers to rock

27. Sedimentary rock
This is a group of rocks that is formed from sediments – they
Have accumulated overlong periods of time, and usually under water
Have a layered structure, and are described as being stratified
Often contain fossils
Sandstone, limestone, chalk and coal are all examples

28. Metamorphic Rocks What are They?
Rocks that have changed
They were once igneous or sedimentary
Pressure and heat changed the rocks

29. Types of Metamorphic Rocks
Schist
Gneiss

30. Metamorphic rock
These are a type of rock which has been altered from an earlier one by heat and/or pressure.
For example – marble is a metamorphic rock which was once limestone, a sedimentary rock.
Metamorphic rocks are tough and resistant to erosion and are often used as building materials eg Slate

32. Rocks

33. What is weathering? What is Erosion?

34. Weathering is . . . Erosion is . . .
Weathering is the breakdown of rocks due to the weather
Erosion is the breakdown of rock due to their contact with water, ice, heat or anything which rubs against the rock