1. How did all of these rocks get here?
The Story of Rocks
How did all of these
rocks get here?

2. Rock types Rock types are based on the way the rocks formed! Igneous
Sedimentary
Metamorphic

3. Igneous These rocks are formed from molten or liquid rock.
Magma = liquid rock inside the Earth
Lava = liquid rock on the surface.

4. Sedimentary
These rocks are made of small fragments of rock cemented together
The small fragments are broken down from larger rocks by wind, water, and other forces and carried away.
Later they are deposited, buried deeper and deeper until they are compacted into rock.

5. Metamorphic These rocks start as igneous or sedimentary rocks.
Rocks are changed by:
1) heat
2) pressure
3) chemical processes

8. Rock Cycle

9. Rock Cycle

14. Igneous Rocks

15. Igneous Rocks
The main property of igneous rocks that allows us to identify which type of igneous rock that we have is – Texture
The texture is based on how large the crystals.
Crystal size depends on how fast the rock cooled (i.e. cooling rate)

16. Igneous Rocks

17. Igneous Rocks

18. Igneous Rocks

19. Igneous Rocks

20. Igneous Rocks

21. Igneous Rocks

22. Igneous Rocks

24. Sedimentary Rocks

25. Sedimentary Rocks
The main property that allows us to group sedimentary rocks is the source of sediments.
Sediments can be:
1. Clastic
2. Chemical
3. Organic

26. Sedimentary Rocks
Clastic – These sediments are composed of fragments that can be up to a meter in diameter or so small that the fragments cannot be seen with the naked eye.

27. Sedimentary Rocks
Chemical – These fragments were dissolved in water and usually form at the bottoms of rivers, lakes, seas, and oceans

28. Sedimentary Rocks
Organic – These fragments are from organic material like animals and plants

29. Sedimentary Rocks Common sedimentary features:
Stratification (layering)
Ripple marks (from waves)
Cross bedding (different direction of beds)
Mud cracks (dried mud)
fossils (lithified animals and plants)
concretions

30. Sedimentary Rocks
Stratification

31. Sedimentary Rocks
Ripple marks

32. Sedimentary Rocks
Cross bedding

33. Sedimentary Rocks
Mud Cracks

34. Sedimentary Rocks
Fossils

36. Metamorphic Rocks

37. Metamorphic Rocks
Metamorphic rocks began their life as an igneous or sedimentary rock but underwent a physical change to become a new type of rock.
What causes the changes?
1. Heat
2 Pressure
3. Chemicals

38. Metamorphic Rocks There are two basic types of metamorphism:
1. Contact Metamorphism
2. Regional metamorphism

39. Metamorphic Rocks Contact Metamorphism
Occurs when rocks near a magma chamber are exposed to high levels of heat but not melted

40. Regional Metamorphism
Metamorphic Rocks
Regional Metamorphism
Occurs when rocks are exposed to tectonic pressure or heat.

41. Metamorphic Rocks

42. Metamorphic Rocks
How do we classify metamorphic rocks since they have a wide range of compositions and origins?
Foliation!!
Definition: Visible parallel bands
(not layers)
Metamorphic rocks are foliated or unfoliated

43. Metamorphic Rocks
Foliation occurs because the mineral grains are squished by the intense heat or pressure

44. Metamorphic Rocks

45. Metamorphic Rocks

46. Metamorphic Rocks
Unfoliated