1. Igneous, Sedimentary & Metamorphic Rocks
...and the Rock Cycle
PowerPoint Notes created by S. Koziol
Date : 9/7/2013 Revised : ?/?/??

2. Igneous Rocks
Compare and contrast intrusive and extrusive igneous rocks.
Describe the composition of magma
Discuss the factors that affect how rocks melt and crystallize.
Classify different types and textures of igneous rocks.
Recognize the effects of cooling rates on grain sizes of igneous rocks.
Describe some uses of igneous rocks.

3. Igneous - crystallization
Igneous rocks are formed when magma crystallizes.

4. Lava
Lava is magma that flows out onto Earth's surface.

5. Melting Point
Factors that affect a rock’s melting point include pressure and water content.

6. Melting Point - continued
As the water content of rock increases, the melting point decreases.

7. Intrusive
Igneous rocks that cool slowly beneath Earth’s crust are intrusive.

8. Grain-size
Extrusive rocks, which cool more rapidly than intrusive rocks, are generally more finely grained.

9. Coarse-Grained Intrusive igneous rocks form coarse-grained rocks.
Diorite is a coarse-grained, intrusive igneous rock that is intermediate in composition between granite and gabbro.

10. Extrusive
Igneous rocks that cool quickly on Earth’s surface are extrusive.
Obsidian is an igneous rock that forms when molten rock material cools so rapidly that atoms are unable to arrange themselves into a crystalline structure. Aka volcanic glass

11. Igneous Classification
Extrusive igneous rocks
Intrusive igneous rocks
Both terms describe an igneous rock which is classified based on how it is formed.
Coarse-grained igneous rocks that cool slowly beneath Earth’s surface are intrusive igneous rocks.
Fine-grained rocks that cool quickly on Earth’s surface are extrusive igneous rocks.

12. Composition Classification
Igneous rocks are classified as felsic, mafic, and intermediate.
Stop Point

13. Main 3
Felsic rocks are light-colored, have high silica content, and contain quartz and feldspars.
Mafic rocks are dark-colored, have low silica content, and are rich in iron and magnesium.
Intermediate rocks
lie between felsic
and mafic rocks in
silica and iron
content.

14. Porphyritic texture
A rock that has grains of two different sizes has porphyritic texture.

15. Felsic
Felsic rock is light-colored rock such as granite that has high silica content.
Half Dome at Yosemite National Park is composed of granodiorite

16. Mafic
Mafic rock is dark-colored rock such as gabbro that is rich in iron and magnesium.

17. Ultramafic
Ultramafic rock is rock that is very high in iron and magnesium.
Ultramafic pillow-lavas
(YOUTUBE Link)

18. Bowen’s
A model that illustrates the predictable patterns of mineral formation from cooling magma is Bowen's reaction series.

19. Ores & Gems
Valuable ore deposits and gem crystals are often associated with igneous intrusions.

20. Kimberlites Kimberlite is course-grained rocks associated with
diamonds in igneous outcrops, named after the
area of S. Africa where they were first discovered.

21. Sequence the Formation of Sedimentary Rocks.
Explain the formation and classification of clastic sediments.
Describe features of Sedimentary Rocks.
Describe the types of clastic Sedimentary Rocks.
Explain how chemical sedimentary rocks form.
Describe organic Sedimentary Rocks.
Recognize the importance of Sedimentary Rocks.

22. Sediments
Much of Earth’s surface is covered not by solid rock, but by sediments.

23. W Mass Bedrock

24. Actual outcrops are a rare feature.
W Mass Sediments
Alluvial fan deposits
Actual outcrops are a rare feature.

25. Sediments (continued)
Sediments are
pieces of solid
Material
deposited on
Earth’s surface.

26. Deposition
Deposition is the process of sediments being laid down on the ground or sinking to the bottom of water.

27. Lithification
Lithification is the physical and chemical processes that compact and transform sediments into sedimentary rocks.

28. Permineralization
During lithification, parts of an organism are replaced by minerals and turned into rock.

29. Erosion
Landslides, moving water, wind, and glaciers cause erosion of surface materials.

30. Sorted Deposits
Sorted deposits are characteristic of sediments transported by water and wind.

31. Weathering Effects
Weathering of rock produces worn surfaces and rounded corners that are characteristic of some clastic sediment particles.

32. Clastic Sediments
Clastic sediment particles have worn surfaces and rounded corners.

33. Breccia
Breccia sedimentary rock is coarse-grained with angular fragments.

34. Bedding
The primary feature of sedimentary rocks is horizontal layering called bedding. (repetitive laying)

35. Graded Bedding
Graded bedding has the heaviest and coarsest material is on the bottom.

36. Graded Bedding (continued)
Graded bedding is produce in marine landslides.

37. Unsorted Bedding
Landslide and glaciers produce unsorted deposition.

38. Cross bedding
Cross bedding is inclined sediment layers that migrate forward across a horizontal surface.

39. Ripple Marks
One-way wave actions of wind or water produce asymmetrical ripple marks.

40. Dry Land Evidence
The presence of dry land in past environments allow for the deposition of four-footed animal fossils.

41. Porosity
Porosity is the percentage of open spaces between grains in a rock.

42. Sandstone vs Shale Porosity
Sandstone is porous. When its pore spaces are connected to one another, fluids can move through the sandstone, making sandstone layers valuable as underground reservoirs. However, shale has low porosity, meaning that the pore spaces are small. This hinders the movement of fluids.

43. Evaporite
Evaporite are layers of chemical sedimentary rocks that form from precipitated minerals.

44. Compare & Contrast
Both are sedimentary rocks which are classified by method of formation.
Evaporites form when water evaporates from mineral-rich solutions, causing the minerals to precipitate out of the solutions.
Conglomerates form from deposits of loose sediments on Earth’s surface.

45. Limestone
Limestone is an organic sedimentary rock, and is the most abundant organic sedimentary rock on Earth. It is calcite-rich (CaCO3).

46. Weathering
If weathering did not occur, sedimentary rock would not form. Its absence would likely affect the formation of igneous and metamorphic rock as well.

47. Ancient Conditions
Some sedimentary rocks contain sedimentary structures that indicate the location and direction of flow of ancient rivers, the wave or wind direction over lakes and deserts, and ancient shoreline positions.

48. Section 3 Metamorphic Rocks & the Rock Cycle
Compare and contrast the different types and causes of metamorphism.
Distinguish among metamorphic textures.
Explain how mineral and compositional changes occur during regional metamorphism.
Understand how rocks change from one type to another in the rock cycle.

49. Two Primary Types of Metamorphism
Regional this type occurs over large areas, generally during mountain building.
Contact this type is limited to contacts with igneous bodies.

50. Regional Metamorphism
Regional metamorphism rocks are changed over a wide area by deep burial and heating associated with the large-scale forces of plate tectonics.

51. Contact Metamorphism
Contact metamorphism results when rocks come in contact with molten rocks such as those in an igneous intrusion.

52. Metamorphic - Foliated
Foliated metamorphic rocks are composed of minerals with crystals that have their long axes perpendicular to pressure, associated with regional metamorphism.

53. Nonfoliated metamorphic
Nonfoliated metamorphic rocks are composed of minerals that form blocky crystal shapes, associated with contact metamorphism.

54. Examples
The metamorphism of limestone results in the formation of marble.

55. Foliated vs. Non-foliated
Both are textures of metamorphic rocks.
Garnet Schist
Foliated rocks have distinct banding or layers that formed perpendicular to pressure.
Quartzite
Nonfoliated rocks are crystals with blocky shapes and do not have banding.

56. Sedimentary vs. Metamorphic
Both are types of rocks classified by method of formation.
Sedimentary rocks form when sediments are cemented together.
Metamorphic rocks form when high temperature and pressure cause the texture, mineralogy, or chemical composition of a rock to change without melting it.

57. Rock cycle
The Rock cycle is the continuous changing and remaking of rocks.

58. Rock Cycle Worksheet Rock Cycle Multimedia Assignment

59. Earth’s Surface Graphing exercise