1. Prentice Hall EARTH SCIENCE
Tarbuck Lutgens 

2. CALIFORNIA CONTENT STANDARD 3C
Students know how to explain the properties of rocks based on the physical and chemical conditions in which they formed, including plate tectonic processes.

3. CCSS.ELA-LITERACY.WHST.9-10.2.A
Introduce a topic and organize ideas, concepts, and information to make important connections and distinctions; include formatting (e.g., headings), graphics (e.g., figures, tables), and multimedia when useful to aiding comprehension.

4. Section Objectives Define the term “rock”.
Identify the 3 major types of rocks and explain how they differ.
Describe the rock cycle.
List the forces that power the Earth’s rock cycle.

5. Vocabulary Words ◆ rock ◆ igneous rock ◆ sedimentary rock
◆ metamorphic rock
◆ rock cycle
◆ magma
◆ lava
◆ weathering
◆ sediments

6. Rocks Chapter 3 TERM DEFINITION Rock
a. a solid mixture of one or more minerals
Igneous rock
b. rock that forms when magma or lava cools and hardens
Sedimentary rock
c. rock that forms when sediments become compacted and cemented
Metamorphic rock
d. any type of rock that changed by heat, pressure, or fluids
Rock cycle
e. the continuous process that causes rocks to change from one type to another
Magma
f. molten material that forms deep beneath Earth’s surface
Lava
g. magma that reaches the surface
Weathering
h. a process in which rocks are physically and chemically broken down by water, air, and living things
Sediments
i. bits of Earth materials

7. Chapter 3
Rocks
Section Objective
#1: Define the term rock.

8. Rocks
3.1 The Rock Cycle
Rocks are any solid mass or mixture of mineral or mineral-like matter occurring naturally as part of our planet. #1, RS a
Most rocks such as granite, occurs as a solid mixture of minerals. #2

9. Rock vs. minerals MINERALS ROCK
A characteristic of rock is that each of the component minerals retains its properties in mixture. #3
MINERALS
ROCK
The main difference between a rock and a mineral is that a mineral is the same substance all the way through -- while a rock is made up of different substances.
Elements make up minerals  Minerals make up rocks

10.  Magma is molten material that forms deep beneath the Earth’s surface
 Magma is molten material that forms deep beneath the Earth’s surface. RS f

11.  Lava is magma that reaches the surface. RS g

12.  Weathering is a process in which rocks are broken down by water, air, and living things. RS h

13.  Sediment is weathered piece of Earth elements; bits of Earth materials. RS i

14. #2: Identify the 3 major types of rocks and explain how they differ.
Chapter 3
Rocks
Section Objective
#2: Identify the 3 major types of rocks and explain how they differ.

15. The 3 Types of Rocks #5 Igneous rocks Sedimentary rocks
Metamorphic rocks
Rocks are grouped based on how they are formed.

16. 3.1 The Rock Cycle  Types of Rocks
1. Igneous rock is formed by the crystallization of molten magma.
Igneous means made from fire or heat.
Igneous rocks are the rocks that forms when magma or lava cools or hardens. RS b

17. Lava rock Igneous rocks can be classified as either Felsic or Mafic.
Mafic rocks are composed chiefly of dark colored materials containing iron and magnesium. Low in Silica
(55-65%)
Felsic rocks are composed mainly of light-colored materials -- such as mica, quartz and feldspar. High in Silica (65%+)
Felsic Igneous Rock

18. Other types of Lava Rock
Obsidian
Pumice
If it's light and full of air pockets, it's called pumice. Pumice exhibits a definite pyroclastic (volcanic) texture. It's the only rock that floats.
Coal is a combustible black or brownish-black sedimentary rock normally occurring in rock strata in layers or veins called coal beds or coal seams
If it's glassy, smooth and black, it's called obsidian.
Obsidian and pumice are volcanic rocks that do not have crystalline structure. Coal is considered a rock even though it consists of organic material. #4
Coal

19. 2. Sedimentary rock is a rock that is formed when sediments become compacted and cemented. RS c
When mountains are worn away due to erosion, little bits of rock (sediment) end up in the streams and rivers that flow down from the mountains. Over time, these sediments settle to the bottoms of the rivers and the lakes -- and the oceans they flow into. The most deposition (depositing of sediment) is likely to occur at the top of a steep slope in a streambed. As layers and layers of sediment build up, pressure on the protolith (the original material increases. This pressure turns the sediment into sedimentary rock.

20. Metamorphic Sedimentary Rocks
If this process takes place at low temperatures and pressures, it's called diagenesis. Higher temperatures and pressures cause metamorphosis (see below).
Metamorphic Sedimentary Rocks
Diagenesic Sedimentary Rocks
Sandstone, shale and jasper are sedimentary rocks.

21. Sedimentary rocks often have fossils in them
Sedimentary rocks often have fossils in them. That's because animals and plants died and got mixed up in the sediment. When this happens, sedimentary rocks turn into carbon -- which is how we get coal, oil, natural gas and petroleum. Rocks with lots of fossil shells in them were frequently created in shallow ocean bays.

22. 6 main kinds of sedimentary rock
Gypsym (common salt or Epsom salt found where sea water is precipitated or evaporates)
Limestone (made of calcium carbonate and/or microscopic shells; limestone contains many fossils)
Porphory Rock (jagged bits of rock cemented together)
Sandstone (grains of sand cemented together)
Conglomerate rock (rounded rocks pebbles and boulders - cemented together)
Shale (clay that has been hardened and turned into rock; shale often breaks apart in large, flat sections)

23. Metamorphic rocks are rocks that have changed or morphed.
3. Metamorphic rock is any type of rock that is changed by heat, pressure or fluids. RS d
Under extreme pressure and temperature conditions, sedimentary rock will change into metamorphic rock,
Metamorphic rocks were originally either igneous or sedimentary rocks that have changed because of the movement of the Earth's crust. High temperatures and pressures are involved -- much higher than the temperatures and pressures involved in the diagenesis that creates sedimentary rock.

24. There are two kinds of metamorphic rock: foliated and non-foliated.
Foliated metamorphic rock has different layers or banding. Slate is a good example. Slate is usually the product of regional metamorphosis. It is morphed from shale and splits apart into smooth slabs.
Non-foliated metamorphic rock is not layered.
Marble is a good example – it is morphed from limestone. The original minerals within the rock recrystallize into larger sizes and the atoms become more tightly packed together, increasing the density of the rock.
Quartzite
Marble

25. #3: Describe the rock cycle.
Chapter 3
Rocks
Section Objective
#3: Describe the rock cycle.

26. 3.1 The Rock Cycle The Rock Cycle
 the continous process that causes rocks to change from one type of rock to another. RS e

27. 3.1 The Rock Cycle
The Rock Cycle

28. The Rock Cycle Magma (molten rock)#6
Magma
(molten rock)
A. Magma forms when rock melts deep beneath the earth’s surface.
Any type of rock that is changed by heat, pressure or fluids become a metamorphic rock.
If an igneous rock remains deeply buried, strong forces and high temperature will change it into metamorphic rock. #7
H. Metamorphic rock
B. Igneous rock
G. When sediments are compacted and cemented, sedimentary rocks form.
C. When magma or lava cools and becomes solid, igneous rocks form.
F. Sedimentary rock
D. Sediment
E. Rocks at earth’s surface are broken down to smaller pieces called sediments.

29. 3.1 The Rock Cycle The 3Types of Rocks Types of rocks IGNEOUS ROCKS
Formed from the crystallization of magma
Types of rocks
May contain fossils
Formed /changed due to extreme heat and pressure
Formed when sediments become compacted and cemented
METAMORPHIC ROCKS
SEDIMENTARY ROCKS

30. #4: List the forces that power the Earth’s rock cycle.
Chapter 3
Rocks
Section Objective
#4: List the forces that power the Earth’s rock cycle.

31. 3.1 The Rock Cycle Energy That Drives the Rock Cycle
 Processes driven by heat from the Earth’s interior are responsible for forming both igneous rock and metamorphic rock.
 Weathering and the movement of weathered materials are external processes powered by energy from the sun.
 External processes produce sedimentary rocks.
 All the energy that drives the Earth’s rock cycle comes from the Earth’s interior and the sun.

32. 3.1 QUIZZ
1. What is a rock?
2. What are the three major types of rocks?
3. How do igneous, sedimentary, and
metamorphic rocks differ?
4. What is the rock cycle?
5. What powers Earth’s rock cycle?

33. 3.1 ANSWER
1. Most rocks are mixtures of one or more minerals. Some rocks, however, are not made of minerals.
2. igneous rocks, sedimentary rocks, and metamorphic rocks
3. Rocks differ in the way they form. Igneous rocks form when magma or lava cools and solidifies. Sedimentary rocks form when sediments become compacted and cemented. Metamorphic rocks form when existing rocks are changed by heat, pressure, or solutions.

34. 3.1 ANSWER
4. interactions among Earth’s water, air, and land which cause rocks to change
5. processes deep within Earth and energy
from the sun. Igneous rocks form when magma or lava cools and solidifies. Sedimentary rocks form when sediments become compacted and cemented.
Metamorphic rocks form when existing rocks are changed by heat, pressure, or solutions.

35. California Content Standard 3c
3.2 Igneous Rocks
California Content Standard 3c
Students know how to explain the properties of rocks based on the physical and chemical conditions in which they formed, including plate tectonic processes.

36. CCSS.ELA-LITERACY.WHST.9-10.2.A
Introduce a topic and organize ideas, concepts, and information to make important connections and distinctions; include formatting (e.g., headings), graphics (e.g., figures, tables), and multimedia when useful to aiding comprehension.

37. Section Objectives
Describe how igneous rocks form. What are the two types of igneous rocks?
Compare and contrast intrusive and extrusive igneous rocks. Give examples of each.
Explain how the rate of cooling affects the igneous rock’s texture.
Classify igneous rocks according to texture and composition.

38. Vocabulary Words ◆ intrusive igneous rock ◆ extrusive igneous rock
◆ porphyritic texture
◆ granitic composition
◆ basaltic composition
◆ andesitic composition
◆ ultramafic

39. 3.2 The Igneous Rock  How is it formed?
1. Igneous rock is formed by the crystallization of molten magma and lava..
Igneous means made from fire or heat.
Igneous rocks are the rocks that forms when magma or lava cools or hardens. RS b
***There are two types of igneous rocks:
Intrusive igneous rocks
Extrusive igneous rocks

40. Objective#1
Compare and contrast intrusive and extrusive igneous rocks.
rhyolite
granite

41. 3.2 Igneous Rocks A. Intrusive igneous rocks
Formation of Igneous Rocks RS
3.2 Igneous Rocks
Ignis – fire #1
Magma – melted material beneath the Earth surface #4
Lava – melted material at the Earth’s surface #5
A. Intrusive igneous rocks
1. are formed when magma hardens beneath Earth’s surface. #2
2. common example is granite
Granite is a light-colored igneous rock with grains large enough to be visible with the unaided eye.
B. Extrusive igneous rocks
1. are formed when lava hardens #3
2. common example is rhyolite
Rhyolite is a light-colored, fine-grained, extrusive igneous rock that typically contains quartz and feldspar minerals.

42. Compare and Contrast Igneous Rocks #8
INTRUSIVE
EXTRUSIVE
COMPARE
a type of igneous rock
CONTRAST
Slow cooling results in the formation of large crystals or coarse grained texture; forms deep in the earth, inside the volcano #6
Fast/rapid cooling of magma or lava results in rocks with small, interconnected mineral grains; forms outside the volcano #7
EXAMPLES
Granite
Rhyolite

43. Objective #2
Explain how the rate of cooling affects an igneous rock’s texture.
OBSIDIAN

45. Objective #3
Classify igneous rocks according to texture and composition.

46. 3.2 Igneous Rocks Classification of Igneous Rocks
 Igneous rocks can be classified based on their composition and texture. #9
When a large mass of magma solidify far below the Earth’s surface, they form igneous rocks that have a coarse grained texture.
1. Texture
A. Coarse Grained Texture
B. Fine Grained Texture
C. Glassy Texture
D. Porphorytic Texture

47. Coarse-Grained Igneous Texture
GRANITE
Coarse-grained texture is caused by slow cooling resulting in larger crystals, and small, interconnected mineral grains. #15

48. Fine-Grained Igneous Texture
RHYOLITE
Fine-grained texture is caused by rapid cooling resulting in smaller, interconnected mineral grains. #15

49. Obsidian Exhibits a Glassy Texture.
Lava that cools so quickly that ions do not have time to arrange themselves into crystals will form igneous rocks with a glassy texture or appearance.
Glassy texture is caused by very rapid cooling.

50. Porphyritic Igneous Texture
PORPHYRITIC ANDESITE
D. Porphyritic texture is caused by different rates of cooling resulting in two or multiple distinctly different sized minerals.

51. 3.2 Igneous Rocks Classification of Igneous Rocks 2. Composition
A. Granitic Composition
B. Basaltic Composition
C. Andesitic Composition
D. Ultramafic Composition

52. 3.2 Igneous Rocks
GRANITE
Made of
1. Quartz
2. Potassium Feldspar
3. Sodium-rich Plagioclase Feldspar
• Granitic composition – these intrusive igneous rocks crystallized from magma and are made mostly of light-colored quartz and feldspar. #10

53. Basalt
BASALT
Made of
1. Pyroxene
2. Calcium-rich Feldspar
• Basaltic composition –these rocks contain dark silicate minerals and plagioclase feldspar. #11

54. 3.2 Igneous Rocks ANDESITES
Made of
1. amphibole
2.pyroxene
3. biotite
4. plagioclase feldspar. #12
• Andesitic composition –these are extrusive igneous rocks are between granitic light-color minerals and basaltic composition dark-colored minerals.

55. 3.2 Igneous Rocks ULTRAMAFIC
Peridotite is an example of an ultramafic rock. #13
Much of the upper mantle is thought to be made of peridotite. #14
• Ultramafic composition – these intrusive igneous rocks are made mostly from iron and magnesium-rich minerals, and has extremely low silica content (below 45%).

56. Classification of Igneous Rocks

57. Classification of Igneous Rocks57

58. 3.2 QUIZZ
1. Compare and contrast the formation of intrusive and extrusive igneous rocks.
2. How do coarse-grained igneous rocks form?
3. How are igneous rocks classified according to composition?
4. How do fine-grained igneous rocks form?
5. How do igneous rocks with glassy textures form?

59. 3.2 ANSWER
1. Both types of rocks form when molten material cools and solidifies. Intrusive igneous rocks form when magma cools and solidifies within Earth. Extrusive igneous rocks form
when lava cools and hardens at the surface.
2. Coarse-grained igneous rocks form when magma cools slowly within Earth.

60. 3.2 ANSWER
3. Igneous rocks can be classified by composition based on the major minerals in the rocks. Light-colored rocks have granitic compositions. Dark-colored rocks have basaltic compositions. Dark-colored rocks that contain only olivine and pyroxene are ultramafic rocks.
4. Fine-grained igneous rocks form when lava cools quickly at Earth’s surface.
5. Igneous rocks with glassy textures form when lava cools very quickly.

61. 3.3 Sedimentary Rocks CALIFORNIA CONTENT STANDARD 3C
Students know how to explain the properties of rocks based on the physical and chemical conditions in which they formed, including plate tectonic processes.

62. 3.3 Sedimentary Rocks Section Objectives
Describe the major processes involved in the formation of sedimentary rocks.
Distinguish between clastic and chemical sedimentary rocks.
Identify the features that are unique to some sedimentary rocks.

63. 3.3 Sedimentary Rocks Vocabulary Erosion Deposition Compaction
Cementation
Clastic sedimentary rocks
Chemical sedimentary rocks

64. 3.3 Sedimentary Rocks
OBJECTIVE #2: What are clastic sedimentary rocks?
P. 77, 2nd paragraph

65. 3.3 Sedimentary Rocks II. Sedimentary Rocks A. Clastic Rocks
Reading Strategy
II. Sedimentary Rocks
A. Clastic Rocks
1. rock made up of weathered bits of rocks and
minerals
2. Common example of clastic sedimentary rock
is shale.
B. Chemical Rocks
1. rock that forms when dissolved minerals
precipitate from water
2. Common example of chemical sedimentary
rock is limestone.

66. 3.3 Sedimentary Rocks forms from forms from dissolved minerals#7
CLASTIC SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
forms from
dissolved minerals
that precipitate
from water
solutions
forms from
weathered bits
of rocks and
minerals
They’re both sedimentary rocks.

67. 3.3 Sedimentary Rocks Classification of Sedimentary Rocks
 Two Main Types
Clastic sedimentary rocks form by weathering processes which break down rocks into pebble, sand, or clay particles by exposure to wind, ice, and water. Clastic and nonclastic sedimentary rocks are the only members of the rock family that contain fossils.
1. Clastic sedimentary rocks are composed of weathered bits of rocks and minerals. RS IIA1, #7
• Classified by particle size
• Common rocks include #8
- Shale (most abundant) RS IIA2
- Sandstone
- Conglomerate
- Breccia

68. 3.3 Sedimentary Rocks Fossils are only found in sedimentary rocks.
Fossils are used for:
1. interpreting past environments
2. indicating when the rock formed
3. matching rocks of the same age found in different places

69. Shale with Plant Fossils

70. Conglomerate

71. Sandstone

72. Breccia

73. 3.3 Sedimentary Rocks
OBJECTIVE #3: What are chemical and biochemical sedimentary rocks?
p. 77, 3rd paragraph

74. 3.3 Sedimentary Rocks Classification of Sedimentary Rocks
 Two Main Types #7 mid venn diagram
2. Chemical sedimentary rocks form when dissolved substances precipitate, or separate, from water. RS IIB1, #7
Common rocks include
- limestone RS IIB2 - most abundant chemical rock
- microcrystalline quartz known as chert, flint, jasper, or agate
Layered gypsum composed of (CaSO4.2H20) of the Castille Formation, Carlsbad, New Mexico
- evaporites such as rock salt or gypsum
- coal

75. Fossiliferous Limestone

76. Microcrystalline Quartz (Chert)

77. Flint

78. Jasper

79. Agate

80. Gypsum

81. Chalk

82. The 4 Major Processes in the Formation of Sedimentary Rocks
 Weathering, Erosion, Deposition and Compaction & Cementation #11
~Weathering is the first step in the formation of sedimentary rocks. #6
~Weathered sediments don’t usually remain in place. #6
~ Small sediments are usually carried large distances before being deposited. #6
Sedimentary rocks form when solids settle out of a fluid such as water or air. #5

83. • Weathering is the breaking down of rocks in smaller pieces which may be caused by air, water or living things.Erosion involves the weathering and the removal of rock. #2

84. • Deposition occurs when an agent of erosion—water, wind, ice, or gravity—loses energy and drops sediments. #4

85. 3.3 Sedimentary Rocks Formation of Sedimentary Rocks
 Compaction and Cementation
In undisturbed sedimentary rocks, the oldest layers are found on the bottom. #9

86. • Compaction is a process that squeezes, or compacts, sediments. #1
Ripple marks in a sedimentary rock may indicate that the rock formed along a beach or stream bed. #10

87. • Cementation takes place when dissolved minerals are deposited in the tiny spaces among the sediments. #3

88. Classification of Sedimentary Rocks

89. 3.3 Sedimentary Rocks
OBJECTIVE #4: What features are unique to some sedimentary rocks?
P. 78, 2nd paragraph

90. 3.3 Sedimentary Rocks Features of Some Sedimentary Rocks
 Features of sedimentary rocks are clues to how and where the rocks are formed
Records the period of sediment deposition
Oldest layer is on the bottom, youngest layer is on the topmost layer
May show ripple marks and fossils
May show if the climate was hot or cold, rainy or dry during rock formation
May show how many years ago the rocks were formed

91. 3.3 Sedimentary Rocks

92. 3.3 QUIZZ 1. Contrast weathering, erosion, and deposition.
2. Name four clastic sedimentary rocks and explain how these rocks form.
3. Name four chemical sedimentary rocks and explain how these rocks form.
4. Explain how three different features of sedimentary rocks can be used to determine
how, where, or when the rocks formed.
5. What is compaction?

93. 3.3 ANSWERS
1. Weathering is any process in which rocks are broken down into smaller pieces. Erosion involves the weathering and removal of sediments. Deposition is the dropping of sediments by agents of erosion.
2. Conglomerate, breccia, sandstone, shale, and siltstone are clastic rocks. Clastic rocks form when bits of weathered materials are compacted and cemented together.

94. 3.3 ANSWERS
3. Most limestones, rock salt, rock gypsum, flint, and chert are chemical sedimentary rocks that form when dissolved minerals precipitate from water.
4. Each layer of a sedimentary rock records a period of deposition. Ripple marks indicate that a rock bed formed in water. Mud cracks are indicative of unusually dry periods. Fossils can be used to determine if a rock formed on land or in the ocean, if the climate was hot
or cold, or rainy or dry, and when the rock containing them formed.

95. 3.3 ANSWERS
5. Compaction is the process that squeezes, or compacts, sediments.

96. 3.4 Metamorphic Rocks California Content Standard 3c
Students know how to explain the properties of rocks based on the physical and chemical conditions in which they formed, including plate tectonic processes.
3.4 Metamorphic Rocks

97. CCSS.ELA-LITERACY.WHST.9-10.2.A
Introduce a topic and organize ideas, concepts, and information to make important connections and distinctions; include formatting (e.g., headings), graphics (e.g., figures, tables), and multimedia when useful to aiding comprehension.

98. 3.4 Metamorphic Rocks Objectives/Key Concepts
1. Predict where most metamorphism takes place.
2. Distinguish contact from regional metamorphism.
3. Identify the three agents of metamorphism and explain
what changes they cause.
4. Recognize foliated metamorphic rocks and describe how they form.
5. Classify metamorphic rocks.

99. 3.4 Metamorphic Rocks Vocabulary Words ◆ metamorphism ◆ contact
◆ regional
◆ hydrothermal
solution
◆ foliated
metamorphic rock
◆ nonfoliated

100. 3.4 Metamorphic Rocks Objective #1
Where does most metamorphism take place? p. 80, 2nd paragraph

101. 3.4 Metamorphic Rocks III. Metamorphic Rocks A. Foliated Rocks
Reading Strategy
3.4 Metamorphic Rocks
III. Metamorphic Rocks
A. Foliated Rocks
1. Rock that forms when minerals recrystallize
at right angle to the direction of pressure.
2. Common example of foliated metamorphic
rock is slate.
B. Nonfoliated Rocks
1. Rocks that doesn’t have a branded texture.
2. Common example of nonfoliated
metamorphic rock is marble.

102. 3.4 Metamorphic Rocks Formation of Metamorphic Rocks
 Metamorphism means “to change form.” #1
 Most metamorphic changes occur at elevated temperatures and pressures.
 Most metamorphic processes take place a few kilometers below the Earth’s surface and extend into the upper mantle.

103. Formation of Metamorphic Rocks
Most metamorphic changes occur at elevated temperatures and pressures. These conditions are found a few kilometers below Earth’s surface and extend into the upper mantle. Most metamorphism occurs in one of two settings - contact metamorphism or regional metamorphism. Changes that may occur during metamorphism include :
1. Certain minerals may recrystallize
2. Rocks become more compact
3. Crystals may grow larger

104. 3.4 Metamorphic Rocks Objective #2
How is contact metamorphism different from regional metamorphism?
p. 81, 1st and 2nd paragraph

105. 3.4 Metamorphic Rocks Formation of Metamorphic Rocks
 Regional metamorphism results in large-scale deformation #6 and high-grade metamorphism. #3
Directed pressures and high temperatures occur during mountain building. #8
Produces the greatest volume of metamorphic rock

106. 3.4 Metamorphic Rocks Formation of Metamorphic Rocks
 Contact Metamorphism occurs when magma moves into rocks. #2
Produces low grade metamorphism #4
Changes are driven by a rise in temperature. #5
The primary agent of contact metamorphism is heat.
Forms marble #7
Occurs near a body of magma

107. 3.4 Metamorphic Rocks Objective #3
What are three agents of metamorphism, and what kinds of changes does each cause?
p , 3rd and 4th paragraph

108. 3.4 Metamorphic Rocks Agents of Metamorphism #9  Heat  Pressure
Provides the energy needed to drive chemical reactions
 Pressure
Causes a more compact rock with greater density
During metamorphism,
rocks are usually subjected to more than one agent at a time. #10
 Hydrothermal Solutions

110. 3.4 Metamorphic Rocks Agents of Metamorphism  Heat
Causes minerals to recrystallize; causes new minerals to form #11
Promote recrystallization by dissolving original minerals and then depositing new ones

111. Origin of Pressure in Metamorphism
Pressure causes spaces between mineral grains to close; may cause minerals to recrystallize or to form new minerals; causes mineral grains to flatten and elongate. #11 A B
Figure 16 Pressure (Stress) As a Metamorphic Agent
A Forces in all directions are applied equally to buried rocks.
B During mountain building, rocks subjected to differential
stress are shortened in the direction that pressure is applied.

112. 3.4 Metamorphic Rocks Agents of Metamorphism  Hydrothermal Solutions
Hot water-based solutions escaping from the mass of magma
Solutions aid in recrystallization of minerals; promotes recrystallization
by dissolving original minerals and depositing new ones #11

113. 3.4 Metamorphic Rocks Objective #4
What are foliated metamorphic rocks, and how do they form?
p. 83, 4th paragraph

114. 3.4 Metamorphic Rocks Classification of Metamorphic Rocks
 Two main categories
1. Foliated Metamorphic Rock #12
Schist
(shist)
Crystals combine and form a banded or layered appearance
Pressure can form it
An example of this is Schist and Gneiss
Gneiss
(nice)

115. 3.4 Metamorphic Rocks Classification of Metamorphic Rocks
 Two main categories
2. Nonfoliated Metamorphic Rock #13
Does not have a banded texture
Examples include marble, quartzite and anthracite
marble
anthracite
quartzite

116. 3.4 Metamorphic Rocks Objective #5
How are metamorphic rocks classified?
p. 83, 4th and 5th paragraph

117. Classification of Metamorphic Rocks

118. Metamorphic Rock
118

119. 3.4 QUIZZ 1. Where does most metamorphism take place?
2. Compare and contrast contact metamorphism and regional metamorphism?
3. Name the agents of metamorphism and explain how each changes a rock.
4. What are foliated rocks, and how do they form?
5. How are metamorphic rocks classified?

120. 3.4 ANSWERS
1. Most metamorphism takes place in a zone that begins several kilometers below the surface and extends into the upper mantle.
2. Contact metamorphism is a process whereby slight changes occur in rocks as the result of an increase in temperature resulting from a magma body. Regional metamorphism, which is associated with mountain building, can result in high-grade changes in both composition and structure.

121. 3.4 ANSWERS
3. Heat can cause existing minerals to recrystallize or it can cause new minerals to form. Pressure produces a more compact rock with a greater density. Pressure also causes minerals to recrystallize. Fluids aid in recrystallization by making it easier for ions to move and by dissolving original minerals and depositing new ones.
4. Foliated rocks are banded metamorphic rocks that form when minerals realign as the result of pressure from opposing sides.

122. 3.4 ANSWERS
5. Metamorphic rocks can be classified according to composition and texture.

123. The end