viii
PREFACE
xvii
1 An Introduction
to Geology 1
The Science of Geology 2
Geology, People, and the Environment 3
Historical Notes about Geology 4
Catastrophism 4
The Birth of Modern Geology 5
Geology Today 5
Geologic Time 6
The Magnitude of Geologic Time 6
Relative Dating and the Geologic Time Scale 7
The Nature of Scientific Inquiry 8
Hypothesis 8
Theory 9
Scientific Methods 9
Do Glaciers Move? An Application of the
Scientific Method 10
Earth’s Spheres 11
Hydrosphere 12
Atmosphere 13
Biosphere 14
Geosphere 14
Earth as a System 15
Earth System Science 15
The Earth System 16
• The Rock Cycle: One of Earth’s
Subsystems 18
The Basic Cycle 20
Alternative Paths 20
Early Evolution of Earth 20
Origin of Planet Earth 20
Formation of Earth’ s Layered Structure 22
• Earth’s Internal Structure 23
Earth’ s Crust 23
Earth’ s Mantle 24
Earth’ s Core 24
The Face of Earth 24
Major Features of the Continents 25
Major Features of the Ocean Basins 25
• Dynamic Earth 28
A Brief Introduction to the Theory of Plate
Tectonics 28
Plate Boundaries 29
THE CHAPTER IN REVIEW 33
KEY TERMS 34 GIVE IT SOME THOUGHT 35
COMPANION WEBSITE 35
2 Matter and Minerals 36
• Minerals: Building Blocks of Rocks 38
Atoms: Building Blocks of Minerals 40
Properties of Protons, Neutrons, and Electrons 40
Elements: Defined by Their Number of Protons 40
Why Atoms Bond 41
Octet Rule 41
Ionic Bonds: Electrons Transferred 42
Covalent Bonds: Electrons Shared 43
Metallic Bonds: Electrons Free to Move 43
Isotopes and Radioactive Decay 44
• Physical Properties of Minerals 44
Optical Properties 44
Crystal Shape or Habit 45
Mineral Strength 46
Density and Specific Gravity 48
Other Properties of Minerals 48
• Mineral Groups 49
The Silicates 49
Silicate Structures 49
Joining Silicate Structures 50
• Common Silicate Minerals 51
The Light Silicates 53
The Dark Silicates 54
• Important Nonsilicate Minerals 55
Mineral Resources 56
THE CHAPTER IN REVIEW 60 KEY TERMS 60
GIVE IT SOME THOUGHT 60
COMPANION WEBSITE 60
3 Igneous Rocks
and Intrusive Activity 62
• Magma: The Parent Material of Igneous
Rock 64
The Nature of Magma 64
From Magma to Crystalline Rock 65
Igneous Processes 65
• Igneous Compositions 65
Granitic (Felsic) Versus Basaltic (Mafic) Compositions 66
Other Compositional Groups 67
Silica Content as an Indicator of Composition 67
C O N T E N T S
GEODe
ESSENTIALS
OF GEOLOGY
• Indicates sections with a corresponding
GEODe activity on mygeoscienceplace.com.
PREFACE
xvii
1 An Introduction
to Geology 1
The Science of Geology 2
Geology, People, and the Environment 3
Historical Notes about Geology 4
Catastrophism 4
The Birth of Modern Geology 5
Geology Today 5
Geologic Time 6
The Magnitude of Geologic Time 6
Relative Dating and the Geologic Time Scale 7
The Nature of Scientific Inquiry 8
Hypothesis 8
Theory 9
Scientific Methods 9
Do Glaciers Move? An Application of the
Scientific Method 10
Earth’s Spheres 11
Hydrosphere 12
Atmosphere 13
Biosphere 14
Geosphere 14
Earth as a System 15
Earth System Science 15
The Earth System 16
• The Rock Cycle: One of Earth’s
Subsystems 18
The Basic Cycle 20
Alternative Paths 20
Early Evolution of Earth 20
Origin of Planet Earth 20
Formation of Earth’ s Layered Structure 22
• Earth’s Internal Structure 23
Earth’ s Crust 23
Earth’ s Mantle 24
Earth’ s Core 24
The Face of Earth 24
Major Features of the Continents 25
Major Features of the Ocean Basins 25
• Dynamic Earth 28
A Brief Introduction to the Theory of Plate
Tectonics 28
Plate Boundaries 29
THE CHAPTER IN REVIEW 33
KEY TERMS 34 GIVE IT SOME THOUGHT 35
COMPANION WEBSITE 35
2 Matter and Minerals 36
• Minerals: Building Blocks of Rocks 38
Atoms: Building Blocks of Minerals 40
Properties of Protons, Neutrons, and Electrons 40
Elements: Defined by Their Number of Protons 40
Why Atoms Bond 41
Octet Rule 41
Ionic Bonds: Electrons Transferred 42
Covalent Bonds: Electrons Shared 43
Metallic Bonds: Electrons Free to Move 43
Isotopes and Radioactive Decay 44
• Physical Properties of Minerals 44
Optical Properties 44
Crystal Shape or Habit 45
Mineral Strength 46
Density and Specific Gravity 48
Other Properties of Minerals 48
• Mineral Groups 49
The Silicates 49
Silicate Structures 49
Joining Silicate Structures 50
• Common Silicate Minerals 51
The Light Silicates 53
The Dark Silicates 54
• Important Nonsilicate Minerals 55
Mineral Resources 56
THE CHAPTER IN REVIEW 60 KEY TERMS 60
GIVE IT SOME THOUGHT 60
COMPANION WEBSITE 60
3 Igneous Rocks
and Intrusive Activity 62
• Magma: The Parent Material of Igneous
Rock 64
The Nature of Magma 64
From Magma to Crystalline Rock 65
Igneous Processes 65
• Igneous Compositions 65
Granitic (Felsic) Versus Basaltic (Mafic) Compositions 66
Other Compositional Groups 67
Silica Content as an Indicator of Composition 67
C O N T E N T S
GEODe
ESSENTIALS
OF GEOLOGY
• Indicates sections with a corresponding
GEODe activity on mygeoscienceplace.com.