Geology 101 Study Guide Test #2

Chapter 5
Know how sedimentary rocks are classified based on texture (clastic rocks, Figure 5.4) and chemical composition (chemical/organic rocks). Be able to identify a sedimentary rock if given a description (i.e., if I give you grain size, you should be able to tell me the type of clastic rock).

Understand how grain size relates to the energy of the depositional system. Understand transgression and regression. Given a stratigraphic sequence of sedimentary rocks, be able to determine whether that sequence is a record of transgression or regression.

Be able to define/identify these sedimentary structures: stratification, cross bedding, graded bedding, ripple marks, mud cracks. Know how these structures relate to the depositional environment (e.g., how/where they form). FIGURE 5.2, FIGURE 5.9 Cross-bedding, Figure 5.10 Graded bedding

The type of rock and its structures are important records of past depositional environments. Know the major sedimentary systems, their important characteristics and types of sediments that accumulate in them (Figures 5.13; and 5.14-5.25; are key).

In other words, know how sedimentary rocks form and how their formation and structural features relate to depositional environments.

Chapter 6
Know the rock cycle this links all the various rock types to plate tectonics and surface processes.

Know how metamorphic rocks form, including the processes of recrystalization, plastic deformation. Know how metamorphism occurs under pressure, temperature, and composition changes; understand where these conditions take place in relation to plate tectonics (figures 6.4 (Where), 6.6, 6.19 are a good place to start). The driving forces for metamorphism are changes in temperature, pressure, and composition of the environment or strong deformation.These changes cause recrystallization in the solid state as the rock changes toward equilibrium with the new environment.

Understand stability diagrams and be able to use them to predict what mineral would be stable under given environmental conditions. Figure 6.5

Know how metamorphic rocks are classified; be able to identify the common metamorphic rocks presented in class and lab (and in the chapter). Understand why some rocks are foliated and some are not. Know figure 13. Foliation is caused by differential stress and shearing. Usually occurs during the recrystallization step.

Understand figure 6.16. Be able to use information about metamorphic facies to identify metamorphic grade in relation to plate tectonics (again, figure 6.19 will help with this). Where and why

In other words, know how and under what conditions rocks are metamorphosed, what a given rock metamorphoses into for a given set of conditions (high temperature metamorphism of sandstone equals quartzite), where those conditions and their associated metamorphic rocks occur.

Chapter 7
Now that weve created rocks in chapters 3-6, chapter 7 discusses how we modify their structure.

Be able to identify the types of folds, geometries of folds, and types of faults that can occur. Be able to link the types of stress and types of deformation that give rise to these structures. Know what factors influence how a given rock body deforms in response to a given stress. Figure 7.4

Know the terminology associated with folds and faults (limb, hinge, hanging wall, etc.). Be able to identify folds and faults given a description of the dip of limbs, ages of rocks as you walk from the limb to the hinge axis, direction of movement of the hanging wall, etc. We did a large number of examples of this in class. Hanging wall, footwall, forelimb, back limb, top limb. Figure 7.11. Rule of vs (Figure 7.15) Eroded Vs point the direction the bed dips

Be able to identify a plunging fold, whether it is an anticline or syncline, and its major features (direction the v points, dip of the limbs, etc). Age of rock (syncline and anticline)

Know the large scale features that result from regional stress fold and thrust belts, horst and graben, shortening and thickening of the crust, etc.

Be able to identify the type of plate margin given a description (or figure) of the dominant structural features. And be able to do the reverse (give the most likely structural features that would occur at a given plate boundary). In other words, be able to use the information above to relate structural features to plate tectonics.

In other words, know how rocks are deformed, the processes that influence that deformation, the types of structures that result, and where those structures occur with respect to tectonic setting.

Chapter 8
Know the difference and importance of both relative and absolute dating.

Know the relative dating tools (principles) and unconformities. Be able to identify examples of each. Be able to use these to place a sequence of events in relative order (given a description or a cross section). (Major Concepts #2)

Understand the principle of absolute dating. Know how elements radioactively decay, how this relates to half-life (and whether radioactive decay occurs linearly or exponentially), and how geologists use unstable (radioactive) isotopes to date a sample. Be able to determine the number of half-lives required to remove a given fraction of radioactive atoms (or the reverse: what fraction of radioactive atoms remain after a given number of half-lives). Figure 8.11

Know how absolute ages of crust relate to the major features of the continents.

Know what evidence geologists use to determine the age of the earth. Potassium-Argon Dating

Understand how the standard geologic column was first developed (the relative dating tools), and how absolute dating has improved our understanding of the time divisions within that column. FIGURE 8.8 (caption) The original order of the units in the geologic column was based on the sequence of rock formations in their superposed order as they are found in Europe.

In other words, know the difference between relative and absolute dating, how we date rock sequences using both methods, and why both methods are important.

Chapter 18
Understand elastic rebound and how it relates to earthquakes. Figure 1.8

Know the difference between P, S, and surface waves (in terms of motion, speed, etc.) Figure 18.3. Know the differences between the schemes used to determine the intensity(measured in relation to effects on humans)/magnitude(objective scale of energy released) of an earthquake moment magnitude is the most widely used today. Know how we use the properties and energy of the waves to locate the epicenter and focus of an earthquake (figure 18.4)

Understand how the distribution of focal depths around the world relates to plate boundaries.

Know how material properties affect how/whether the different seismic waves are transmitted through the earth. Be able to describe how this is evidence that the earth is a differentiated planet (figures 18.15-18.22 will help a lot). Also, be able to relate material properties at the surface to the level of property damage that occurs due to an earthquake of a given magnitude.

Chapter 17
Understand the theories of continental drift and plate tectonics, the difference between the two, and the evidences for each.

Understand paleomagnetism, how it is recorded in the rock record (both on continents and in the seafloor), and why it is important.

Know the major plates and types of plate boundaries. Know how we determine plate boundaries. Know the processes that occur at convergent and divergent plate boundaries (e.g., seismicity, magmatism, metamorphism, structural features, etc).

Know how magmatism occurs at divergent and convergent plate margins.

In other words, understand how plate tectonics explains the dynamic evolution of the earth evident at the surface.

Chapter 23
Understand the relationship between tectonism, the hydrologic cycle, differential erosion, and climate in the production of landforms.

Know the relationship between elevation, erosion, and isostasy. Figure 23.4, 5

Know the primary geomorphic landscapes that occur on all continents (there are three of them Shield, stable platform, folded mountain belt). Also know these geomorphic landscapes that occur on some continents: rift systems and magmatic arcs. Know how these geomorphic provinces form and the distinctive landforms that develop for each pay special attention to the examples from the US.

The production of landforms play a key role in determining the rock types exposed at the surface. Know how the basic rock types exposed at the surface of the continent relate to geomorphic landscapes.

In other words, understand the processes that influence the evolution of landforms and how these landforms relate to tectonic setting.

Earth Science

NR 410102 Engineering Geology



Object of class

Metamorphic Rocks

Transform Plate Boundaries

Transform plate boundaries are zones of shearing where plates slide horizontally past each other. In the process, lithosphere is neither created nor consumed but significant topographic features are produced.


1. There are three major types of transform boundaries: (a) ridge-ridge, (b) ridge-trench, and (c) trench-trench.

2. The shearing process involved with transform boundaries produces parallel ridges and troughs, pull-apart basins, and folds.

3. Transform faults are related to large fracture zones that may extend thousands of kilometers across the ocean floor.

4. Oceanic fracture zones may be several kilometers wide. The structure and topography of fracture zones are generally related to spreading rate.

5. Continental transform faults are similar to oceanic transforms, but they lack the fracture zone extensions.

6. Shallow earthquakes are common along transform boundaries but not along the inactive fracture zones.

7. Volcanism is rare along transforms, but locally, basaltic extrusions result from leaky transforms.

8. Metamorphism along transform boundaries produces rocks with a strongly sheared fabric as well as hydrated oceanic basalts.


Students will become familiar with the characteristics of transform faults and associated fracture zones and will learn how they are produced by the global tectonic system. After studying this chapter, they will be able to:

1. Recognize the global pattern of transform boundaries and identify the major types.

2. Explain the difference between transform faults and fracture zones.

3. Describe the characteristics of the Romanche and Clipperton fracture zones.

4. Explain how compression and tensional structures are produced along fracture zones.

5. Explain how the midocean ridge produces a distinctive thermal structure where it butts against a transform fault.

6. Describe the characteristics of the San Andreas, Dead Sea, and Alpine transform systems.


What are the most significant characteristics of transform plate boundaries?

1. What type of movement occurs along a transform fault?

2. How are transforms related to the oceanic ridge?

3. What are the major topographic features produced along transform boundaries?

4. How are transform faults related to fracture zones?

5. What are the major types of transform faults? Why are they called transform?

What are the characteristics of oceanic transform faults and associated fracture zones?

1. What are their lengths? Their widths?

2. Why might a cliff on the side of a fracture zone be on one side and then the other?

3. What is the thermal structure of a transform?

4. Why does slow shearing produce different features than those produced by fast shearing transforms?

What are the characteristics of continental transform boundaries?

1. What are the typical topographic features produces along continental transforms?

2. Compare the San Andreas, Dead Sea, and Alpine transform boundaries. How are they similar? How do they differ?

3. What type of seismic activity occurs along transform boundaries?

Geology FINAL
Physical Geology content

Introducing Geology and an Overview of Important Concepts 3
Who Needs Geology? 4
Supplying Things We Need 4
Protecting the Environment 5
Avoiding Geologic Hazards 5
Understanding Our Surroundings 8
Earth Systems 9
An Overview of Physical Geology-Important Concepts 10
Internal Processes: How the Earth''s Internal Heat Engine Works 12
Earth''s Interior 12
The Theory of Plate Tectonics 13
Surficial Processes: The Earth''s External Heat Engine 16
Geologic Time 17
Atoms, Elements, and Minerals 25
Introduction 26
Atoms and Elements 27
Chemical Activity 30
Ions 30
Chemical Composition of the Earth''s Crust 30
Crystallinity 32
The Silicon-Oxygen Tetrahedron 33
Nonsilicate Minerals 35
Minerals 35
Crystalline Solid 37
Geologic Processes 37
Specific Chemical Composition 37
The Important Minerals 37
The Physical Properties of Minerals 40
Color 40
Streak 40
Luster 40
Hardness 40
External Crystal Form 41
Cleavage 43
Fracture 44
Specific Gravity 45
Special Properties 46
Other Properties 46
Chemical Tests 47
Igneous Rocks, Intrusive Activity, and the Origin of Igneous Rocks 51
The Rock Cycle 52
A Plate-Tectonic Example 53
Igneous Rocks 53
Igneous Rock Textures 55
Identification of Igneous Rocks 57
Varieties of Granite 58
Chemistry of Igneous Rocks 58
Intrusive Bodies 60
Shallow Intrusive Structures 60
Intrusives That Crystallize at Depth 61
Abundance and Distribution of Plutonic Rocks 63
How Magma Forms 64
Heat for Melting Rock 64
Factors That Control Melting Temperatures 64
How Magmas of Different Compositions Evolve 66
Sequence of Crystallization and Melting 66
Differentiation 67
Partial Melting 68
Assimilation 68
Mixing of Magmas 69
Explaining Igneous Activity by Plate Tectonics 69
Igneous Processes at Divergent Boundaries 69
Intraplate Igneous Activity 69
Igneous Processes at Convergent Boundaries 70
Volcanism and Extrusive Rocks 77
Introduction 78
Living with Volcanoes 81
Supernatural Beliefs 81
The Growth of an Island 81
Geothermal Energy 81
Effect on Climate 81
Volcanic Catastrophes 81
Eruptive Violence and Physical Characteristics of Lava 84
Extrusive Rocks and Gases 85
Scientific Investigation of Volcanism 85
Gases 85
Extrusive Rocks 86
Composition 86
Extrusive Textures 87
Types of Volcanoes 89
Shield Volcanoes 90
Cinder Cones 92
Composite Volcanoes 94
Volcanic Domes 96
Lava Floods 99
Submarine Eruptions 100
Pillow Basalts 100
Weathering and Soil 107
Weathering, Erosion, and Transportation 108
Weathering and Earth Systems 108
Solar System 108
Atmosphere 109
Hydrosphere 109
Biosphere 109
How Weathering Alters Rock 109
Effects of Weathering 109
Mechanical Weathering 111
Frost Action 111
Pressure Release 111
Other Processes 111
Chemical Weathering 113
Role of Oxygen 114
Role of Acids 114
Solution Weathering 114
Chemical Weathering of Feldspar 116
Chemical Weathering of Other Minerals 116
Weathering Products 118
Weathering and Climate 118
Soil 118
Soil Horizons 119
Soil Classification 119
Residual and Transported Soils 120
Soils, Parent Material, Time, and Slope 120
Organic Activity 122
Soils and Climate 122
Buried Soils 124
Sediment and Sedimentary Rocks 127
Sediment 129
Transportation 129
Deposition 130
Preservation 131
Lithification 132
Types of Sedimentary Rocks 133
Clastic Rocks 133
Breccia and Conglomerate 133
Sandstone 135
The Fine-Grained Rocks 136
Chemical Sedimentary Rocks 137
Carbonate Rocks 137
Chert 141
Evaporites 141
Organic Sedimentary Rocks 142
Coal 142
The Origin of Oil and Gas 142
Sedimentary Structures 142
Formations 147
Interpretation of Sedimentary Rocks 148
Source Area 148
Environment of Deposition 150
Plate Tectonics and Sedimentary Rocks 152
Metamorphism, Metamorphic Rocks, and Hydrothermal Rocks 157
Introduction 158
Factors Controlling the Characteristics of Metamorphic Rocks 159
Composition of the Parent Rock 160
Temperature 160
Pressure 160
Fluids 162
Time 162
Classification of Metamorphic Rocks 163
Types of Metamorphism 163
Contact Metamorphism 163
Regional Metamorphism 165
Plate Tectonics and Metamorphism 169
Hydrothermal Processes 172
Hydrothermal Activity at Divergent Plate Boundaries 172
Water at Convergent Boundaries 173
Metasomatism 173
Hydrothermal Rocks and Minerals 174
Time and Geology 179
The Key to the Past 180
Relative Time 181
Principles Used to Determine Relative Age 181
Unconformities 186
Correlation 187
The Standard Geologic Time Scale 191
Numerical Age 193
Isotopic Dating 193
Uses of Isotopic Dating 196
Combining Relative and Numerical Ages 198
Age of the Earth 199
Comprehending Geologic Time 201
Mass Wasting 205
Classification of Mass Wasting 206
Rate of Movement 206
Type of Material 206
Type of Movement 206
Controlling Factors in Mass Wasting 208
Gravity 210
Water 210
Triggering Mechanisms 211
Common Types of Mass Wasting 212
Creep 212
Debris Flow 213
Rockfalls and Rockslides 217
Underwater Slides 220
Preventing Landslides 221
Preventing Mass Wasting of Debris 221
Preventing Rockfalls and Rockslides on Highways 222
Streams and Floods 227
Earth Systems-The Hydrologic Cycle 229
Channel Flow and Sheet Flow 229
Drainage Basins 230
Drainage Patterns 231
Factors Affecting Stream Erosion and Deposition 231
Velocity 232
Gradient 233
Channel Shape and Roughness 233
Discharge 234
Stream Erosion 235
Stream Transportation of Sediment 236
Stream Deposition 237
Bars 237
Braided Streams 240
Meandering Streams and Point Bars 241
Flood Plains 243
Deltas 243
Alluvial Fans 246
Kaibab Limestone
Toroweap Formation
Coconino Sandstone
Hermit Shale
Supai Formation
Redwall Limestone
Hermit Shale
Supai Formation
Redwall Limestone
Flooding 246
Urban Flooding 247
Flash Floods 247
Controlling Floods 251
The Great Flood of 1993 251
Stream Valley Development 253
Downcutting and Base Level 253
The Concept of a Graded Stream 253
Lateral Erosion 255
Headward Erosion 255
Stream Terraces 256
Incised Meanders 257
Superposed Streams 257
Ground Water 263
Introduction 264
Porosity and Permeability 264
The Water Table 265
The Movement of Ground Water 267
Aquifers 268
Wells 269
Springs and Streams 270
Contamination of Ground Water 272
Balancing Withdrawal and Recharge 277
Effects of Ground-Water Action 277
Caves, Sinkholes, and Karst Topography 277
Other Effects 280
Hot Water Underground 281
Geothermal Energy 282
Glaciers and Glaciation 287
The Theory of Glacial Ages 288
Glaciers-What They Are, How They Form and Move 289
Distribution of Glaciers 289
Types of Glaciers 289
Formation and Growth of Glaciers 291
Movement of Valley Glaciers 292
Movement of Ice Sheets 296
Glacial Erosion 298
Erosional Landscapes Associated with Alpine Glaciation 298
Erosional Landscapes Associated with Continental Glaciation 301
Glacial Deposition 302
Moraines 303
Outwash 305
Glacial Lakes and Varves 306
Effects of Past Glaciation 308
The Glacial Ages 308
Direct Effects of Past Glaciation in North America 309
Indirect Effects of Past Glaciation 310
Evidence for Older Glaciation 311
Deserts and Wind Action 317
Distribution of Deserts 318
Some Characteristics of Deserts 319
Desert Features in the Southwestern United States 322
Wind Action 326
Wind Erosion and Transportation 326
Wind Deposition 328
Waves, Beaches, and Coasts 339
Introduction 340
Water Waves 340
Surf 341
Near-shore Circulation 342
Wave Refraction 342
Longshore Currents 342
Rip Currents 342
Beaches 344
Longshore Drift of Sediment 345
Human Interference with Sand Drift 346
Sources of Sand on Beaches 348
Coasts and Coastal Features 348
Erosional Coasts 349
Depositional Coasts 350
Drowned Coasts 351
Uplifted Coasts 352
The Biosphere and Coasts 353
Geologic Structures 359
Introduction 360
Tectonic Forces at Work 360
Stress and Strain in the Earth''s Crust 360
Behavior of Rocks to Stress and Strain 361
Present Deformation of the Crust 362
Structures as a Record of the Geologic Past 362
Geologic Maps and Field Methods 362
Folds 365
Geometry of Folds 365
Interpreting Folds 368
Fractures in Rock 369
Joints 369
Faults 370
Earthquakes 383
Introduction 384
Causes of Earthquakes 386
Seismic Waves 387
Body Waves 388
Surface Waves 389
Locating and Measuring Earthquakes 389
Determining the Location of an Earthquake 389
Measuring the Size of an Earthquake 392
Location and Size of Earthquakes in the United States 395
Effects of Earthquakes 395
Tsunami 399
World Distribution of Earthquakes 403
First-Motion Studies of Earthquakes 403
Earthquakes and Plate Tectonics 405
Earthquakes at Plate Boundaries 405
Subduction Angle 407
Earthquake Prediction and Seismic Risk 407
Earth''s Interior and Geophysical Properties 417
Introduction 418
Evidence from Seismic Waves 418
Earth''s Internal Structure 421
The Crust 421
The Mantle 422
The Core 424
Isostasy 428
Gravity Measurements 429
Earth''s Magnetic Field 432
Magnetic Reversals 433
Magnetic Anomalies 434
Heat Within the Earth 437
Geothermal Gradient 437
Heat Flow 438
The Sea Floor 443
Origin of the Ocean 444
Methods of Studying the Ocean Floor 444
Features of the Sea Floor 446
Continental Shelves and Continental Slopes 446
Submarine Canyons 448
Turbidity Currents 449
Passive Continental Margins 450
The Continental Rise 451
Abyssal Plains 451
Active Continental Margins 452
Oceanic Trenches 452
The Mid-Oceanic Ridge 453
Geologic Activity on the Ridge 453
Biologic Activity on the Ridge 455
Fracture Zones 455
Seamounts, Guyots, and Aseismic Ridges 456
Reefs 457
Sediments of the Sea Floor 459
Oceanic Crust and Ophiolites 459
The Age of the Sea Floor 462
The Sea Floor and Plate Tectonics 462
Plate Tectonics 467
The Early Case for Continental Drift 469
Skepticism About Continental Drift 472
Paleomagnetism and the Revival of Continental Drift 472
Recent Evidence for Continental Drift 473
History of Continental Positions 474
Seafloor Spreading 474
Hess''s Driving Force 474
Explanations 475
Plates and Plate Motion 476
How Do We Know That Plates Move? 477
Marine Magnetic Anomalies 477
Another Test: Fracture Zones and Transform Faults 480
Measuring Plate Motion Directly 480
Divergent Plate Boundaries 481
Transform Boundaries 484
Convergent Plate Boundaries 485
Ocean-Ocean Convergence 486
Ocean-Continent Convergence 487
Continent-Continent Convergence 489
Backarc Spreading 490
The Motion of Plate Boundaries 490
Plate Size 491
The Attractiveness of Plate Tectonics 491
What Causes Plate Motions? 492
Mantle Plumes and Hot Spots 494
The Relationship Between Plate Tectonics and Ore Deposits 497
A Final Note 498
Mountain Belts and the Continental Crust 503
Characteristics of Major Mountain Belts 506
Size and Alignment 506
Ages of Mountain Belts and Continents 506
Thickness and Characteristics of Rock Layers 508
Patterns of Folding and Faulting 508
Metamorphism and Plutonism 510
Normal Faulting 510
Thickness and Density of Rocks 510
Features of Active Mountain Ranges 511
The Evolution of a Mountain Belt 511
The Accumulation Stage 511
The Orogenic Stage 512
The Uplift and Block-Faulting Stage 515
The Growth of Continents 520
Displaced Terranes 520
Geologic Resources 525
Types of Resources 526
Resources and Reserves 527
Energy Use 527
Oil and Natural Gas 528
The Occurrence of Oil and Gas 528
Recovering the Oil 529
How Much Petroleum Do We Have Left? 530
Heavy Crude and Oil Sands 530
Oil Shale 532
Coal 532
Varieties of Coal 532
Occurrence of Coal 533
Environmental Effects 535
Reserves and Resources 535
Uranium 535
Alternative Sources of Energy 536
Metals and Ores 536
Origin of Metallic Ore Deposits 536
Ores Associated with Igneous Rocks 537
Ores Formed by Surface Processes 538
Mining 539
Environmental Effects 539
Some Important Minerals 540
Iron 540
Copper 541
Aluminum 541
Lead 541
Zinc 542
Silver 542
Gold 542
Other Metals 543
Nonmetallic Resources 543
Construction Materials 543
Fertilizers and Evaporites 544
Other Nonmetallics 544
Some Future Trends 544
The Human Perspective 544
The Earth''s Companions 549
The Earth in Space 550
The Sun 550
The Solar System 550
The Milky Way and the Universe 554
Origin of the Planets 554
The Solar Nebula 554
Formation of the Planets 556
Formation of Moons 557
Final Stages of Planet Formation 557
Formation of Atmospheres 557
Other Planetary Systems 557
Portraits of the Planets 558
Our Moon 558
Description of the Moon 559
Structure of the Moon 562
Origin and History of the Moon 562
Mercury 564
Venus 565
Mars 566
Why Are the Terrestrial Planets So Different? 570
Jupiter 571
Saturn 573
Uranus 574
Neptune 574
Pluto 575
Minor Objects of the Solar System 575
Meteors and Meteorites 575
Asteroids 576
Comets 576
Giant Impacts 578
Giant Meteor Impacts 578
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