The Earth Through Time

C H A P T E R 1 The Science of Historical Geology 1
Why Study Earth History? 2
Geology Lives in the Present and the Past 2
A Way to Solve Problems: The Scientific Method 3
E N R I C H M E N T Scientific Discoveries Must be Tested 5
Three Great Themes in Earth History 7
What Lies Ahead? 9
C H A P T E R 2 Early Geologists Tackle History s Mysteries 13
The Intrigue of Fossils 14
An Early Scientist Discovers Some Basic Rules 15
European Researchers Unravel the Succession of Strata 17
Neptunists and Plutonists Clash 18
Uniformitarianism: James Hutton Recognizes that the Present is Key to the Past 18
The Principle of Fossil Succession 20
The Great Uniformitarianism Catastrophism Controversy 21
The Principle of Cross–Cutting Relationships 21
Evolution: How Organisms Change Through Time 23
Earth History in America 24
C H A P T E R 3 Time and Geology 29
Finding the Age of Rocks: Relative Versus Actual Time 29
A Scale of Geologic Time 30
Actual Geologic Time: Clocks in the Rocks 34
Radioactivity Provides a Way to Date Rocks 36
What Occurs When Atoms Decay? 37
The Principal Radioactive Timekeepers 41
How Old is Earth? 45
C H A P T E R 4 Rocks and Minerals: Documents That Record Earth s History 49
Minerals as Documents of Earth History 50
Minerals and Their Properties 50
Common Minerals that Form Rocks 52
Earth s Three Great Rock Families and How They Formed 57
Igneous Rocks: Fire–Formed 58
Sedimentary Rocks: Layered Pages of History 67
Metamorphic Rocks: Changed without Melting 72
C H A P T E R 5 The Sedimentary Archives 81
Tectonic Setting is the Biggest Factor in Sediment Deposition 82
Environments Where Deposition Occurs 83
What Rock Color Tells Us 89
What Rock Texture Tells Us 91
E N R I C H M E N T You Are the Geologist 93
What Sedimentary Structures Tell Us 94
What Four Sandstone Types Reveal About Tectonic Setting 98
Limestones and How They Form 99
Organizing Strata to Solve Geologic Problems 103
Sea–Level Change Means Dramatic Environmental Change 106
Stratigraphy and the Correlating of Rock Bodies 107
Unconformities: Something is Missing 109
Depicting the Past 112
G E O L O G Y O F N A T I O N A L P A R K S A N D MO N UME N T S
Grand Canyon National Park, Arizona 118
C H A P T E R 6 Life on Earth: What Do Fossils Reveal? 125
Fossils: Surviving Records of Past Life 126
E N R I C H M E N T Amber, the Golden Preservative 129
E N R I C H M E N T The Mazon Creek Lagerst atte 131
Figuring Out How Life is Organized 132
Evolution: Continuous Changes in Life 133
The Case for Evolution 141
E N R I C H M E N T Earbones Through the Ages 142
Fossils and Stratigraphy 144
Fossils Indicate Past Environments 151
How Fossils Indicate Paleogeography 155
How Fossils Indicate Past Climates 158
An Overview of the History of Life 159
Life on Other Planets: Are We Alone? 163
C H A P T E R 7 Plate Tectonics Underlies All Earth History 169
Earthquake Waves Reveal Earth s Mysterious Interior 170
Earth s Internal Zones 172
Earth s Two Types of Crust 175
Plate Tectonics Ties It All Together 177
Drifting Continents 178
Evidence for Continental Drift 179
Paleomagnetism: Ancient Magnetism Locked Into Rocks 182
Today s Plate Tectonics 184
What Happens At Plate Margins? 189
What Drives Plate Tectonics? 194
Verifying Plate Tectonics Theory 195
E N R I C H M E N T Rates of Plate Movement 201
Thermal Plumes, Hotspots, and Hawaii 202
Exotic Terranes 202
Broken, Squeezed, or Stretched Rocks Produce Geologic Structures 205
G E O L O G Y O F N A T I O N A L P A R K S A N D M O N U M E N T S
Hawaii Volcanoes National Park 210
C H A P T E R 8 The Earth s Formative Stages and the Archean Eon 215
Earth in Context: A Little Astronomy 216
E N R I C H M E N T The Origin of the Universe 221
A Solar System Tour, From Center to Fringe 221
Following Accretion, Earth Differentiates 228
The Primitive Atmosphere Virtually No Oxygen 229
The Primitive Ocean and the Hydrologic Cycle 232
Origin of Precambrian Basement Rocks 232
The Origin of Life 238
G E O L O G Y O F N A T I O N A L P A R K S A N D M O N U M E N T S
Voyageurs National Park 246
In Retrospect 247
C H A P T E R 9 The Proterozoic: Dawn of a More Modern World 251
Highlights of the Paleoproterozoic (2.5 to 1.6 billion years ago) 253
E N R I C H M E N T The 18.2–Hour Proterozoic Day 255
Highlights of the Mesoproterozoic (1.6 to 1.0 billion years ago) 257
E N R I C H M E N T BIF: Civilization s Indispensable Treasure 258
Highlights of the Neoproterozoic (1.0 to 542 million years ago) 259
Proterozoic Rocks South of the Canadian Shield 260
E N R I C H M E N T Heliotropic Stromatolites 262
Proterozoic Life 263
C H A P T E R 1 0 Early Paleozoic Events 275
Dance of the Continents 277
Some Regions Tranquil, Others Active 277
Identifying the Base of the Cambrian 281
Early Paleozoic Events 281
Cratonic Sequences: The Seas Come in, the Seas Go Out 282
The Sauk and Tippecanoe Sequences 284
Way Out West: Events in the Cordillera 287
Deposition in the Far North 288
Dynamic Events in the East 289
G E O L O G Y O F N A T I O N A L P A R K S Jasper National Park 290
E N R I C H M E N T A Colossal Ordovician Ash Fall: Was it a Killer? 292
The Caledonian Orogenic Belt 296
E N R I C H M E N T The Big Freeze in North Africa 297
Aspects of Early Paleozoic Climate 298
C H A P T E R 1 1 Late Paleozoic Events 303
The Seas Come in, the Seas Go Out 306
Unrest Along the Western Margin of the Craton 309
E N R I C H M E N T The Wealth of Reefs 312
To the East, A Clash of Continents 315
Sedimentation and Orogeny in the West 323
Europe During the Late Paleozoic 326
Gondwana During the Late Paleozoic 327
Climates of the Late Paleozoic 327
Mineral Products of the Late Paleozoic 328
G E O L O G Y O F N A T I O N A L P A R K S A N D MO N U M E N T S
Acadia National Park 329
C H A P T E R 1 2 Life of the Paleozoic 335
Animals with Shells Proliferate and So Does Preservation 337
The Cambrian Explosion of Life: Amazing Fossil Sites in Canada and China 338
The Great Ordovician Biodiversification Event 343
A Variety of Living Strategies 343
Protistans: Creatures of a Single Cell 343
Marine Invertebrates Populate the Seas 344
E N R I C H M E N T The Eyes of Trilobites 360
Advent of the Vertebrates 363
The Rise of Fishes 364
Conodonts: Valuable But Enigmatic Fossils 370
Advent of Tetrapods 370
Plants of the Paleozoic 374
E N R I C H M E N T A Walk Through an Ancient Rainforest 377
Mass Extinctions 377
C H A P T E R 1 3 Mesozoic Events 385
The Breakup of Pangea 386
The Mesozoic in Eastern North America 387
The Mesozoic in Western North America 390
G E O L O G Y O F N A T I O N A L P A R K S A N D MO N U M E N T S
Zion National Park 394
E N R I C H M E N T Did Seafloor Spreading Cause Cretaceous Epicontinental Seas? 401
The Tethys Sea in Europe 406
G E O L O G Y O F N A T I O N A L P A R K S A N D MO N U M E N T S
Grand Staircase Escalante National Monument 407
Gondwana Events 410
E N R I C H M E N T Chunneling Through the Cretaceous 411
C H A P T E R 1 4 Life of the Mesozoic 417
Climate Controls It All 418
Mesozoic Invertebrates 421
Mesozoic Vertebrates 426
Dinosaurs: Terrifying Lizards 429
G E O L O G Y O F N A T I O N A L P A R K S A N D MO N U M E N T S
Dinosaur National Monument 430
Dinosaurs: Cold–blooded, Warm–blooded, or Both? 444
Dinosaur Parenting 445
E N R I C H M E N T Can We Bring Back the Dinosaurs? 445
Flying Reptiles 446
Dragons of the Seas 448
The Rise of Modern Birds 449
E N R I C H M E N T The Archaeopteryx Controversy 450
The Mammalian Vanguard 451
Sea Plants and Phytoplankton 455
Land Plants 457
Late Cretaceous Catastrophe 459
E N R I C H M E N T Bolides and Modern Day Catastrophism 463
C H A P T E R 1 5 Cenozoic Events 469
The Tectonics Climate Connection 470
Stability and Erosion Along the North American Eastern Margin 472
Gulf Coast: Transgressing and Regressing Sea 473
The Mighty Cordillera 473
E N R I C H M E N T Oil Shale 477
Creating the Basin and Range Province 478
G E O L O G Y O F N A T I O N A L P A R K S A N D MO N UME N T S
Badlands National Park, South Dakota 479
E N R I C H M E N T Hellish Conditions in the Basin and Range Province 482
Colorado Plateau Uplift 482
Columbia Plateau and Cascades Volcanism 482
Sierra Nevada and California 485
The New West Coast Tectonics 487
Meanwhile, Drama Overseas 488
Big Freeze: The Pleistocene Ice Age 491
What Caused the Ice Age? 497
Cenozoic Climates: Global Warming Then Cooling 501
C H A P T E R 1 6 Life of the Cenozoic 505
Grasslands Expand, Mammals Respond 507
Plankton 508
Marine Invertebrates 509
Vertebrates 512
Mammals 517
Monotremes 519
Marsupials 519
Placental Mammals 520
E N R I C H M E N T How the Elephant Got Its Trunk 536
Demise of the Pleistocene Giants 539
C H A P T E R 1 7 Human Origins 543
Primates 544
Modern Primates 546
Primate Beginnings 547
The Early Anthropoids 550
The Australopithecine Stage and the Emergence of Hominins 552
A Species in Transition: Australopithecus Sediba 554
The Homo Erectus Stage 556
Final Stages of Human Evolution 557
E N R I C H M E N T Being Upright: Good News, Bad News 558
E N R I C H M E N T Neandertal or Neanderthal? 559
E N R I C H M E N T Neandertal Ritual 560
Humans Arrive in the Americas 563
Human Population: 7 Billion and Growing 565
What Lies Ahead? 566
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