Understanding Earth

Meet the Authors     viPreface     xiiiThe Modern Theory and Practice of GeologyThe Earth System     1The Scientific Method     2Earth's Shape and Surface     3The Geologic Record     4Peeling the Onion: Discovery of a Layered Earth     6Earth as a System of Interacting Components     10An Overview of Geologic Time     14Plate Tectonics: The Unifying Theory     18The Discovery of Plate Tectonics     19The Mosaic of Plates     22Rates and History of Plate Motions     30The Grand Reconstruction     35Mantle Convection: The Engine of Plate Tectonics     37The Theory of Plate Tectonics and the Scientific Method     42Basic Geologic ProcessesEarth Materials: Minerals and Rocks     44What Are Minerals?     45The Atomic Structure of Matter     46Chemical Reactions     47Chemical Bonds     49The Atomic Structure of Minerals     49Rock-Forming Minerals     52Physical Properties of Minerals     56What Are Rocks?     62Igneous Rocks     63SedimentaryRocks     64Metamorphic Rocks     66The Rock Cycle: Interactions Between the Plate Tectonic and Climate Systems     66Minerals Occur in Rocks as Valuable Resources     68Earth Issues: Sulfide Minerals React to Form Acid Waters on Earth and Mars     57Igneous Rocks: Solids from Melts     76How Do Igneous Rocks Differ from One Another?     78How Do Magmas Form?     83Where Do Magmas Form?     85Magmatic Differentiation     85Forms of Magmatic Intrusions     88Igneous Activity and Plate Tectonics     91Sedimentation: Rocks Formed by Surface Processes     100Sedimentary Rocks Are Produced by Surface Processes in the Rock Cycle     102Sedimentary Basins: The Sinks for Sediments     106Sedimentary Environments     108Sedimentary Structures     111Burial and Diagenesis: From Sediment to Rock     114Classification of Siliciclastic Sediments and Sedimentary Rocks     116Classification of Chemical and Biological Sediments and Sedimentary Rocks     119Earth Policy: Darwin's Coral Reefs and Atolls     124Metamorphism: Modification of Rocks by Temperature and Pressure      130Metamorphism and the Earth System     132Causes of Metamorphism     133Types of Metamorphism     134Metamorphic Textures     136Regional Metamorphism and Metamorphic Grade     141Plate Tectonics and Metamorphism     144Deformation: Modification of Rocks by Folding and Fracturing     150Mapping Geologic Structure     152How Rocks Deform     154Basic Deformation Structures     156Styles of Continental Deformation     163Unraveling Geologic History     165Earth and Planets Through Geologic TimeClocks in Rocks: Timing the Geologic Record     168Reconstructing Geologic History from the Stratigraphic Record     170Geologic Time Scale: Relative Ages     178Measuring Absolute Time with Radioactive Clocks     180Geologic Time Scale: Absolute Ages     183Timing the Earth System     184Earth Issues: The Grand Canyon Sequence and Regional Correlation of Strata     176Early History of the Terrestrial Planets     188Origin of the Solar System     190Early Earth: Formation of a Layered Planet     192Diversity of the Planets     195What's in a Face? The Age and Complexion of Planetary Surfaces     197Mars Rocks!     204Exploring the Solar System and Beyond     210Evolution of the Continents     214The Tectonics of North America     216Tectonic Provinces Around the World     221How Continents Grow     224How Continents Are Modified     226The Formation of Cratons     235The Deep Structure of Continents     236Geobiology: Life Interacts with the Earth     240The Biosphere as a System     242Microbes: Nature's Tiny Chemists     246Geobiological Events in Earth's History     254Astrobiology: The Search for Extraterrestrial Life     265Earth Issues: The Mother of all Mass Extinctions: Whodunit?     264Internal GeosystemsVolcanoes     270Volcanoes as Geosystems     272Lavas and Other Volcanic Deposits     273Eruptive Styles and Landforms     277Geosystem Interactions     282The Global Pattern of Volcanism     284Volcanism and Human Affairs     288Earth Policy: Mount St. Helens: Dangerous but Predictable     292Earthquakes     296What Is an Earthquake?     298Studying Earthquakes     301Earthquakes and Patterns of Faulting     309Earthquake Destructiveness     313Can Earthquakes Be Predicted?     320Earth Issues: The Great Indian Ocean Tsunami of 2004     312Earth Issues: Seven Steps to Earthquake Safety     319Exploring: Earth's Interior     324Exploring the Interior with Seismic Waves     325Layering and Composition of the Interior     328Earth's Internal Heat and Temperature     332The Three-Dimensional Structure of the Mantle     338Earth's Magnetic Field and the Geodynamo     337Earth Issues: The Uplift of Scandinavia: Nature's Experiment with Isostasy     331Earth Issues: The Geoid: Shape of Planet Earth     338Surficial GeosystemsThe Climate System     346Components of the Climate System     348The Greenhouse Effect     352Climate Variability     355The Carbon Cycle     362Twentieth-Century Warming: Human Fingerprints of Global Change     366Earth Issues: Vostok and GRIP: Ice-Core Drilling in Antarctica and Greenland     358Earth Issues: El Nino: The Wayward Child      360Weathering, Erosion, and Mass Wasting: Interface Between Climate and Tectonics     370Weathering, Erosion, Mass Wasting, and the Rock Cycle     372Controls on Weathering     372Chemical Weathering     373Physical Weathering     378Soil: The Residue of Weathering     381Mass Wasting     384Classification of Mass Movements     388Understanding the Origins of Mass Movements     395The Hydrologic Cycle and Groundwater     400Flows and Reservoirs     402Hydrology and Climate     404The Hydrology of Runoff     406Groundwater     408Water Resources from Major Aquifers     415Erosion by Groundwater     417Water Quality     418Water Deep in the Crust     421Earth Issues: Water Is a Precious Resource: Who Should Get It?     404Earth Issues: When Do Groundwaters Become Nonrenewable Resources?     416Stream Transport: From Mountains to Oceans     426Stream Valleys, Channels, and Floodplains     428Drainage Networks     432Where Do Channels Begin? How Running Water Erodes Solid Rock     435How Stream Waters Flow and Transport Sediment     437Deltas: The Mouths of Rivers     440Streams as Geosystems     443Earth Issues: The Development of Cities on Floodplains     432Winds and Deserts     452Wind as a Flow of Air     454Wind as a Transport Agent     455Wind as an Agent of Erosion     458Wind as a Depositional Agent     460The Desert Environment     464Earth Issues: Martian Dust Storms and Dust Devils     457Coastlines and Ocean Basins     472Basic Differences Between Ocean Basins and Continents     474Coastal Processes     474Shorelines     485Sea Level Change as a Measure of Global Warming     488Continental Margins     491The Deep Oceans     494Ocean Sedimentation     500Earth Policy: The Great New Orleans Flood     480Earth Issues: Preserving Our Beaches     490Glaciers: The Work of Ice     504Ice as a Rock     506How Glaciers Form     508How Glaciers Move     511Glacial Landscapes     515Glaciations and the Climate System     522Earth Issues: Isostasy and Sea-Level Change     524Landscapes: Tectonic and Climate Interaction     530Topography, Elevation, and Relief     532Landforms: Features Sculpted by Erosion and Sedimentation     535Interacting Geosystems Control Landscape     541Models of Landscape Evolution     545Earth Issues: Uplift and Climate Change: A Chicken-and-Egg Dilemma     544Earth Science and SocietyThe Human Impact on Earth's Environment     550Civilization as a Global Geosystem     552Fossil-Fuel Resources     556Alternative Energy Resources     564Global Change     569Welcome to the Anthropocene: A New Geologic Epoch     574Earth System Engineering and Management     575Earth Policy: Subsurface Toxic and Nuclear Waste Contamination     566Earth Policy: The Kyoto Accords and the Politics of Climate Change     577Conversion Factors     AP-1Numerical Data Pertaining to Earth     AP-2Chemical Reactions     AP-3Properties of the Most Common Minerals of Earth's Crust     AP-4Glossary     GL-1Suggested Readings     SR-1Index     I-1