Stratigraphy: A Modern Synthesis

Description

The updated textbook is intended to serve as an advanced and detailed treatment of the evolution of the subject of stratigraphy from its disparate beginnings as separate studies of sedimentology, lithostratigraphy, chronostratigraphy, etc., into a modern integrated discipline in which all components are necessary. There is a historical introduction, which now includes information about the timeline of the evolution of the components of modern stratigraphy. The elements of the various components (facies analysis, sequence stratigraphy, mapping methods, chronostratigraphic methods, etc.) are outlined, and a chapter discussing the modern synthesis is included near the end of the book, which closes with a discussion of future research trends in the study of time as preserved in the stratigraphic record. Preface Revision History References Contents 1 The Scope of Modern Stratigraphy Abstract 1.1 The Importance of Stratigraphy 1.2 The Evolution of “Sophisticated Stratigraphy” 1.2.1 Beginnings (Nineteenth Century) 1.2.2 Cyclic Sedimentation (1932–1968) 1.2.3 Basin Analysis and the Big Picture (1948–1977) 1.2.4 The Meaning of “Facies” (1949–1973) 1.2.5 Fluid Hydraulics and Sedimentary Structures (1953–1976) 1.2.6 Early Studies of Modern Environments (1954–1972) 1.2.7 Facies-Model Concept (1959–2010) 1.2.8 The Impact of the Plate-Tectonics Revolution on Basin Studies (1959–1988) 1.2.9 Unconformities and the Issue of Time in Stratigraphy (1909–1970) 1.2.10 Sequences and Seismic Stratigraphy (1963–1977) 1.2.11 Architectural Elements: Sedimentology in Two and Three Dimensions (1983–1990) 1.2.12 Sequence Stratigraphy (1986–1990) 1.2.13 Reconciling Facies Models with Sequence Stratigraphy (1990) 1.2.14 The Full Flowering of Modern Sequence-Stratigraphic Methods 1.2.15 Stratigraphy: The Modern Synthesis 1.3 Time in Stratigraphy 1.4 Types of Project and Data Problems 1.4.1 Regional Surface Stratigraphic Mapping Project 1.4.2 Local Stratigraphic-Sedimentologic Mapping Project 1.4.3 Regional Subsurface Mapping Project 1.4.4 Local Subsurface Mapping Project 1.5 Summary of Research and Reporting Procedures References 2 The Stratigraphic-Sedimentologic Data Base Abstract 2.1 Introduction 2.2 Describing Surface Stratigraphic Sections 2.2.1 Methods of Measuring and Recording the Data 2.2.1.1 Vertical Stratigraphic Sections 2.2.1.2 The Construction of Lateral Profiles 2.2.2 Types of Field Observation 2.2.2.1 Subdivision of the Section into Descriptive Units 2.2.2.2 Lithology and Grain Size 2.2.2.3 Porosity 2.2.2.4 Color 2.2.2.5 Bedding 2.2.2.6 Inorganic Sedimentary Structures 2.2.2.7 Sedimentary Structures Produced by Hydrodynamic Erosion of the Bed 2.2.2.8 Liquefaction, Load and Fluid Loss Structures 2.2.2.9 Fossils 2.2.2.10 Biogenic Sedimentary Structures 2.2.3 Sampling Plan 2.2.3.1 Illustrative Samples 2.2.3.2 Petrographic Samples 2.2.3.3 Biostratigraphic Samples 2.2.4 Plotting the Section 2.3 Describing Subsurface Stratigraphic Sections 2.3.1 Methods of Measuring and Recording the Data 2.3.1.1 Examination of Well Cuttings 2.3.1.2 Examination of Core 2.3.2 Types of Cutting and Core Observation 2.3.2.1 Subdivision of the Section into Descriptive Units 2.3.2.2 Lithology and Grain Size 2.3.2.3 Porosity 2.3.2.4 Color 2.3.2.5 Bedding 2.3.2.6 Sedimentary Structures 2.3.2.7 Fossils 2.3.2.8 Biogenic Sedimentary Structures 2.3.3 Sampling Plan 2.3.4 Plotting the Section 2.4 Petrophysical Logs 2.4.1 Gamma-Ray Log (GR) 2.4.2 Spontaneous Potential Log (SP) 2.4.3 Resistivity Logs 2.4.4 Sonic Log 2.4.5 Formation Density Log 2.4.6 Neutron Log 2.4.7 Crossplots 2.4.8 Integrating Cores and Wireline Logs References 3 Facies Analysis Abstract 3.1 Introduction 3.2 The Meaning of Facies 3.3 Recognition and Definition of Facies Types 3.3.1 Philosophy and Methods 3.3.2 Field Examples of Facies Schemes 3.3.3 Establishing a Facies Scheme 3.3.4 Facies Architecture 3.4 Facies Associations and Models 3.4.1 The Association and Ordering of Facies 3.4.2 The Theory of Facies Models 3.4.3 The Present as the Key to the Past, and Vice Versa 3.4.4 To Classify and Codify, or Not? 3.4.5 Facies Analysis and Sequence Stratigraphy 3.5 Review of Environmental Criteria 3.5.1 Grain Size and Texture 3.5.2 Petrology 3.5.3 Bedding 3.5.4 Hydrodynamic Sedimentary Structures 3.5.4.1 The Flow-Regime Concept 3.5.4.2 Bedform Preservation 3.5.4.3 Bedforms and Crossbedding in Gravels 3.5.4.4 Structures Formed by Reversing (Tidal) Currents 3.5.4.5 Structures Formed by Oscillating Currents (Waves) 3.5.4.6 Storm Sedimentation and Geostrophic Flow 3.5.4.7 Eolian Bedforms 3.5.5 Sediment Gravity Flows 3.5.5.1 Debris Flow 3.5.5.2 Grain Flow 3.5.5.3 Liquified/fluidized Flow 3.5.5.4 Turbidity Current 3.5.6 Sedimentary Structures Produced by Hydrodynamic Erosion of the Bed 3.5.7 Liquefaction, Load and Fluid Loss Structures 3.5.8 Paleoecology of Body Fossils 3.5.9 Ichnology 3.5.10 Vertical Profiles 3.5.11 Architectural Elements and Bounding Surfaces 3.5.11.1 Architectural Scale and Bounding Surface Hierarchies 3.5.11.2 Architectural Elements 3.6 Conclusions and Scale Considerations References 4 Facies Models Abstract 4.1 Introduction 4.2 Clastic Environments 4.2.1 Fluvial Environments 4.2.2 Eolian Environments 4.2.3 Lacustrine Environments 4.2.4 Glacial Environments 4.2.5 Coastal Wave- and Tide-Dominated Environments 4.2.6 Deltas 4.2.7 Estuaries 4.2.8 Continental Shelf Environment 4.2.9 Continental Slope and Deep Basin Environment 4.3 Carbonate Environments 4.3.1 Conditions of Carbonate Sedimentation 4.3.2 Platforms and Reefs 4.3.3 Tidal Sedimentation 4.3.4 Carbonate Slopes 4.4 Evaporites References 5 Sequence Stratigraphy Abstract 5.1 Introduction 5.2 Elements of the Model 5.2.1 Accommodation and Supply 5.2.2 Stratigraphic Architecture 5.2.3 Depositional Systems and Systems Tracts 5.3 Sequence Models in Clastic and Carbonate Settings 5.3.1 Marine Clastic Depositional Systems and Systems Tracts 5.3.2 Nonmarine Depositional Systems 5.3.3 Carbonate Depositional Systems 5.3.3.1 Breaks in Sedimentation in Carbonate Environments 5.3.3.2 Platform Carbonates: Catch-Up Versus Keep-Up 5.4 Sequence Hierarchies 5.5 Driving Mechanisms 5.6 Conclusions References 6 Basin Mapping Methods Abstract 6.1 Introduction 6.2 Stratigraphic Mapping with Petrophysical Logs 6.2.1 Log Shape and Electrofacies 6.2.2 Examples of Stratigraphic Reconstructions 6.2.3 Problems and Solutions 6.3 Seismic Stratigraphy 6.3.1 The Nature of the Seismic Record 6.3.2 Constructing Regional Stratigraphies 6.3.3 Seismic Facies 6.3.4 Seismic Geomorphology 6.4 Directional Drilling and Geosteering 6.5 Older Methods: Isopleth Contouring 6.6 Mapping on the Basis of Detrital Composition 6.6.1 Clastic Petrofacies 6.6.2 Provenance Studies Using Detrital Zircons 6.6.3 Chemostratigraphy 6.7 Paleocurrent Analysis 6.7.1 Introduction 6.7.2 Types of Paleocurrent Indicators 6.7.3 Data Collection and Processing 6.7.4 The Bedform Hierarchy 6.7.5 Environment and Paleoslope Interpretations References 7 Stratigraphy: The Modern Synthesis 7.1 Introduction 7.2 Types of Stratigraphic Unit 7.3 The Six Steps Involved in Dating and Correlation 7.4 Lithostratigraphy 7.4.1 Types of Lithostratigraphic Units and Their Definition 7.4.2 The Names of Lithostratigraphic Units 7.5 Biostratigraphy 7.5.1 The Nature of the Biostratigraphic Record 7.5.2 Biochronology: Zones and Datums 7.5.3 Diachroneity of the Biostratigraphic Record 7.5.4 Quantitative Methods in Biochronology 7.6 Unconformities and Unconformity-Bounded Units 7.7 The Development of Formal Definitions for Sequence Stratigraphy 7.8 Chronostratigraphy and Geochronometry 7.8.1 The Emergence of Modern Methods 7.8.2 Determining the Numerical (“Absolute”) Age of a Stratigraphic Horizon 7.8.3 Stages and Boundaries 7.8.4 Event Stratigraphy 7.8.5 Absolute Ages: Their Accuracy and Precision 7.8.6 The Current State of the Global Stratigraphic Sections and Points (GSSP) Concept and Standardization of the Chronostratigraphic Scale 7.8.7 Cyclostratigraphy and Astrochronology 7.9 Stratigraphy Reflects Changing Earth Environments References 8 The Future of Time Abstract 8.1 Introduction 8.2 Where We Are Now and How We Got Here 8.3 A Natural Hierarchy of Sedimentary Processes 8.4 Sedimentation Rates 8.5 The Fractal-Like Character of Sedimentary Accumulation 8.6 Apparent Anomalies of High Sedimentation Rate Versus Slow Rate of Accommodation Generation 8.7 Accommodation and Preservation 8.7.1 Preservation at a Scale of Seconds to Months 8.7.2 Preservation at a Scale of Years to Thousands of Years 8.7.3 Preservation at the Scale of Tens of Thousands to Hundreds of Thousands of years 8.7.4 Preservation at the Scale of Millions of years 8.8 The Stratigraphy Machine 8.9 Implications of Missing Time for Modern Stratigraphic Methods 8.9.1 Sequence Stratigraphy 8.9.2 Implications for Stratigraphic Continuity, the Concept of Correlation and the Principal of the GSSP 8.9.3 Discussion 8.10 The Future of Conventional Chronostratigraphy 8.10.1 Current Examples of Outstanding Work 8.10.2 The Use of Wheeler Diagrams 8.10.3 Improving Accuracy and Precision 8.11 Accounting for Missing Time 8.11.1 Constructing Wheeler Diagrams for Selected Examples 8.11.2 A Well-Documented Quaternary Example 8.11.3 The Example of the Mesaverde Group, Utah 8.11.4 High-Resolution Stratigraphy 8.11.5 Cyclostratigraphy and Astrochronology 8.11.6 Conclusions References Author Index Subject Index