An Integrated Framework for Structural Geology - Basil Tikoff

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Résumé :

Acknowledgements xvii

Website xix

1 A Framework for Structural Geology 1

1.1 Introduction 1

1.1.1 Deformation 1

1.1.2 Empirical vs. Theoretical Approaches 1

1.1.3 Continuum Mechanics and its Applicability to Structural Geology 6

1.1.4 How to use this Book 6

References 8

2 Structures Produced by Deformation 10

2.1 Geological Structures 10

2.1.1 Structural Fabrics 10

2.1.2 Folds and Boudinage 12

2.1.3 Fractures and Stylolites 15

2.1.4 Faults and Fault Zones 17

2.1.5 Shear Zones 22

2.2 Additional Considerations 25

3 Microstructures 26

3.1 Introduction 26

3.1.1 Overview 26

3.1.2 Framework 27

3.1.3 Imaging of Microstructures 27

3.2 Fractures 28

3.3 Fault Rocks 30

3.4 Overgrowths, Pressure Shadows and Fringes, and Veins 33

3.5 Indenting, Truncating and Interpenetrating Grain Contacts, Strain Caps, and Stylolites 37

3.6 Aligned Grain Boundaries, T Grain Boundaries, and Foam Texture 38

3.7 Undulose Extinction, Subgrains, Deformation and Kink Bands, Deformation Lamellae, Grain Boundary Bulges, and Core-and-Mantle Microstructure 40

3.8 Deformation Twins 43

3.9 Grain Shape Fabrics, Ribbon Grains, and Gneissic Banding 43

3.10 Porphyroblasts 47

3.11 Crystallographic Fabrics (Crystallographic Preferred Orientations) 49

3.12 Shear Sense Indicators, Mylonites, and Porphyroclasts 49

3.12.1 Asymmetric Pressure Shadows and Fringes 53

3.12.2 Foliation Obliquity and Curvature 55

3.12.3 SC, SC?, and SCC? Fabrics 55

3.12.4 Porphyroclast Systems 56

3.12.5 Precautions with Shear Sense Determination 59

3.13 Collecting Oriented Samples and Relating Sample to Geographic Frames of Reference 60

References 65

4 Displacements 66

4.1 Overview 66

4.2 Chapter Organization 66

4A Displacements: Conceptual Foundation 67

4A.1 Specifying Displacements or Individual Particles 67

4A.1.1 Basic Ideas 67

4A.1.2 Geological Example 69

4A.2 Particle Paths and Velocities 70

4A.2.1 Particle Paths 70

4A.2.2 Velocities 71

4A.3 Displacements of Collections of Particles - Displacement Fields 74

4A.3.1 Displacement Fields 74

4A.3.2 Uniform vs. Nonuniform and Distributed vs. Discrete Displacement Fields 76

4A.3.3 Classes of Displacement Fields 77

4A.4 Components of Displacement Fields: Translation, Rotation, and Pure Strain 79

4A.5 Idealized, Two-Dimensional Displacement Fields 85

4A.5.1 Simple Shear 87

4A.5.2 Pure Shear 88

4A.6 Idealized, Three-Dimensional Displacement Fields 89

4A.7 Summary 90

4B Displacements: Comprehensive Treatment 90

4B.1 Specifying Displacements for Individual Particles 90

4B.1.1 Defining Vector Quantities 90

4B.1.2 Types of Vectors 92

4B.1.3 Relating Position and Displacement Vectors 94

4B.1.4 Characterizing Vector Quantities 95

4B.2 Particle Paths and Velocities 97

4B.2.1 Incremental Displacements for Particles 97

4B.2.2 Particle Paths and Movement Histories 98

4b.2.3 Dated Particle Paths, Instantaneous Movement Directions, and Velocities 99

4B.3 Displacements of Collections of Particles - Displacement Fields 101

4B.3.1 Concept of a Displacement Field 101

4B.3.2 Field Quantities 103

4b.3.3 Gradients of the Displacement Field: Discrete and Distributed Deformation 103

4B.3.4 Idealized Versus True Gradients of the Displacement Field 104

4B.4 The Displacement Gradient Tensor - Relating Position and Displacement Vectors...

Biographie:
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Sommaire:

Steven Wojtal is Professor of Geoscience at Oberlin College in Oberlin, Ohio, United States.

Tom Blenkinsop is Professor in Earth Science at Cardiff University, United Kingdom.

Basil Tikoff is Professor of Geoscience at the University of Wisconsin-Madison, United States....