Drawing Geological Structures

Despite the modern dominance of computer graphics programs and digital cameras, the ability todraw geological structures manually remains a necessity in academic geology and beyond. Drawings serve for quick and simple documentation in the field or at the microscope. They can be applied as a language of their own as well as be adapted to suit specific requirements. Moreover, geological drawing improves observational ability and contributes to the understanding of geological structures and structure-forming processes. Geological drawing is assisted scientific thinking. Drawing Geological Structures provides undergraduate as well as graduate and practicing geologists with a thorough, step-by-step practical guide to the art of geological drawing. Beginning with the basics, the book covers thin sections, sample sections, samples and geological stereograms. The chapters provide examples of how drawings evolve and are complemented by exercises, allowing the reader to practice their drawing prior to going out into the field or working at the microscope. Users of this unique guide will develop their knowledge and technical vocabulary whilst also improving their drawing skills.

Auteur

Jörn H. Kruhl is retired professor of geology at Technische Universität München, Germany. He received his Dr. rer. nat. from Rheinische Friedrich-Wilhelms-Universität Bonn and held appointments in research and teaching at universities in Mainz, Salzburg, Berlin and Frankfurt/M. For decades, he worked on rock structures in numerous regions and orogens, from macro to micro, in the field and at the microscope.

Contenu
About the Author vii

Preface ix

1 Introduction 1

1.1 Why Do We Need Drawings? 5

1.2 The Tools 11

1.3 Sizes of Drawings 12

1.4 Geological Versus Artistic Drawing 13

1.5 Drawing With Symbols 15

1.6 Realistic Drawing 21

1.7 The Fractal Geometry of Geological Fabrics 26

1.8 Basic Rules of Geological Drawing 29

References 30

2 Rock Thin Sections 33

2.1 Drawing as a Form of Microscopy 35

2.2 Drawing with Various Tools 35

2.3 Foundations of Thin-Section Drawing 36

2.4 Minerals and Their Characteristic Fabrics Under the Microscope 41

2.5 Sketches for Fast Documentation 52

2.6 Development of Precise Thin-Section Drawings 60

2.7 Digital Reworking of Manual Thin-Section Drawings 82

2.8 Digital Drawing 83

Summary 90

References 93

3 Specimen Sections 95

3.1 The Geological Message of a Drawing 95

3.2 Schematic Representation of Minerals 97

3.3 Schematizing Rocks and their Structures 100

3.4 Development of Drawings 104

3.5 Illustration on Different Scales 107

3.6 Detailed Drawings of Sample Cuts 110

Summary 116

4 Drawing Rock Structures in Three Dimensions 117

4.1 Foundations 118

4.2 The Development of Schematic 3D Drawings 125

4.3 Field Drawing 156

4.4 Digital Processing 169

4.5 Rules of Labeling 172

Summary 174

References 177

5 Geological Stereograms 179

5.1 Foundations 179

5.2 Orientation and Extension 181

5.3 Additions and Labeling 189

5.4 Digital Processing 193

Summary 195

References 196

6 Solutions 199

Index 207