Stereographic Projection Techniques for Geologists and Civil Engineers

Richard J. Lisle, Peter R. Leyshon

• Publisher: Cambridge University Press
• Year: 2004
• Print ISBN: 9780521535823
• eBook ISBN: 9781139927697
• Edition: 2
• Topic: Physical Sciences
• Subtopic: Geology & Earth Sciences

The stereographic projection is an essential tool in the fields of structural geology and geotechnics, which allows three-dimensional orientation data to be represented and manipulated. This book has been designed to make the subject as accessible as possible. It gives a straightforward and simple introduction to the subject and, by means of examples, illustrations and exercises, encourages the student to visualise the problems in three dimensions. Students of all levels will be able to work through the book and come away with a clear understanding of how to apply these vital techniques. This revised edition contains additional material on geotechnical applications, improved illustrations and links to useful web resources and software programs. It will provide students of geology, rock mechanics, geotechnical and civil engineering with an indispensable guide to the analysis and interpretation of field orientation data.

Table of contents

• Cover
• Half Title
• Title Page
• Copyright
• Contents
• Preface
• Acknowledgements
• 1 Geological structures of planar type
• 2 Measuring and recording the orientation of planar structures
• 3 Geological structures of linear type
• 4 Measuring and recording the orientation of lines
• 5 Why do we need projections?
• 6 Idea of stereographic projection
• 7 Approximate method of plotting lines and planes
• 8 Exercises 1
• 9 The stereographic net
• 10 Precise method for plotting planes. Great circles and poles
• 11 Precise methods for plotting lines 1. Where the plunge of the line is known
• 12 Precise methods for plotting lines 2. Where the line is known from its pitch
• 13 The intersection of two planes
• 14 Plane containing two lines
• 15 Apparent dip
• 16 The angle between two lines
• 17 The angle between two planes
• 18 The plane that bisects the angle between two planes
• 19 Projecting a line onto a plane
• 20 Stereographic and equal-area projections
• 21 The polar net
• 22 Analysing folds 1. Cylindricity and plunge of axis
• 23 Analysing folds 2. Inter-limb angle and axial surface
• 24 Analysing folds 3. Style of folding
• 25 Analysing folds 4. The orientation of folds
• 26 Folds and cleavage
• 27 Analysing folds with cleavage
• 28 Faults 1. Calculating net slip
• 29 Faults 2. Estimating stress directions
• 30 Cones/small circles
• 31 Plotting a cone
• 32 Rotations about a horizontal axis
• 33 Example of rotation about a horizontal axis. Restoration of tilt of beds
• 34 Example of rotation. Restoring palaeocurrents
• 35 Rotation about an inclined axis
• 36 Example of rotation about an inclined axis. Borehole data
• 37 Density contouring on stereograms
• 38 Superposed folding 1
• 39 Superposed folding 2. Sub-area concept
• 40 Example of analysis of folds. Bristol area
• 41 Geometrical analysis of folds. Examples from SW England
• 42 Example of analysis of jointing. Glamorgan coast
• 43 Geotechnical applications. Rock slope stability
• 44 Assessing plane failure. Frictional resistance
• 45 Assessing plane failure. Daylighting
• 46 Assessing wedge failure
• 47 Exercises 2
• 48 Solutions to exercises
• Appendix 1 Stereographic (Wulff) equatorial net
• Appendix 2 Equal-area (Lambert/Schmidt) equatorial net
• Appendix 3 Equal-area polar net
• Appendix 4 Kalsbeek counting net
• Appendix 5 Classification chart for fold orientations
• Appendix 6 Some useful formulae
• Appendix 7 Alternative method of plotting planes and lines
• Availability of computer programs for plotting stereograms
• Further reading
• Index