Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Stereographic Projection Techniques for Geologists and Civil Engineers
- 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
8 - Exercises 1
from Stereographic Projection Techniques for Geologists and Civil Engineers
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Stereographic Projection Techniques for Geologists and Civil Engineers
- 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
Summary
1 Plot the measurements of lines and planes given on the left of Figure 8:
(a) on the maps with the appropriate symbol and
(b) on sketch stereograms.
2 Convert the planes and lines plotted on the stereogram in the right hand column of Figure 8 into:
(a) map symbols and
(b) approximate numerical values.
3 Using your experiences in Question 1, answer the following.
(a) How do the great circles of steeply dipping planes differ from the great circles of planes with low dips?
(b) How does the plotted position of a steeply plunging line differ from that of a gently plunging one?
(c) How could the strike direction of a plane be deduced from its great circle on a stereogram?
4 A bedding plane strikes 080° and dips 60S.
(a) Draw an appropriate map symbol and a sketch stereogram for this plane.
(b) What are the angle of plunge and direction of plunge of the normal to the plane 080/60S? (The normal is a line perpendicular to a plane.)
(c) Plot the plane's normal as a dot on the sketch stereogram.
5 A plane has an orientation 124/40SW.
(a) Draw this dipping plane on a sketch stereogram in the manner illustrated on p. 15.
(b) Plot on this sketch stereogram the following:
(i) the strike line (S),
(ii) a line (T) in the plane which plunges in direction 180°,
[…]
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- Publisher: Cambridge University PressPrint publication year: 2004