Structural Geology (Geol 4013/6013)
Lab Exercise 2
Name: _________________
Questions: (35 pts), Map 2.7: (20 pts); shear strain plot (15 pts), Map/section 23: (30 pts)
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Part I:
o Lines and Intersecting Planes
o Planes and Topography
o Geological Map, completion of
maps
Part II: Deformation
Attachments:
Figure 4.15
Figure 4.16
Map 2.7
Figure2.18
Figure 11.33 on page 301 with points plotted on it
Map 23
Study Chapter 4, and 11 of the lab Manual by Donal M. Ragan: “Structural Geology, an Introduction to
Geometrical Techniques”, 4th Edition.
Chapter 4. Do the following problems from the “Exercises 4.9” on page 87 of the Lab Manual:
Attach all your work (maps)!
Chapter 4, Problem 1 (Page 87): Figure 4.15 is attached! (Read Section 4.3 (Page 76) as a guide!)
Draw two structural contours for both the top and bottom contacts of the gray units for map (Fig.
4.15a) and map (Fig. 4.15b) at 750m and 740 m (i.e., each figure should have 4 lines!).
1. What is the strike of the gray unit of Figure 4.15a in the azimuth format?
a. 135
b. 281
c. 079
d. 020
e. 180
2. What is the strike of the gray unit of Figure 4.15a in the quadrant format?
a. N65W
b. S12E
c. S79E
d. N20W
e. N20E
3. What is the dip of the gray unit of Figure 4.15a?
a. 78NW
b. 21SW
c. 22NW
d. 20NE
e. 40SE
4. What is the attitude of the gray unit of Figure 4.15b in the azimuth formats?
a. 259, 35NW b. 035, 89NW c. 281, 56NE d. 098, 18SW e. 128, 56SW
5. What is the attitude of the gray unit of Figure 4.15b in the quadrant formats?
a. S59E, 35NE b. N35E, 35NW c. N82W, 35NW d. N29W, 56SW e. S79W, 35NW
6. What is the vertical thickness (tv), in meter, of the gray unit in Figure 4.15a?
a. 16m
b. 69m
c. 30m
d. 78m
e. 62m
7. What is the approximate true (normal) thickness (t or tn), in meter, of the gray unit in Figure
4.15a? Note: tn = tv cos 
a. 28m
b. 49m
c. 13m
d. 148m
e. 66m
8. What is the vertical thickness (tv), in meter, of the gray unit in Figure 4.15b?
a. 6m
b. 39m
c. 20m
d. 98m
e. 60m
9. What is the approximate true (normal) thickness (t or tn), in meter, of the gray unit in Figure
4.15b? Note: tn = tv cos 
a. 28m
b. 49m
c. 13m
d. 148m
e. 68m
Structural Geology (Geol 4013/6013)
Lab 2. Page 1
Chapter 4, Problem 2 (Page 87). Figure 4.16 is attached! Topic: completion of a map
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Read the instructions for this problem and then complete the geological map of Figure 4.16 by
drawing all the contacts of all units! Note: for the lower Triassic unit exposed at point A, you
need to draw the structural contours along the N70W direction at 10 m intervals (v). Use
trigonometry and find the horizontal spacing (x) between these contours on the map
x =?
using the true dip ( = 25 SW).
tan = v/x
tan 25 = 10/x find the horizontal spacing (x).
Use the scale of the map for and draw the structural Contours. Label them. V =10

Intersect the structural contour of a given value (i.e., at specific elevation) with the topographic
contour of the same value.
Trace these points of intersection. These will define the surface exposure.
Do this for the top and for the bottom of the unit.
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10. What is the orientation of the unit exposed at point D?
a. Vertical
b. N90E, 00 c. 270, 90
d. horizontal
e. 000, 90
11. What is the attitude of the diabase dike at B in the azimuth format?
a. N80E, 40SE b. 020, 90 c. 090, 20N d. 020, 20NE e. 080, 20NW
12. What is the approximate minimum true thickness of the Tertiary rocks?
a. 35 m
b. 10 m
c. 80 m
d. 15 m
e. cannot be determined
Examine the attached Map (2.7) and answer the following questions:
13. What is the orientation of the units?
a. vertical b. 000, 90 c. 090, 90 d. 090, 30W
e. horizontal
14. What is the approximate normal (true) thickness of the ‘Upper Lias’ unit?
a. 40 m
b. 120 m
c. 10 m
d. 89 m
e. cannot be determined
15. What is the minimum thickness of the ‘Inferior Oolite’ unit?
a. 140 m
b. 60 m
c. 100 m d. 10 m
e. cannot be determined
16. What is the approximate normal (true) thickness of the ‘Middle Lias’ unit?
a. 12 m
b. 140 m
c. 34 m
d. 70 m
e. cannot be determined
/20 pts
Draw a cross section along the northern edge of this map
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The topographic map of Figure 2.18 (attached) exposes a thin limestone outcrop. The attitude of the
bedding in the limestone is given on the map (with the strike and dip symbol). Draw the structural
contours where topographic contours intersect the contacts. Neatly label the structural contours with
elevation values. Extend the thin limestone bed throughout the map area, using the structural
contours.
Structural Geology (Geol 4013/6013)
Lab 2. Page 2
17. What is the strike of the limestone bed?
a. 000 b. 050 c. 210 d. 070 e. 130
18. What is the true dip of the limestone bed?
a. 10SW b. 20NE c. 40SW d. 30NW e. 60SW
Part II: Deformation - Chapter 11, Page 300.
11.8 Exercises, Problem 3. Figure 11.33 on page 301 (attached on the graph paper!) shows the trace of
foliation across a shear zone. Points A through I are the positions of outcrops in the shear zone.
The shear zone is 36.5 mm wide (w), and is symmetric relative to the middle line.
Use a protractor and measure the angle () between the trace of the foliation at each point and the line
that defines the boundary of the shear zone (record the distance as w). Put your values in the table
below. Hint: draw long tangents to each foliation trace at each point and measure the angle () from
the shear zone boundary.
Calculate the shear strain ( = 2/tan 2). Fill in the following table:
Given w and points below
Distance (w), mm
Point
0
I
3
H
10
G
14
F
18
E
22
D
25
C
32
B
36.5
A
Complete the following cells for  and 
Angle 
 = 2/tan 2
Average shear strain ’ = /9 =
19. What is the shear strain at point E?
a. 0.10 b. 0.80 c. 1.12 d. 5.5 e. 0.01
20. At which point is the shear strain maximum?
a. D
b. H
c. G
d. E
e. A
21. At which point is the shear strain minimum?
b. D
b. H
c. G
d. E
e. A
22. What is the average shear strain ’ = /9 for the nine points?
a. 5.5
b. 3.5
c. 8.4 d. 1.84 e. 2.56
/15
Plot  against distance (w) on the attached graph paper. Attach the plot for credit!
Scale: 1cm = 1  unit
23. What is the amount of displacement (D) across the shear zone by counting the area
(squares) under the curve of your plot of  against w?
a. 2 squares or 20 units b. 6.5 squares or 66 units c. 12 squares or 110 units
d. 4 squares or 24 units e. 10 squares or 100 units
24. What is the amount of displacement (D in mm) across the shear zone?
Structural Geology (Geol 4013/6013)
Lab 2. Page 3
Use the following equations (integral of the shear strain across the shear zone):
D =   w = ’w (where ’ is the average shear strain and w runs from 0 to 36.5 mm)
a. 34.50 mm b. 16.25 mm c. 78.50 mm d. 66.24 mm e. 29.50 mm
Part III: Geological map and cross section:
Map 23 (attached ) shows a geological map of an area exposing different units.
The attitudes of the units are given. Scale: 1cm = 400 m
/30 pts Draw a precise structural cross section where indicated, using the
topographic profile provided. No vertical exaggeration!
Attach your section for credit
25. What is the approximate orientation of the fault?
a. Horizontal b. 347, 00 c. 000, 00 d. 126, 00 e. N13W, 90
26. What is the relative age of the fault?
a. Younger than breccia ‘p’ b. older than ‘p’ c. older than tilting
d. Synchronous with folding e. uncertain
27. Units ‘p’ and ‘r’ are conformable.
a. True b. false
28. The contacts between ‘p’ and f is unconformable
a. True b. false
29. Units ‘q’ and ‘r’ are deformed (tilted)
a. True b. false
30. The fold is
a. plunging north
b. plunging south
c. plunging east
d. doubly plunging
e. plunging west
31. It is possible that the fold and fault formed at the same time
a. True b. False
32. Which is older? The unconformity between ‘p’ and ‘q’ or tilting of ‘r’?
a. unconformity is older
b. tilting is older c. tilting is younger
d. unconformity is younger e. none of the these is correct
33. Tilting of the units is the youngest event. The fault, however, could be
post-tilt or post-fold.
a. True
b. False
34. Folding of the units ‘a’ through ‘f’ is younger than the deposition of q and r.
a. True
b. False
35. Deposition of the breccia, P, is younger than folding.
a. True
b. False
Structural Geology (Geol 4013/6013)
Lab 2. Page 4
Write the ordered sequence of events in the following table. Include deposition, folding, fauting,
erosion, and tilting as event.
Youngest
6
5
4
3
2
Oldest
1
Structural Geology (Geol 4013/6013)
Lab 2. Page 5