Download Geological Structure Map of Robben Island

Geological Structure Map of Robben Island
C. D. Rowe, N. R. Backeberg, T. van Rensburg, S. A. Maclennan, C. Faber, C. Curtis & P. Viglietti
University of Cape Town Department of Geological Sciences
Legend
1 000 m
B
Bedding orientation
20
15/315
76
20
90 18
10
46
32
76
15
15
52
86
87
32
12
Overturned anticline with plunge direction and angle
16
30
30
06
28
Thrust fault, teeth on upthrown side
Wrench fault with sense of rotation
f
f
10
Adjacent but oppositely plunging folds
separated by cryptic bedding-parallel wrench
surface. Bedding is continuous from each axis
out to the wrench fault, the position of which
is restricted to a 1.5m-wide limb-parallel zone
with minor bedding
deflection and no noticeable
20 22
brittle damage zone on either
side. Wreck of the 60m Sea
Challenger for scale.
69
Anticline with plunge direction and angle
13
50
12/124
Pressure solution cleavage orientation
15 Syncline with plunge direction and angle
20
36
14
82
76
16
16
90
80
36 80
28
52
46
18
31
Fault; approximate location (sense of shear unknown)
88
52
14
36
North
29
87
60
65
68
46
65
68
12
43
15
40
49
59
65
32
56
15
78
C
Fold axis (n=18)
15
10
64
76
30
56
40
64
62
A
48
74 86 39
65
85
30
86
33
29
19 43 54
4883
35
86
85
87 68
72
65
15/122
58
f
52
15 10
30
78
Cleavage fanning in meso-scale
cylindrical fold. Stereonet shows
π-diagram solution for fold axis
from bedding measurements. Star
symbol = fold axis (15/122).
49
78
72
20
87
D
18
64
WNW
04
ESE
N
down
08
61
36
80
Block diagram shows the sense of
rotation on a typical Mode II fault
on the west coast of Robben Island
81
12
65
53
66
10
09
19
24
16
13
41
65
f
14
Rowe, C. et al. (2010) Structural Geology of Robben
Island: Implications for the Tectonic Environment
of Saldanian Deformation, South African Journal of
Geology, v. 113.1 p. 57-72