Page 239 - Global Tectonics

Arava
valley
Arava Fault
NW SE
0 3.7 3.7 3.5 4.0 3.1 3.1 4.4 0
5 5.1 5.1 6.1 6.1 5 8.0
10 6.2 6.2 Seismic 10 7.5
7.0
15
6.5
basement
15
Depth (km) 20 6.4 6.7 6.4 Lower 6.7 6.3 20 Depth (km) 6.0
5.5
6.7
25
5.0
25
30
4.0
7.9 6.7 crust 6.7 30 4.5
35 35 3.5
40 7.9 Mantle 7.9 40 3.0
2.5
45 45 2.0
50 100 150 200 250 300 P Velocity (km s )
-1
Distance (km)
Figure 8.11 P-wave velocity model of the crust and mantle below the Arava Fault within the southern segment of the
Dead Sea Transform (image provided by M. Weber and modified from the DESERT Group, 2004, with permission from

Blackwell Publishing). Profile location is shown in Fig. 8.3a. Vertical exaggeration is 2 : 1. Triangles indicate shot points
−1
along a wide angle seismic reflection and refraction survey used to obtain the velocities (km s ). Hatched area near

crust–mantle boundary represents zone of strong lower crustal reflections. The boundaries and P-wave velocities

located northwest of the fault are from Ginzburg et al. (1979a,b) and Makris et al. (1983). Those to the southeast of the
fault are based on El-Isa et al. (1987a,b).
t = 0 Myr
W Arava Fault Ductile E (d)
simultaneously acting proceses < 4 km extension (c)
Brittle
Brittle
Ductile

Brittle

t = 17 Myr Ductile (b)
W Arava E (a)

105 km
Fault
Sediments

Crust

Figure 8.12 Sketches showing the processes involved in producing the crustal section shown in Fig. 8.11 (image
provided by J. Mechie and modified from the DESERT Group, 2004, with permission from Blackwell Publishing). (a)

Crustal structure at ∼17 Myr, before initiation of strike-slip motion. (b) Strike-slip displacement of ∼105 km results in
significantly different structure east and west of the Arava Fault. (c) Minor (∼4 km) of extension results in subsidence

and flexure of the western block and uplift of the eastern block. Moho shows a similar deflection. (d) Erosion and
sedimentation produces present structure. Note that processes (b–d) act simultaneously.