Page 209 - Global Tectonics

CONTINENTAL RIFTS AND RIFTED MARGINS 195

COB
(a) NW SE
0 1.95 2.45
5.15 5.0 5.2 4.5 6.0 6.0
10 6.9 6.7 6.0 6.4
7.2 6.4 6.4
7.2
8.1 8.2 6.8
km 20 6.8
SDR 8.2 8.2
30
OCEAN–CONTINENT TRANSITION ZONE
V.E.= 3x
40
0 50 100 150 200 250 300 350 km

(b)
0 50 100 150 200 250 300 350 400 km
150
Gravity anomaly
100
50
mGal 0
50 observed
calculated
100
150

Cenozoic and Cretaceous
(c) glacial sediment COB Volcanic layers sediment
NW and SDR SE
0
2050 2200 2400 2450
2500
2500
2550
2450
2450 2500 2550
2450
2550
2650
2650
2800 2650 2550 2600 Continental
2900
2900
10 2900 2850 crust
3000
3000
3000 2790
2790
Oceanic crust 3200 2900
2900
2900
km 20
High velocity
lower crustal body
30
High density
continental crust
V.E. = 3x
40
0 50 100 150 200 250 300 350 400 km
Figure 7.32 (a) Seismic velocity structure along the southern Lofoten–Vesterålen margin. COB, continent–ocean
boundary. (b,c) Gravity modeled transect and interpretation of the geology (images provided by F. Tsikalas and
modifi ed from Tsikalas et al., 2005, with permission from Elsevier). Densities in (c) are shown in kilograms per cubic
meter. SDR, seaward dipping reflectors. For location of profile see Fig. 7.31.