Figure 7. Enlargement of the velocity model of profile LG12 next to Site 901 derived from iterative prestack depth migration. Sediment velocities increase (Vp = 1.7-4.1 km/s) from shallow to deeper levels, and those sampled on top of the tilted block (Vp basement = 5.5 km/s) are most likely of prerift age (Shipboard Scientific Party, 1994c). In contrast, the prerift sequence near Site 900 shows higher velocity values than the layer here, which is characterized by mud-dominated ooze and clay as proved by sampling.