Evidence indicates that the impact
angle was about 30 degrees above the horizon,
1. Artemieva, N. 2008. Tektites: Model Versus Reality.
39th Lunar and Planetary Science Conference, p. 1651.
Putting the scattered pieces of Earth's crust back together reveals the hole where the giant meteorite vaporized and excavated the continental crust, including the side blowouts.
The remnants of the crater walls can still be seen as rounded cuts on the coasts of East Africa, northern Madagascar, and southern Australia
impact was onto continental crust. But as the land separated,
the ocean rushed in and obliterated the crater rim. This is
typical for craters in the ocean.
Yet some effects are evident on the west side. The coasts of Kenya and Tanzania show severe faulting and diapirism (cracks into which magma seeped). Numerous normal (pull-apart) faults are downthrown to the east. The continental shelf is quite narrow (25 to 50 km), with a steep continental slope.1 Such partial collapse is typical of impacts on the continental margin.2
1. Coffin, M.F., P.D. Rabinowitz. 1988. Evolution of the conjugate East-African-Madagascan margins and the Western Somali Basin. Geological Society of America Special Paper 226.
2. Dypvik, Henning, Lubomir F. Jansa. 2003. Sedimentary signatures and processes during marine bolide impacts: a review. Sedimentary Geology, Vol. 161, pp. 309-337.
The West Somali Basin basalt floor has scarcely been sampled. Drilling was attempted at two sites (240 and 241) in 1972 as part of the Deep Sea Drilling Project. The drill bit broke after penetrating just 1.2 meters into basalt at site 240, and never reached basalt at site 241. No one ever tried again.