ABSTRACT
Plate tectonic theory has described the fitting together of various continents to varying degrees of accuracy. These fits have been based primarily on matching of coastlines, bathymetry, certain geophysical signatures, and continent to continent geological/geophysical trends at conjugate continental margins. This chapter describes the evolution of the Somali Basin and the East African continental margin from about 16° S to 5° N. It explores the kinds of evidence to be in describing this evolution are marine magnetic lineations in the Somali Basin, onshore geologies of Malagasy and East Africa, gravity anomalies over the entire region. The chapter also explores Deep-Sea Drilling Program (DSDP) site results, satellite altimeter data, and seismic reflection/refraction data from the basin. Passive margins develop when continents rift apart to form new oceans, so that the continent and adjacent sea floor are part of the same plate.
