The Antarctic Plate is almost completely surrounded by divergent margins and meets the south American and African Plates in the South Atlantic at the Bouvet Triple Junction (BTJ) located at 54 50'S, 00 40'W according to [Johnson et al.(1973),Forsith (1975)], [Sclater et al.(1976),Apotria and Gray (1985)] studied the evolution in space and time of the BTJ for last 20m.y., suggesting a Ridge-Transform-Transform(RFF) occasionally shifted to a Ridge-Ridge-Ridge configuration. The three ridge system that bound the plates and converge in the BTJ (MAR, AAR and SWIR)are among the slowest ridges on the planet (1.6, 0.9 and 0.83 cm/yr, respectively, [Sclater et al.(1976)]). The volcanic island of Bouvet, emerging 780 m from the sea level, located 140nM E of the BTJ, has been considered to be espression of a mantle plume [Morgan (1972)], capable of influencing topography and geochemistry of westernmost SWIR and easternmost AAR [LeRoex (1987)]. The southernmost MAR portion may also have influenced by the (hypothetical) Shona and Discovery plumes [LeRoex (1987),Douglass et al.(1995),Small (1995)].