Seismic refraction measurements in the northwest Indian Ocean

Fifteen seismic refraction profiles in the northwest Indian Ocean are described. The results suggest a connection between the linear Maldive ridge and the Deccan traps of the Indian mainland. No anomalous upper mantle velocities have been found near the crest of the Carlsberg ridge. A great thickness of material with velocity 6.03 km/sec west of the Saya de Malha bank has been interpreted as an extension of the Seychelles granitic block to the south. At two stations between the Chagos archipelago and the Seychelles bank the Mohorovicic discontinuity appears to be less than 8 km below sea level.