SIGNIFICANCE OF SANDSTONE INCLUSIONS IN LAVAS OF COMORES ARCHIPELAGO

Inclusions of sedimentary rocks in basaltic lavas of the Comores Archipelago, western Indian Ocean, provide unequivocal evidence that this part of the Indian Ocean is underlain by non-oceanic crust. This supports the hypothesis of Dixey (1956) that the Mozambique Channel is geosynclinal in nature, implying that Madagascar was in its present position relative to Africa since late Carboniferous time, and probably since the Precambrian. In this light, the tectonics of the western Indian Ocean have not yet been satisfactorily explained by the hypothesis of sea floor spreading. © 1969.