Synthesis of morphotectonics and volcanics of the Central Indian Ocean Basin

Abstract

The Central Indian Ocean Basin (CIOB) is an enigmatic ocean basin in the young and tectonically complex Indian Ocean. Major tectonic and volcanic forms identified are fracture zones, abyssal hills, seamounts and ridges and a unique zone of intraplate deformation. Petrology indicates the presence of basalts, ferrobasalts and spilites. The basalts have erupted from moderately evolved magmas, the ferrobasalts from a long residing and shallow seated magma body while the spilites have formed due to the hydrothermal effect on the pre-existing subalkaline basalts. Besides these rocks, there is a wide occurrence of pumice of probably in situ origin. A distinct relation occurs between the morpho-tectonic forms and the volcanics. For example, in and around the topographic highs, pillow and massive basalts are common while close to fracture zones, flow lavas occur. Two significant volcanic activities: one during the formation of the near-axis generated seamounts and the other in an intraplate environment are perceived