Petrology of seamounts in the Central Indian Ocean Basin: Evidence for near-axis origin

Abstract

Previous studies on the distribution and morphology of ancient seamount chains (>50 Ma) in the Central Indian Ocean basin (CIOB) indicated their generation from the fast spreading Southeast Indian Ridge. The petrology of some of these seamounts is described. Fresh glass veneers of pillow basalts from these seamounts were analyzed by electron microprobe. The rocks show a low cotent of TiO sub(2) and FeO and moderate Mg suggesting slow eruption of a minimally frationed N-MORB magma. In terms of chemistry and morphology. CIOB seamounts are indistinguishable from seamounts across slow spreading MAR and fast spreading EPR.