Contrasting Volcanic Suites in Naga Hills and Their Bearing on the Tectonic Evolution of the Naga Hills Ophiolite Belt, N.E. India

Abstract

The 200 km long Naga Hills opiliolite belt which forms the northern part of the Indo-Burman ophiolites is made up of two contrasting volcanic suites. viz.; (1) high-Mg basalts (Mg-number 52 to 71) comparable to mid-oceanic ridge basalts and (2) low-Mg (Mg-number 23 to 49) akin to seamount type volcanism.

Based on geological and geochemica 1 evidences, a three stage model comprising (1) marginal basin spreading event, (2) seamount event and (3) collision event, is presented to explain the origin and evolution of the Naga Hills ophiolites.