SummaryThe ophiolitic complexes within the Indoburman orogenic belt form a conspicuous N-S line along the eastern margins of Manipur and Nagaland. The rock assemblages consisting of mafic-ultramafics are associated with deep sea pelagic sediments of the Disang Group (Lower Cretaceous-Eocene). The ultramafics in part, represent the oceanic crust and upper mantle material that formed the basement on which the radiolarites and other pelagic sediments were deposited. The fossil radiolaria present in the cherts suggest that the orogen took its foundation during late Jurassic-Lower Cretaceous time. The westward obduction of the flysch ophiolites in the form of large thrust sheets was possible during underthrusting of the Indian plate beneath the Burmese. The position of the ophiolitic belt defines the Indoburman suture zone.
Velocity Bounds on the Seismic Structure of Mesozoic Crust and Upper Mantle in the Southwest Pacific Basin from Downhole Observations at Deep Sea Drilling Project Hole 595B