Origin of the New Caledonian ophiolites based on a French-Australian seismic transect

The origin, age and nature of the New Caledonian ophiolites are still debat ed. Recently, as part of the joint French-Australian Seismic Transect (FAUS T) program, the Australian research vessel Rig-Seismic recorded a series of multichannel deep-seismic profiles between the New Hebrides Are and the Au stralian margin. These profiles, which ran south of New Caledonia, image th e southern prolongation of the overthrusted ophiolites and allow a new inte rpretation of the Eocene compressive tectonism along the New Caledonia-Norf olk Ridge. A model involving abduction of the whole oceanic lithosphere of the Loyalty Basin is consistent with the age and origin of the ophiolite. V ariations in tectonic style along strike in the north-south-trending part o f the Norfolk Ridge have produced ophiolite exposures related to uplifted a nd partially overthrust upper mantle slivers within the southern part of th e Loyalty Basin. (C) 2000 Elsevier Science B.V. All rights reserved.