THE POYA-NAPPE, EX-FORMATION-DES-BASALTES (NEW-CALEDONIA, SOUTHWEST PACIFIC) - A CAMPANIAN TO UPPER PALEOCENE OCEANIC PLATEAU OBDUCTED IN THE LATE EOCENE

Submarine mafic volcanic rocks, dolerites, gabbros and associated abys sal sediments comprise a comprehensive tectonostratigraphic unit (the Poya Terrane) that tectonically overlies all pre-Neogene rocks in New Caledonia except the ultramafic allochthon. These magmatic rocks forme d between the Campanian and the Late Palaeocene or earliest Eocene as inferred from radiolarian data, metamorphosed to the greenschist facie s and later to the blueschist facies, and tectonically emplaced in the late Eocene. The mafic volcanic rocks comprised predominant P-MORB, r are BABE, OIB and boninites, that represent an oceanic plateau origina lly belonging to a marginal basin located to the NE of New Caledonia.