The Fiji Islands are remnants of a once continuous Solomon-Vanuatu-Fiji-Tonga volcanic arc (the Vitiaz arc), located at the
boundary between the Indian-Australian and Pacific plates. They record a history of (i) arc volcanism the late Eocene to late
Miocene, (ii) an extensive magmatic response to arc rifting (5.5-3.OMa) during which volcanism was dominated by shoshonitic
to tholeiitic basalts, and as rifting continued, (iii) a transition from arc to intraplate volcanism. The Hunter Ridge-Hunter Fracture Zone separates the inactive South Fiji Basin from the actively spreading North Fiji
Basin, and has been considered to be a transform zone, almost parallel to the motion vector of the Australian plate. However
rocks dredged during the 1993 `Alize' cruise, from along the northern part of the Hunter Ridge are typical arc tholeiites, and
therefore demand that subduction has occurred beneath the Hunter Ridge sometime during the last - 5Ma.