**5.4 The continental nature of the subducting slab**

The nature of the New Caledonian Basin itself may also play a significant role in reducing arc volcanism because the New Caledonian Basin is a continental crust that is commonly dominated by dry granitic material [126, 127]. Furthermore, unlike the oceanic lithosphere, the lithospheric mantle underlying continental crust does not contain voluminous hydrous mineral phases [7, 29]. Therefore, the sinking slab of the New Caledonian Basin beneath the Norfolk Ridge did not provide the hydrous fluids necessary to lower the solidus of the mantle wedge and produce the arc volcanism associated with the Oligocene subduction zone [20].
