Petrology of Some Volcanic Rocks from the Northern Fiji Plateau
Andesite from the island of Tikopea, approximately 200 km northeast of the New Hebrides, is similar to andesite from that island chain but richer in silica and alkalis. Samples collected from Anuda Island (about 320 km northeast of the New Hebrides Islands) and dredged from the Vitiaz Trench (150 km northeast of Anuda) are tholeiitic basalt. The formation of Tikopea Island is probably related to crustal fracturing on the Fiji Plateau, whereas that of Anuda Island may be tectonically related to the Vitiaz Trench.