Part 5. Plate boundary evolution in the New Guinea region: Volcanic and plate tectonic evolution of central Papua New Guinea

Abstract

Volcanic activity in central Papua New Guinea began in the Upper Triassic with submarine and terrestrial eruption of andesitic and dacitic lavas on and adjacent to the north-east corner of the Palaeozoic Australian continental crust. Minor basaltic to rhyolitic eruptions took place during the Jurassic in the same general area. During the Cretaceous, volcanic activity increased in intensity and distribution, spreading to the north and west (Fig.1), and produced mainly andesitic lavas, both subaerial and submarine. The increase in activity in the Cretaceous, may correlate with the beginning of spreading in the Pacific basin to the northeast (Packham, 1973), and could therefore have been a result of the first subduction in the area. There is no evidence to link the earlier volcanism with subduction, although it took place on or near a plate boundary.