The 2007 excavation of Kasasinabwana Shell Midden opened a new chapter on Lapita on the south coast of Papua New Guinea. We look to establish the degree to which the Kasasinabwana assemblage fits into the current understanding of Lapita colonisation by investigating modes of pottery production utilising physico-chemical analysis of the ceramics and patterns of obsidian exploitation using portable X-ray fluorescence (pXRF). Three separate ceramic Chemical Paste Compositional Reference Units (CPCRUs) are identified along with the presence of calcareous non-plastic inclusions in layers associated with possible colonisation phases. Obsidian is present from around 2000 b.p. and its appearance seems to correspond with the emergence of Early Papuan Pottery (EPP). The Lapita ceramic production model fits well with Late Lapita production.