Changing shorelines and cultural orientations in the Sepik‐Ramu, Papua New Guinea: Implications for Pacific prehistory

Abstract

Today the Sepik and Ramu rivers drain the north‐west mainland of Papua New Guinea. A joint archaeological and geomorphic research programme has revealed that their modern joint flood‐plains were once a brackish inland sea. During the period of the inland sea the north coast was much closer to the intermontane valleys of the Papua New Guinea highlands. Six to five thousand years ago, this former inland sea would have allowed an almost direct exchange of ideas and products between the people inhabiting its shoreline and the highlands. This was also a period of growing contact with Asia, as attested by the 5800 BP betel‐nut husk excavated from the Dongan marine midden and the pre‐Lapita pottery found in the north coast sites and in the highlands at Wanlek. Such finds challenge the assumption that Lepita pottery signals the entry of Austronesian speakers throughout Melanesia.