Brit Asmussen

New direction in human colonisation of the Pacific: Lapita settlement of south coast New Guinea

Abstract Expansion of Austronesianspeaking peoples from the Bismarck Archipelago out into the Pacific commencing c.3300 cal BP represents the last great chapter of human global colonisation. Bismarck Indonesia Archipelago Papua New Guinea Torres Strait Caution Bay The earliest migrants were bearers of finelymade dentate-stamped Lapita pottery, hitherto found only across Island Melanesia and western Polynesia. We document the first known occurrence of Lapita peoples on the New Guinea mainland. The new Lapita sites date from 2900 to 2500 cal BP and represent a newly-discovered migratory arm of Lapita expansions that moved westwards along the southern New Guinea coast towards Australia. These marine specialists ate shellfish, fish and marine turtles along the Papua New Guinea mainland coast, reflecting subsistence continuities with local pre-Lapita peoples dating back to 4200 cal BP. Lapita artefacts include characteristic ceramics, shell armbands, stone adzes and obsidian tools. Our Lapita discoveries support hypotheses for the migration of pottery-bearing Melanesian marine specialists into Torres Strait of northeast Australia c.2500 cal BP.

High-resolution radiocarbon dating of marine materials in archaeological contexts: radiocarbon marine reservoir variability between Anadara, Gafrarium, Batissa, Polymesoda spp. and Echinoidea at Caution Bay, Southern Coastal Papua New Guinea

The remains of shellfish dominate many coastal archaeological sites in the Pacific and provide a wealth of information about economy, culture, environment and climate. Shells are therefore the logical sample type to develop local and regional radiocarbon chronologies. The calibration of radiocarbon (14C) dates on marine animals is not straightforward, however, requiring an understanding of habitat and dietary preferences as well as detailed knowledge of local ocean conditions. The most complex situations occur where terrestrial influences impinge on the marine environment resulting in both the enrichment and depletion of 14C (Ulm Geoarchaeology 17(4):319–348, 2002; Petchey and Clark Quat Geochronol 6:539–549, 2011). A sampling protocol that combines a high-resolution excavation methodology, selection of short-lived samples identified to species level, and a tri-isotope approach using 14C, δ13C and δ18O, has given us the ability to identify 14C source variation that would otherwise have been obscured. Here, we present new research that details high-resolution mapping of marine 14C reservoir variation between Gafrarium tumidum, Gafrarium pectinatum, Anadara granosa, Anadara antiquata, Batissa violacea, Polymesoda erosa and Echinoidea from the Bogi 1 archaeological site, Caution Bay, southern coastal Papua New Guinea. These isotopes highlight specific dietary, habitat and behavioural variations that are key to obtaining chronological information from shell radiocarbon determinations.