Chapter 12: Petrography of Coastal Sands and Prehistoric Sherd Tempers from the Northwestern Coast of Papua New Guinea

Abstract

Petrographic study of the temper sands in fifty prehistoric potsherds from the mainland coast and nearby offshore islands of northwestern Papua New Guinea, and comparison of the temper sands with modern coastal sands of the region have shown that temper grains were derived from largely volcanogenic bedrock of the Torricelli Mountains and associated ranges lying inland from the coast. Temper aggregates include both natural tempers embedded in clay bodies and manually added tempers of both fluvial and beach origin, but all the tempers are generically similar, being composed of varied arrays of mineral grains and rock fragments with broadly common origins. Seven temper groups are defined petrographically on the basis of sand texture and mineralogy, and most or all can be identified from megascopic examination of sherds without microscopic analysis. Temper analysis provides no evidence for importation of pottery into the region from elsewhere, nor do any potsherds studied to date from the Bismarck Archipelago contain tempers indicative of ceramic transfer eastward from northwestern Papua New Guinea.