Reconstructing the Chronology and Environmental Context of Hoabinhian Shell Middens on Bintan Island, Indonesia

Gilbert J. Price1*, Holly E. Reid1, Yahdi Zaim2, Agus T. Hascaryo2, Mika R. Puspaningrum2, Yan Rizal2, Aswan2, Kira Westaway3, Benjamin P. Shidqi1,4, and Julien Louys4

The Hoabinhian technocomplex represents a widespread Late Pleistocene to Holocene hunter-gatherer tradition across Southeast Asia, yet the chronology and environmental context of many sites remain poorly resolved. Shell middens associated with Hoabinhian lithics on Bintan Island, Indonesia, provide an opportunity to address these gaps. Kawal Darat Shell Midden I is a substantial deposit (~4 m thick, ~18 m across) dominated by dense accumulations of marine mollusc shells and associated artefacts, including characteristic pebble tools (sumatraliths), indicating a clear cultural association with the Hoabinhian technocomplex. Previous dating has produced very late Holocene ages but lacks stratigraphic control and appropriate correction for marine reservoir effects, limiting interpretive value. To establish a robust chronological framework for midden formation and human occupation, stratigraphically controlled shell samples were collected from an exposed excavation trench at 25 cm intervals. Fourteen mollusc samples are currently being analysed using accelerator mass spectrometry radiocarbon dating. Additional constraints will be provided by luminescence dating of sediments and U-series dating of associated coral rubble. Complementary analyses include taxonomic identification of mollusc assemblages and stable isotope measurements to reconstruct paleoenvironmental conditions during midden accumulation. Shells from the nearby Kawal Darat Shell Midden III, which contains a contrasting assemblage including mangrove-associated taxa and freshwater bivalves, are also being dated to evaluate differences in environmental setting and site use. This work will provide the first stratigraphically constrained chronological framework for Hoabinhian shell middens on Bintan Island and inform broader discussions of hunter-gatherer subsistence, coastal resource use, and environmental change in Island Southeast Asia during the Late Quaternary.