Mobility of early islanders in the Philippines during the Terminal Pleistocene/Early Holocene boundary: pXRF-analysis of obsidian artefacts

The Philippine archipelago spans over two distinct biogeographic zones, Sundaland and Wallacea. We report in this paper on finds from Ilin Island just off the coast of SW-Mindoro, and El Nido in Northern Palawan. While the island of Palawan is linked to Sundaland, Mindoro and Ilin Island belong to Wallacea, east of Huxley's Line. Ongoing archaeological investigations at Bubog 1 Rockshelter on Ilin Island and Ille Cave & Rockshelter in northern Palawan, delivered obsidian artefacts, found in Terminal Pleistocene and Early Holocene layers. PXRF analysis of the obsidian samples from Mindoro and Palawan shows that they were coming from the same, yet unknown source. They clearly indicate that the two distinct paleogeographical regions were linked to each other, suggesting human interaction and maritime networks as early as ca. 12ka BP. The results of this study contribute substantially to our understanding of the mobility of early islanders during the Terminal Pleistocene and the processes of human island adaptation and enhance our current knowledge of subsistence strategies across the region.