Obsidian Sourcing at Ulilang Bundok Site and its Implications for Mobility, Exchange, and Social Contexts in the Philippine Metal Age

This article discusses the results of chemical analysis to trace the source of the obsidian artifacts from the site of Ulilang Bundok in Batangas, Philippines. The obsidian artifacts used in this study were excavated from the site of Ulilang Bundok while samples of obsidian were also collected from known obsidian sources in Nagcarlan, Batangas, and Pagudpod, Ilocos Norte, for comparative purposes. Chemical analyses of the obsidian artifacts and source samples were carried out on a scanning electron microscope using the energy dispersive X-ray spectrometer at the University of Science Malaysia, Penang and the electron microprobe at the University of Malaya, Kuala Lumpur. Multi-elemental analysis and statistical procedures performed on elemental data obtained from the obsidian artifacts and sources provided strong indications that the obsidian artifacts from Ulilang Bundok were made using obsidian obtained from the Nagcarlan source. The chemical sourcing results are significant in that they suggest that obsidian was a limited and valued raw material that was likely mined and traded through expanding social exchange networks. This has further implications for understanding how the complexity and spatial extent of trade reflects emerging social complexity in the Philippines Metal Age.