Glass circulation in late Iron Age Southeast Asia: New Compositional and Isotopic Data of Beads found at Non Ban Jak in Northeast Thailand

With this study we expand the glass data available for northeast Thailand through the analysis of elemental and isotopic (Sr-Nd-Pb) compositions of glass beads from Non Ban Jak. This site, located in Nakhon Ratchasima Province, Northeast Thailand, yielded more than 3000 glass artifacts dating from the mid-late Iron Age (CE 200-850). A representative selection of sixty-five glass beads was analyzed for elemental compositions, and Sr-Nd-Pb isotopic data were obtained for 10 of these beads. Most of the beads belong to the mineral soda – high alumina (m-Na-Al) 1 glass group, which originated from either Sri Lanka or southern India. Three color-specific sub-groups were identified: m-Na-Al 1.1, m-Na-Al 1.2 and m-Na-Al 1.3. Two glass samples with an orange color have a mixed-alkali composition also associated with India. Two glass beads have a potash composition usually associated with the Early Iron Age period and the South China Sea exchange network. Translucent dark blue beads have a soda-lime composition suggesting import from the west (the Mediterranean area or the Middle East). Results for Non Ban Jak show strong similarities with results from the neighboring sites of Ban Non Wat and Noen-U Loke and seem to share a strong connection during the Late Iron Age with South India/Sri Lanka.