Glass Exchange and Changing Networks at Phromthin Tai, Central Thailand

This study examines glass beads from Unit S4 at Phromthin Tai (PTT), Lopburi, to investigate changing exchange networks during the transition from the early to later first millennium ce. LA-ICP-MS analysis shows that the assemblage is dominated by m-Na-Al 1 glass associated with southeastern India, while m-K glass, linked to South China Sea-oriented networks, occurs only in a few earlier contexts. Comparison with the previously published S3 assemblage reveals a marked shift from m-K glass toward South Asian m-Na-Al glass within the Mekong Interaction Sphere. The identification of v-Na-Ca glass further expands the compositional diversity of the PTT assemblage.