EMF - Abstracts

The Characterisation and Radiocarbon Dating of Archaeological Resins on Ceramics from Southeast Asia: What might they tell us?

C.D. Lampert, I.C. Glover, C.P. Heron, B. Stern, R. Shoocongdej and G.B. Thompson
(Bradford University)

Keywords: resin, terpenoids, GC-MS, ceramics, radiocarbon dating, Southeast Asia.

Deposits of resin on potsherds from a number of archaeological sites in mainland Southeast Asia provides evidence for the exploitation of plant resins during prehistory. Whilst resins are a widespread natural resource throughout Southeast Asia, it is unclear which of the many resinous species were exploited in the past. To this end, a study is underway, which aims to characterise resins from sites of different type and age and to investigate their potential for dating purposes. The aims can be subdivided into four key objectives: to identify the resins to a botanical source, to explore how and why they were used, to compare the use of resins across geographical distance and time, and to evaluate the merit of resins for radiocarbon dating. Archaeological material from a number of prehistoric sites, in coastal, lowland and upland areas, is included in this study. The chemistry of resins is complex but they are principally mixtures of terpenoids. Well-established methods to investigate solvent-soluble components of modern resins include gas chromatography and gas chromatography-mass spectrometry, sometimes combined with pyrolytic techniques to explore the high MW or polymeric insoluble fraction. This approach is equally applicable to archaeological resins. Thus far, a number of archaeological samples have been examined using GC and GC-MS and preliminary results indicate that resins from the Dipterocarpaceae family were used as coatings or adhesives on some Southeast Asian pots. Ethnographic evidence suggests resin coatings are applied to pots soon after firing and resins used as adhesives are applied within the functional lifetime of the pot. Consequently, the resins can be seen as contemporaneous with the vessels and may provide a method of dating the ceramics directly. In applying radiocarbon dating to archaeological resins it is hoped to establish them as a reliable source of material to provide further information regarding the chronology of both individual artefacts and sites. Results obtained from the first batch of material submitted for dating is promising, suggesting that resins can provide reliable and repeatable radiocarbon dates.