Unravelling ceramic content and organic coatings in Senegalese ethnographic pottery vessels

Abstract

Ethnoarchaeological studies have highlighted a wide variety of organic coatings used by contemporary potters’ communities. Previous analyses have demonstrated the absorption of organic molecules from coatings in pottery, but these were mainly based on experimental approaches using only a few products, without considering the complexity of the chaînes opératoires of pottery manufacture. This study addresses the question of the identification of organic coatings, by investigating ethnographic vessels from three different pottery traditions in southern Senegal which involve such surface treatments. Coated pots are analysed before and after use, combining macro- and mesoscopic observations alongside biomolecular investigations. Based on observational criteria, this work highlights the partial degradation of the organic coatings during the initial use of the pottery, with an almost complete disappearance of visual clues observed after some months of use. Biomolecular analyses confirm that lipids from coating products can be absorbed. Yet, once the container has been used, it becomes challenging to distinguish between the coating products and the contents. However, one pottery displays molecular compounds that may originated from the coating product. These findings underscore the need to consider the entire life cycle of a ceramic vessel to ascertain the origin of the organic compounds trapped in its matrix. This origin may be traced back to either to the manufacturing stages of the vessel or to its use.