The function of the south-Levantine Late Chalcolithic and Early Bronze Age basalt vessels bearing circumferential depressions: Insights from use-wear analyses.

One of the most characteristic aspects of the Late Chalcolithic and Early Bronze Age periods in the southern Levant is the appearance of large assemblages of basalt vessels. These vessels, frequently meticulously made, appear sometimes a considerable distance from the raw material sources and are found mainly at habitation sites. While these and their prestigious value have been widely discussed in the past, their function is still obscure. In the current paper, we address their functionality through microscopic use-wear analysis. Emphasis was placed on basalt vessels with a distinct wear pattern-circumferential depressions, which appear along the perimeter of their interior bases. The documented traces were compared to results of an experimental study we conducted to characterize the effects of abrasion, grinding, and lubrication on basalt surfaces. The results of the comparative experimental study suggest that the circumferential depression was formed from a repetitive rotational activity using a narrow-ended tool. Further, it seems that two material types acted in combination as the circling device and processed material. One was hard and abrasive, such as stone, and the other was semi-resilient, such as wood or mineral powder. Water was likely used as a lubricant in the rotational process. While the actual function of the bowls bearing the circumferential depressions is not entirely clear, the use-wear analyses suggest that they may have been devices involved in craft industries, used for processing materials unrelated to food (minerals in particular). Whatever the exact function was, it clear that this use continued from the Chalcolithic through the Early Bronze Age, providing evidence for functional continuity between these two periods.