Raw material variability and trace formation

he global archaeological record is characterised by diverse stone tool raw materials that were exploited by prehistoric knappers according to local geology, mobility systems, and exchange networks. Yet most methodological development in use-wear analysis has taken place in Europe and has been focused on flint and similar cryptocrystalline lithic raw materials. This has created a significant imbalance in the geographical range of detailed use-wear data currently available to us and produced a situation where e.g., African stone tool industries are poorly understood from a functional perspective compared to their European counterparts.

TraceoLab has a focus on developing and applying methods for the analysis of non-flint rocks building on the efforts of earlier researchers. Our current work involves sites with industries in basalt, different cherts, dolerite, hornfels, obsidian, quartz, quartzite, radiolarite and sandstone. We are interested in the differential wearing down of rocks under mechanical stress and the implications it may have had for human choice of tool materials in the distant past.

To understand these processes, we use both controlled machine experiments and actualistic experiments that replicate past human toolmaking and tool use. We have also conducted blind tests to understand how previous training and lack of suitable reference material can bias use-wear identifications when the analyst encounters a new raw material.

This methodological basis allows us to apply modern use-wear analysis in different geological contexts. We have for instance tried to improve methods for identifying projectiles in African archaeological assemblages and we have produced reference sets for identifying hafted tools in different raw materials. This work ties to our research into Early and Middle Stone Age industries in Africa and Middle and Upper Palaeolithic technology in Europe. In each archaeological case study, we aim to match the raw material of the experimental tools to their archaeological counterparts as closely as possible, and the present reference collection consequently includes stone tools made in raw materials deriving from various geological contexts in Western Europe and parts of Africa and Australia.

Raw material variability and trace formation

Further reading