COMPARISON OF CHERT GEOCHEMISTRY AND FLINT KNAPPING WORKABILITY

Possible relationships between the geochemistry of various chert samples and their workability into stone tools were investigated. A number of chert types utilized by ancient peoples in the manufacturing of stone tools were identified, including Alibates (TX), Arkansas Novaculite (AR), Caballos Novaculite (TX), and Burlington chert (MO). Samples of the chert were knapped and graded on a workability index. The index is based on key aspects of flint knapping which determine the difficulty in effectively obtaining a stone point. Geochemistry of these chert, obtained from published literature, was examined. The chert geochemical characterizations were compared to the workability index grades for investigating correlations between the two. For example, the research included a study of chert samples with higher traces of iron to find any possible knapping characteristics exclusive to that characteristic. Although study continues, “number of inclusions/sample purity” and “internal fractures” appear to play a greater role in workability than minor geochemical disparities. Also the quartz matrix size in chert could contribute to fracturing during the manufacturing process due to the gradual loss of flake momentum, and thereby reduce workability. Further research is currently being conducted to test this reasoning. The selective use of a specific chert type by ancient stone workers may have been more driven by availability than by slight differences in workability resulting from geochemical variation.