Reflectance spectroscopy in combination with cluster analysis as tools for identifying the provenance of Neolithic flint artefacts

Abstract

The provenance of flint artefacts found in archaeological excavations is very important for archaeologists to better understand artefact displacement, exchange networks, mobility patterns, prehistoric migrations and various cultural processes such as commerce, procurement strategies, territorial boundaries, etc. Reflectance Spectroscopy is an analytical technique that measures the radiation reflected by any type of surface, as it is sensitive to electronic and vibrational processes, both at the atomic and molecular level, which results in spectral signatures and absorption bands of the material. In this study the flint material of 16 quarries with evident signs of having been used to manufacture artefacts during the Neolithic period have been characterized by means of their spectral signatures and used to identify the origin of 5 flint blades found in a dolmen close to one of the quarries. The application of cluster analysis to compare the spectral signatures of both the quarries and the archaeological blades has ruled out one of them as not being sourced from the studied quarries, as well as assigning a very probable origin to the other four. Interestingly, none of the blades studied have been sourced to the nearest quarry, as one might presume. The results of this study confirm that reflectance spectroscopy combined with the multivariate statistical analysis could provide a powerful tool for determining the origin of flint artefacts which have been deposited in museums and other institutions.