Field spectroscopy in geoarchaeology – A comparative investigation of quartz and quartzite quarries and stone implements

Spectroscopy provides a new proxy for reconstructing prehistoric raw-material procurement, mobility, and inter-settlement interaction, through linking archaeological stone tools to specific quarry sources. In this paper, spectral responses have been analyzed using chemometric methods, particularly principal component analysis (PCA) and t-distribution stochastic neighbour embedding (t-SNE), to capture meaningful differences between quartz and quartzite raw materials and to analyse possible relationships between archaeological stone tool assemblages and quarries. Field adapted near infrared reflectance (NIR) spectroscopy and X-ray fluorescence (XRF) instruments have been used to analyse prehistoric quartz and quartzite quarries in inland Västerbotten (Sweden), and the collected spectral data were compared with tool assemblages from curated archaeological collections. Despite challenges inherent to field sampling, the combined spectroscopic approach reliably differentiates raw material groups, demonstrating its suitability for archaeological prospection and excavation. These findings underscore the value of integrating spectroscopy into routine fieldwork, providing a modern analytical toolkit that expands the interpretive potential of archaeological fieldwork.