Quartzite complexities : Non-destructive analysis of bifacial points from Västerbotten, Sweden

• Published in: Journal of Archaeological Science: Reports
• Main Authors: Sjölander, Mattias, Linderholm, Johan, Geladi, Paul, Buckland, Philip I.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Umeå universitet, Miljöarkeologiska laboratoriet 2024
• Subjects: archaeology; spectroscopy; chemometrics; quartzite; bifacial point; Sweden; Arkeologi; Fennoscandia; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-219848; https://doi.org/10.1016/j.jasrep.2024.104381

Northern Fennoscandia is a geologically complex region affected by both glacial and postglacial processes. Quartzite was a key material type utilized by hunter-gatherers in Northern Sweden around the period 4 000 – 2 000 BP, and is thus critical to the understanding of raw material procurement and material flow within the region. However, there is a severe lack of methodological development in the characterization of these materials, and provenance of locally available geological material is complex and fraught with uncertainty. 126 quartz/quartzite points and preforms were sampled from 47 archaeological sites along the upper Ångerman river valley in Västerbotten, Sweden. The material has been analysed non-destructively using three separate portable spectroscopic instrumentations (Near-infrared, Raman, X-Ray Fluorescence). Evaluation of the spectra and exploratory data analysis using Principal Component Analysis demonstrates detectable differences in the material that likely stem from diagenetic/paragenetic origin. The presence of graphite, muscovite and biotite could likewise provide information on the material’s metamorphic grade. In addition to reaffirming the potential of field-based screening instrumentation, these results will benefit future surveys of geological sources in the region. They also indicate potential for the construction of a predictive model that could classify the quartzite based on its chemical characteristic. Such a model would prove useful in future spatial analysis and testing of models of raw material management.