Misleading residues on lithics from Star Carr: Identification with Raman microspectroscopy. (June 2018)

• Record Type: Journal Article
• Authors: Croft, Shannon; Chatzipanagis, Konstantinos; Kröger, Roland; Milner, Nicky
• Is Part Of: Journal of archaeological science. Volume 19(2018)
• Page Start: 430
• Page End: 438
• Publication Date: 2018-06
• Subjects: Non-anthropogenic residues -- Iron oxide -- Gypsum -- Quartz -- Reflected visible light microscopy (VLM) -- Confocal Raman microspectroscopy (micro-Raman); Archaeology -- Periodicals; Archaeology -- Research -- Periodicals; 930.1
• DOI: 10.1016/j.jasrep.2018.03.018
• Languages: English
• ISSNs: 2352-409X

Abstract

Abstract: Ancient trace residues left on stone artefacts by people represent a source of potentially fruitful data about diet, technology, and behaviour, but their investigation is not problem-free. Rather, correct identification of degraded residues and determination of their natural or anthropogenic origin remains at the heart of current methodological development in lithic residue analysis. It is increasingly becoming clear that reflected visible light microscopy (VLM) is insufficient to make secure identifications of ambiguous residues. Confocal Raman microspectroscopy (micro-Raman) is a non-destructive technique that can identify the specific molecular nature of microscopic residues with high spatial resolution. Here, the identification of artefact residues as anthropogenic by visual inspection alone was found to be incorrect in all cases tested. Micro-Raman provided the key source of information to unambiguously determine the chemical nature of residues and hence their origin. Highlights: Lithic residue identification by microscopy alone is often misleading. Raman microspectroscopy provides a means to test visual analysis. Red-orange deposits that appeared like resin were actually alpha iron (III) oxide. Crystal formations that appeared as phytoliths were actually gypsum. Fibrous formations that appeared as wood remains were actually gypsum.