Contribution of hyperspectral analysis in relative dating applied to Miculla petroglyphs (Peru)

The Tacna region in southern Peru hosts archaeological remnants of Pre-Columbian period human occupations, including the Miculla Petroglyphs. Existing methods for dating these petroglyphs present substantial uncertainties and are subject to claims lacking objective validation. This study employs advanced hyperspectral analysis, specifically utilizing the SPECIM IQ camera, to reevaluate existing chronological proposals for these petroglyphs. The employed analytical technique is non-destructive and captures spectral data across an extensive range of wavelengths. This allows for a quantitative assessment of patination levels attributable to solar exposure, in comparison to adjacent intact areas. Data from various petroglyphs were analyzed using SPECIM IQ Studio software and Matlab. The analysis differentiated between "engraved" and "varnished" regions on selected boulders. Reflectance ratios between these areas were compared to provide insights into the potential relative ages of different sets of engravings. The results question pre-existing chronologies based on cultural classification schemes for the petroglyphs. While the study underscores the utility of hyperspectral analysis in refining petroglyph dating, it also indicates that this method cannot replace a multi-method approach without further resolution refinement.