Chemometrics applied to cathodoluminescence images: a new approach to classify pre-Columbian artefacts from northern Peru.

In most archaeological researches, ceramic cathodoluminescence images are conventionally exploited in a descriptive way (paste colour, inclusions). In this study, a new approach was employed: image's RGB histograms were used in order to differentiate several ceramics recently discovered at the archaeological site of San José de Moro located in northern Peru. Cathodoluminescence coupled with chemometric methods appears as a good method to characterize and particularly to produce a systematic classification of complex materials such as archaeological ceramics. Our results were compared with the archaeological and classical background knowledge and this allowed confirming that Mochica Fine Line and Mochica Polychrome were the most similar archaeological groups, at Mochica times, because of the use of the same raw material for production. However, Highland Cajamarca is the most different ceramic group from the other studied ones due to the use of different raw materials from Cajamarca valley located 100 km east of San José de Moro site.