Porolissum Romania. Preliminary investigation methods for identifying raw material source of lime using statistical data analysis of PIXE results

Restoration of a Roman customs building in Porolissum–Moigrad, Romania, provided an opportunity to identify matching criteria between raw limestone materials from neighbouring quarries and the mortar recovered from the building’s foundations, using Particle-Induced X‑Ray Emission (PIXE) and Principal Component Analysis (PCA). A strategy based on known quarries from the Roman period and the distances relevant to construction logistics was applied, leading to the selection of the Moigrad (limestone), Creaca (compact limestone), and Buciumi (shelly limestone) quarries. Lime lumps extracted from the mortar served as key indicators for establishing the provenance of raw materials. PCA results showed that Moigrad and Buciumi were the main and closest sources of limestone, whereas Creaca was most likely not used for producing quicklime.