Differentiating Quilombola Ceramic Provenance Through EDXRF, GRS and Principal Component Analysis

This study applies archaeometric techniques—gamma-ray spectrometry (GRS) and energy-dispersive X-ray fluorescence (EDXRF)—to investigate the ceramics from three Quilombola communities in Maranhão, Brazil. Ceramic and clay samples from these communities were analyzed using principal component analysis (PCA) of full-spectrum GRS and EDXRF data, supplemented by elemental scatter plots. The aim was to evaluate the effectiveness of the methodology in distinguishing samples of different origins. PCA of the EDXRF and GRS datasets clearly identified three distinct sample groups, aligning with initial expectations. Scatter plots of elemental concentrations, mainly Ca vs. Al, S, Fe, K, V, and Si, showed a separation for one group with higher Ca content. While Th/U ratios showed the same partial separation, distinguishing one group from the others, K/Th ratios did not. These results show the effectiveness of the GRS and EDXRF approach for ceramic provenance studies in similar archaeological contexts.