This study presents a high-resolution elemental characterization of a 4th-century Roman bronze coin using micro-PIXE analysis equipped with a four-segment annular Silicon Drift Detector (SDD) array. The multi-detector configuration enhances angular coverage and count statistics, allowing for spatially resolved mapping of both alloy constituents and surface contaminants. Elemental quantification was performed using GUPIX, accounting for both bulk and surface contributions. Complementary X-ray fluorescence (XRF) analysis was conducted to probe deeper into the coin's matrix and validate the core alloy composition. Micro-PIXE revealed Cu, Pb, and Sn as the dominant alloy elements, while surface-associated elements such as Al, Si, P, and Ca were attributed to environmental contamination and corrosion products. Scatter matrix plots were employed to assess correlations among elemental concentrations across different coin regions. Strong correlations among Cu–Sn and Sn–Pb confirmed typical bronze alloying patterns, while surface elements showed associations consistent with burial-related alterations. This work demonstrates a methodological advancement in combining angularly resolved multi-detector PIXE with XRF for robust stratigraphic analysis of corroded cultural heritage metals.
