Statistical Analysis of Geochemical Data in the Shadan Mineral District Using a Compositional Data Approach

This study aims to evaluate the mineralization potential of the Shadan area based on the geochemical analysis of ۳۰۰ rock samples. Due to the compositional nature of geochemical data, the Centered Log-Ratio (CLR) transformation was applied to address the closure problem and enable meaningful statistical interpretation. Subsequently, fractal modeling using the concentration–area (C–A) relationship was employed to delineate geochemical anomalies where elemental concentrations increase significantly. In these anomalous zones, copper (Cu) concentrations reached up to ۰.۴۷ wt%, gold (Au) up to ۲.۵ g/t, and molybdenum (Mo) up to ۵۶ ppm. To better understand the underlying geochemical structure, robust factor analysis was conducted. This method minimizes the influence of outliers and provides more reliable factor patterns in complex geological settings. The analysis identified a dominant factor with strong negative loadings for Cu, Au, and Mo, indicating a clear geochemical association and a possible shared origin through mineralization processes. Spatial interpretation revealed that these anomalies are closely associated with intrusive bodies of quartz diorite to granodiorite, lithological units commonly linked to porphyry-type systems. Additional element associations were observed between Ni–Cr and Pb–Zn, suggesting the influence of deep mafic–ultramafic magmatic sources and zoned hydrothermal systems, respectively. These findings confirm the significant role of magmatic and hydrothermal processes in the enrichment of ore elements in the Shadan region. Overall, the results indicate that the Shadan area hosts a well-developed porphyry system and represents a promising target for further mineral exploration, particularly for Cu, Au, and Mo.

Keywords:

Shadan , compositional , statistics , robust factor analysis , geochemical rock samples