Extraction of Regional and Local Anomalies of Element Group in the Ailaoshan Tectonic Zone, Southwestern China

Geochemical data provide direct constraints on mineralization, and the extraction of mineralization-related geochemical anomalies is essential for mineral resource prediction and assessment. The regional geochemical field reflects the spatial expression of ore-forming environments resulting from the superposition of multiple geological processes, with distinct elemental assemblages corresponding to different processes. The Ailaoshan metallogenic belt, located in the southeastern segment of the India–Eurasia collisional orogen, experienced multiple episodes of opening and closure, extension, amalgamation, and compression, leading to intense deformation. Its complex structural framework, multistage magmatism, and metamorphism have generated abundant mineral resources, particularly Au, Sn, Cu, Pb-Zn, and Ni deposits. Using the 1:200,000–scale national stream sediment geochemical dataset, principal component analysis (PCA) was applied to identify major ore-forming elemental assemblages. Singular value decomposition (SVD) was then used to extract regional and local anomalies for PC2 (Ag-As-Bi-Cu-Mn-Pb-Sn), PC3 (B-Be-Bi-Cu-F-W), PC4 (La-Nb-Th-U-Y-Zr), and PC10 (Au-Hg). Ultimately, six metallogenic prospective areas were consequently delineated.