Application of SVD combined with PCA in delineation and evaluation of ore-prospecting targets in the Gejiu tin polymetallic cluster region, SW China

Abstract

The Gejiu tin polymetallic cluster region, situated at the northeastern side of the Ailaoshan-Red River Fault and the junction area between the Cathaysia terrane and the Yangtze terrane, is associated with the late Cretaceous magmatic-hydrothermal metallogenetic event. In this study, a singular value decomposition (SVD) is effectively used to extract the anomaly components from the metallogenetic element groups established by the principal component analysis (PCA) for the identification of the ore-prospecting targets. Three steps are shown: (1) the metallogenetic element groups are obtained using PCA; (2) the element anomaly components formed by magma-hydrothermal metallogenetic events are extracted using SVD from the metallogenetic element groups; and (3) the local and regional element concentration anomaly components are identified by applying the element anomaly components corresponding to different eigenspaces. Finally, ten ore-prospecting targets for the Bi-Pb-Sn-Th-W-Cu mineralization, two ore-prospecting targets for the Ag-Cd-Hg-Zn-Mn mineralization, and two ore-prospecting targets for the La-Nb-Th-Zr-U-Y mineralization are delineated, respectively. The results certify that SVD can discriminate not only the regional element concentration anomaly components formed by the magmatism but also the local element concentration anomaly components triggered by the metallogenetic processes from the metallogenetic element groups established by the PCA.