Identification of ore-finding targets using the anomaly components of ore-forming element associations extracted by SVD and PCA in the Jiaodong gold cluster area, Eastern China

Abstract

Multi-stage geological processes (i.e. magma and hydrothermal processes) produce generally regional and local element concentration anomalies of ore-forming elements. The Principal Component Analysis (PCA) can be applied to establish various types of ore-forming element associations, which can be further divided into two different anomalous components with the help of the Singular Value Decomposition (SVD). One can be defined as a regional geochemical anomaly generated by geological processes (i.e. magmatism); and the other can be regarded as a local geochemical anomaly created by ore forming events. Three aspects are illustrated in this paper: (a) The ore-forming element associations are established by PCA; (b) The geochemical anomaly components created by both magmatism and hydrothermal ore-forming processes are respectively identified by the SVD from the ore-forming element associations; and (c) The regional and the local geochemical anomalies are delineated using the geochemical anomaly components corresponding to different eigenspaces. The PCA and SVD methods were applied gold polymetallic ore-prospecting target areas and molybdenum polymetallic ore-prospecting target areas in the Jiaodong gold cluster area, China by delineating their regional and local geochemical anomalies. The results show that the SVD can extract not only the regional anomalies associated with magmatism, but also the local anomalies related to the hydrothermal processes from multi-element associations produced by PCA.