Identification of the Ore-Forming Anomaly Component by MSVD Combined with PCA from Element Concentrations in Fracture Zones of the Laochang Ore Field, Gejiu, SW China

Abstract

Fault and fractures are well-developed in the Gejiu tin-polymetallic district, and they are closely related to the formation and distribution of ores. In this paper, the principal component analysis (PCA) and multifractal singular value decomposition (MSVD) methodologies were applied for identification of the ore-forming anomaly components from element concentrations of fault rocks in the Laochang ore field, Gejiu. The results show that: (1) the wall rocks and fault rocks have anomalous concentrations of ore-forming elements, indicating that these elements are mainly derived from fluid/rock interaction in the fracture zones; (2) PCA based on clr-transformed data was used to recognize significant association anomalies of ore-forming elements, which lay a foundation for further extracting ore-forming anomaly components from the element association anomalies related to Sn-Cu mineralization; (3) MSVD could effectively explore local anomaly features and decompose ore-forming element association anomalies associated with buried mineralization in more detail. The ore-forming element anomaly components can delineate ore-finding Sn-Cu polymetallic deposits more exactly than the ore-forming element association anomalies.

Keywords

singular value decomposition (SVD) / principal component analysis (PCA) / ore-forming element anomaly components / Sn-Cu polymetallic ore-finding targets / Gejiu Sn-Cu ore field / SW China

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