Local singularity and S–A methods for analyzing ore-producing anomalies in the Jianbiannongchang area of Heilongjiang, China.

The Heilongjiang Jianbiannongchang area is located at the confluence of the Great and Lesser Xing'an Ranges. This area has a complex magmatic and tectonic evolutionary history that has resulted in a complex and diverse geological background for mineralization. In this study, isometric logarithmic ratio (ILR) transformations of Au, Cu, Pb, Zn, and Sb contents were performed in the 1:50,000 soil geochemical data of the Jianbiannongchang area. Robust principal component analysis (RPCA) was conducted based on ILR transformation. The local singularity and spectrum-area (S-A) methods were used to extract information on mineralogic anomalies. The results showed that: (1) the transformed data eliminated the influence of the original data closure effect, and the PC1 and PC2 information obtained by applying RPCA reflected ore-producing element anomalies dominated by Au and Cu. (2) The local singularity method can enhance the information of the local strong and weak slow anomalies. After performing local singularity analysis on PC1 and PC2, the obtained local anomalies reflected the local singularity spatial anomaly patterns related to Cu and Au mineralization in this area, which is an effective method for trapping ore-producing anomalies. (3) Furthermore, the composite anomaly decomposition of PC1 and PC2 was performed using the S-A method, and the screened anomalous and background fields reflect the ore-producing anomalies related to Cu and Au mineralization. This information is in agreement with known Cu and Au mineralization. (4) The geochemical anomalies with mineralization potential were obtained outside the known mineralization sites by integrating the information of ore-producing anomalies extracted by the local singularity and S-A methods, providing the theoretical basis and exploration direction for future exploration in the study area. [ABSTRACT FROM AUTHOR]