Geochemical anomalies of critical metals in the Eastern Kunlun Orogenic Belt, China: Implications for nickel and cobalt mineral exploration
Yue Liu, Qinglin Xia, Jianhua Duan, Jiawen Dai, Sijian Wu, Zhengguang Zhao
Abstract
The demand for critical metals Ni and Co is proliferating all over the world, while critical metal supply in future is still uncertain because of the difficulty in discovering new deposits by using traditional methods. The Eastern Kunlun Orogenic Belt (EKOB) stands as a significant metallogenic domain within the western part of the Chinese Central Orogenic Belt. Since the discovery of the Xiarihamu super-large Ni-Cu-Co deposit, it has triggered a surge in intensified efforts to explore cobalt and nickel deposits. Cobalt and nickel deposits can be roughly grouped into two genesis types in the EKOB: (i) magmatic Ni-Co sulfide deposit, and (ii) hydrothermal Co polymetallic deposit. In this study, the targeted Ni-Co mineralization-related geochemical anomalies were recognized from different perspectives by using multiple advanced feature extraction methods. The centered log-ratio transformed method was used to eliminate the closure effect of compositional geochemical data. Local singularity analysis was applied to recognize weak and concealed Ni and Co i anomalies from the perspective of multifractal. Clustering analysis and compositional balance analysis were employed to reveal Ni-Co mineralization-related multi-element combination pattern and construct interesting compositional balances for anomaly mapping. Then, concentration-area fractal model was used to separate Ni-Co anomaly from compositional balance maps. According to the results of Ni-Co anomaly recognition, different genesis types of Ni-Co deposits were investigated, and favorable prospect zones were delineated to explore magmatic Ni-Co sulfide deposit and hydrothermal Co polymetallic deposit in the EKOB.