3D models for hydrothermal copper ore bodies at Sin Quyen deposit, North Vietnam: A case report for ore reserves and prediction of hidden mineral resource potential.

The complex iron oxide copper and gold (IOCG) Sin Quyen deposit in northern Vietnam is known as hydrothermal veins and multi-stages of mineralization. Thus, it is complicated to make a probabilistic 3D geometric model using traditional methods and to predict the hidden mineral potential. In this study, computer modeling with nearly 8000 archival data was recorded from 146 boreholes within the study area, and the chemical analysis was done on 40 samples. The 3D block model was constructed using geological structure, optimal parameters, and computational tools approach to the 3D geometric models of surface and ore bodies distribution. The Cu and Ag reserves were estimated based on the 3D geometric models. The total reserve of all ore bodies at the current depth was recorded at 540000 and 25 tons for Cu and Ag, respectively. In the study area, almost all ore bodies were observed as hydrothermal vein types, extending in Northwest-Southeast strikes and dipping around 750 m, closest to the geological observation. The mineralization characteristics of the study area are controlled by left-lateral zipper tectonic activity and faults. Based on tectonic and the 3D geometric model characteristics, the Cu ore bodies are trending continuously to more than 300 m depth at the Southeast of Ngoi Phat stream, while the Northwest shows no signs.