3D Block Modelling of the Sin Quyen IOCG Deposit, North Vietnam

The IOCG Sin Quyen deposit is located in the Red River shear zone of North Vietnam. The ore bodies are known as hydrothermal veins and are hosted in Proterozoic metapelite. A block modelling approach was used to build a 3D model of the ore bodies. An analysis was carried out on SurferR 11 computer software using the archival data recorded from several dozen boreholes distributed within the study area, as well as data obtained from the mineral and chemical analysis of 50 samples collected recently in the deposit. The ore bodies generally trend in a NW-SE direction with an average azimuth of 107° and a dip of around 70°.  Cu content in the ore bodies is inhomogeneous. In the bed extension direction, the exponential correlation of Cu concentration in ore bodies is recognized within 2,500 m, while in the direction perpendicular to the bed strike, the exponential dependence is observed at 500 m of distance. The high-grade mineralisation of copper within the ore bodies is often at the altitude interval from ∼100 m to ∼150 m above sea level (asl). These bodies are also rich in uranium and gold-bearing minerals. The total resources of Cu, U and Ag were estimated and amounted to 361,000; 12.7 and 11.87 tonnes respectively. The model indicates the downward extension of some ore bodies to below 300 m beneath the ground surface.