3D geological modeling using Cu grades of the Archean Horne VMS deposit (Blake River Group, Quebec) and beneficiations to the genetical model

The Archean Horne deposit in the Noranda District, Quebec, Canada, is one of the world’s largest volcanic massive sulfide (VMS) deposits, which has high economic benefits. Compared to other deposits in the Noranda region, Horne deposit has higher grades and huge storage of Au and Cu. Previous researches mostly focused on two-dimensional characteristics and statistical data, which cannot directly reflect the spatial structures and features of the Horne orebody. Therefore, in this paper, we used the GIS software to digitize the outline curves of massive sulfide and Cu grade values from paralleled level-plans and stope maps. Meanwhile, the spatial database of grade property was established. Based on the above results, the three-dimensional (3D) geological model and grade property model of the Horne orebody were established by software of Geological Object Computer-Aided Design (Gocad). According to the established 3D model of this paper, the spatial structure of the Horne orebody was analyzed and the existence of the ancient main faults cutting the Upper and Lower Horne orebodies was further speculated. Due to the function of main fault and spatial distribution of Cu grade in the 3D Cu property model, the position of hydrothermal vents of the Upper and Lower Horne orebodies and the direction of hydrothermal alteration inside the orebody were inferred. This paper summarizes the Cu enrichment process of the Horne deposit based on the 3D Cu property model and determination of the alteration zones. Furthermore, with the help of metallogenic geological background of the Horne deposit, it further explains that the hydrothermal mineralization model of Horne deposit is sericite-chlorite alternate alteration.