Numerical simulation-based targeting of the Au mineralization within the Hongbu Altered Rock type gold deposit, Eastern Shandong Peninsula, China

Abstract

Altered rock type deposits are significant gold deposits widely distributed throughout the world, having important economic and industrial value. The Eastern Shandong Peninsula is the third largest gold mining camps in the world with known gold reserves of more than 5300 tons. The majority of the gold deposits here are located in three main orefields, namely the northwest Jiaodong (Laizhou-Zhaoyuan), the Qixia-Penglai-Fushan, and the Muping-Rushan orefields. The Hongbu deposit is a medium-sized altered rock type deposit within the northwest Jiaodong orefield. With decades of mining, the Hongbu deposit faces the dilemma of resource depletion and loss of undigitized data. Therefore, prospecting and exploration have to focus on deep and peripheral areas of known Au mineralization. This study built a three-dimensional model of the Hongbu deposit and sliced it to obtain nine cross-sections to conduct multi-field coupled numerical simulation (including heat conduction, fluid migration, chemical reaction, and material migration). Locations with relatively developed Au mineralization (the top 15 % within the concentration range of Au) are defined as having metallogenic potential, which are highlighted and projected to the geological map of the Hongbu district. The results also show that the spatial distributions of Au mineralization within these nine sections are different, indicating that the formation of Au mineralization is controlled by the morphology of the Hexi fault (other simulation parameters of these nine sections are the same) and the pyrite sericite cataclasite. This research proves that numerical simulation methods is effective in mineral exploration, especially for those areas with insufficient data to use data-driven prospectivity modeling approaches. Future development into both mathematical geosciences and computational science will provide more detailed answers for remaining hot issues related to mineral exploration.