- 1Frontiers Science Center for Deep-time Digital Earth, State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences and Resources, China University of Geosciences, Beijing, China
- 2Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
- 3Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
Granite-hosted gold deposits, a major component of global gold resources, exhibit complex geochemical evolution and diverse mineralization types. Understanding the mechanisms of gold precipitation and enrichment in these systems is crucial for mineral resources exploration and extraction. Alteration processes such as potassic alteration, sericitization and pyritization significantly influence gold mobility and concentration. However, their roles in fluid-rock interactions and coupled physical-chemical dynamics remain insufficiently understood due to the complexity of mineralogical and environmental factors, as well as limited experimental and modeling data.
This study employs PFLOTRAN-based reactive transport modeling to explore the geochemical mechanisms of gold precipitation and enrichment, using the Sanshandao gold deposit in Jiaodong Peninsula, China, as a case study. Integrating geological data, hydrothermal fluid dynamics, and thermodynamic of chemical reaction networks, the model explores the influence of alteration minerals, including K-feldspar, sericite and pyrite, on fluid composition, gold solubility and precipitation. It evaluates the effects of critical parameters such as temperature, pressure and PH on the stability and solubility of gold-bearing complexes, revealing the advantageous conditions for gold precipitation.
Alteration minerals affect hydrothermal fluid properties, such as PH and redox potential, which govern gold precipitation. For example, sericitization decreases fluid PH and enhances gold solubility, while pyritization facilitates adsorption, promoting localized gold enrichment. This underscores the importance of fluid-rock interactions and geochemical conditions in controlling gold transport and enrichment.
This study offers a framework for understanding the physical-chemical mechanisms of gold mineralization in granite-hosted gold deposits. The use of reactive transport modeling provides insights how alteration processes and fluid-rock interactions shape ore-forming mechanism similar to geological settings.
Keywords: Granite-hosted gold deposits; Reactive transport modeling; Fluid-rock interaction; Gold precipitation and enrichment; Ore-forming mechanism
How to cite: Cai, Y., Qiu, K.-F., Szymczak, P., Ladd, A. J. C., He, D.-Y., Yu, H.-C., and Cui, T.: Reactive Transport Numerical Modeling of Gold Precipitation and Enrichment of Granite-Hosted Gold Deposit, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-822, https://doi.org/10.5194/egusphere-egu25-822, 2025.
