A study on structure fluid-mineralization system in the Jinniushan gold deposit, East Shandong

Based on tectonic deformation and fluid inclusions, the ore forming processes and hydrothermal mineralization mechanism of the Jinniushan gold deposit in east Shandong were discussed. The studied region experienced a multi-phase of deformations, accompanying multi-stage of hydrothermal activities successively. The sources, transportation and deposition of the hydrothermal fluids were controlled by the Jinniushan fault. During the early phase of deformation, the solutions mainly originated from meteoric water. During the later phase of deformation, magmatic water predominated gradually. There were active and pulsating fluids in the fault zone, and high-pressure fluids existed in local and produced hydraulic fracturing in the fault zone. The tectonic deformation resulted in fluid boiling, mixing and phase separation processes of the hydrothermal solutions, which caused, in turn, the changes of composition and feature, as a result, the solubility of the gold-bearing complexes lowered sharply and gold deposition created. Therefore, the formation of gold deposit were controlled together by the structure and fluid, the formation of the rich ore bodies were controlled by the stacked high-pressure fluids. Base on this study, the systematic evolution model of stucture-fluid-mineralization for the Jinniushan gold diposit was summarized.