胶东金牛山金矿床构造-流体-成矿作用体系研究

通过对胶东金牛山金矿床构造变形和流体包裹体的研究,探讨了矿床的形成过程和流体成矿机理,认为本区经历了多期构造变形演化,并伴有多次脉动式热液活动,金牛山断裂总体上控制流体来源、运移和沉淀。第二构造变形期早阶段,热液来源以大气降水为主,而中 晚阶段为大气降水和岩浆水;断裂带中流体异常活跃,局部有高压流体存在,产生水压致裂作用;构造变形引起流体的沸腾、混合和相分离作用,并使流体成份和性质发生变化,导致金的沉淀。因此,构造和流体的共同作用控制了矿床的形成,而异常流体叠加控制了富矿体的形成。在此基础上总结了金牛山金矿床形成的构造—流体—成矿作用体系模式。

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.