摘要
通过对胶东金矿地质背景和成矿特征研究的总结与分析,依据热液矿床水相变控矿理论,探索胶东地区高密度聚集巨量金矿的原因。研究发现,两期次降压驱动成矿物质运动和临界水的(温度和压力都达到水临界值时的水,下同)特殊性质是两个重要因素。在此基础上,文章提出胶东巨量金聚集成矿的深大断裂-临界成矿机制,即“一饼加一刀”的成矿机制:老变质岩提供丰富的成矿物源是基础;早期大型点状降压形成酸性侵入杂岩体和各类岩脉等,其伴生的长时间、巨量临界水促使成矿物质活化迁移;晚期大型线状断裂降压造成较短时间内成矿物质的沉淀,若断裂是张开的不连续空间则矿石以充填结构为主,若破碎带是连续空间时矿石则以蚀变交代结构为主。丰富的金源,两期次不同性质的降压,临界水的独特性质,是胶东巨量金矿聚集的主要因素。
This study aims to study the reason why a huge accumulation of gold deposits occurred in the Jiaodong area.We summarized and analyzed the geological background and metallogenic characteristics of the Jiaodong gold deposits.In parallel,we highlighted the importance of depressurization-driven movement of ore-forming materials at two stages and the special properties of critical water(water at the critical value of both temperature and pressure,the same below)based on the theory of water phase change controlling metallogenesis in hydrothermal deposits.The above analysis results allow us to propose the Mesozoic massive gold metallogenic mechanism of deep-large fault coupling with critical water in the Jiaodong area,that is,the metallogenic mechanism of“one cake plus one knife”.The old metamorphic rocks provide abundant ore-forming materials.In the early stage,a large-scale point-like depressurization results in acid intrusive complexes and various dykes,which were accompanied by a large amount of critical water over a long time to promote the activation and migration of ore-forming materials;In the late stage,the depressurization of the large linear fault caused the precipitation of ore-forming materials in a short time.The faults with open discontinuous space are dominated by ore-filling structures,while the fracture zones with continuous space are dominated by mineralized alteration with metasomatic structures.Abundant gold in metamorphic rocks,two stages of depressurization with different properties and unique properties of critical water are the main factors for the accumulation of massive gold deposits in the Jiaodong area.
作者
胡宝群
高海东
王运
张宝林
吕古贤
HU Baoqun;GAO Haidong;WANG Yun;ZHANG Baolin;LYU Guxian(School of Earth Sciences,East China University of Technology,Nanchang 330013,Jiangxi,China;School of Architectural Engineering,Nanchang Institute of Science and Technology,Nanchang 330013,Jiangxi,China;Key Laboratory of Mineral Resources Research,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China)
出处
《地质力学学报》
CSCD
北大核心
2021年第4期585-595,共11页
Journal of Geomechanics
基金
国家自然科学基金项目(41472069)。
关键词
降压
构造控岩控矿
成矿机制
金矿床
胶东
depressurization
structural control on rock and ore
metallogenic mechanism
gold deposit
the Jiaodong area
