胶东焦家金矿田超深部流体-蚀变与金富集机理 —依托于3000米科研深钻

The deep ore-forming process research of Northwest Jiaodong gold mineralization belt has become a hot research spot that drew worldwide scientists' attention. Deep scientific drilling is the most effective method to research the alteration and mineralization of deep structural belt, and it’s why we are implementing a 3,000 meters scientific drilling in Jiaojia gold metallogenic belt. We have obtained lots of first-hand materials and rock samples, they are crucial during researching the deep mineralization process. Combined with the ultra-deep scientific drilling, this research revolving this center of the ultra-deep fluids- alteration and the mechanism of gold enrichment, and mainly focus on the following research: ⑴ Find out the deep tectonic characteristics of Jiaojia fault zone; ⑵ Study the mineralization vertical zoning characteristics; ⑶ Summarize the deep mineralization enrichment regularity; ⑷ Discussed the sources of ore-forming materials, migration and precipitation of metallogenic processes; ⑸ Comprehensive study on the activization, transportation, concentration of the gold-carrying minerals so as to set up a deep comprehensive metallogenic model and prospecting model of Jiaojia metallogenic belt. Obviously, This project will help to understand the ultra-deep fluids- alteration and the mechanism of gold enrichment of Jiaojia gold field in Jiaodong area. This achievement in research would provide important information for further research and prospecting of such deposits.

胶东金矿深部成矿过程研究一直是国内外研究的焦点，而科研深钻是研究深部结构、蚀变、矿化特征最直接有效的手段。继三山岛断裂带深部实施的4016米超深钻探之后，本项目组2016年始斥巨资在焦家断裂带深部也实施了3000米超深科研钻探，取得了第一手的焦家深部资料，这对深入研究焦家这个千吨级巨型金矿床超深部流体-蚀变与金富集过程，指导深部勘查意义重大。本项目将依托于正在施工的3000米科研深钻和已有的2200米等勘查钻孔，紧紧围绕深部流体-蚀变与金富集机理这个中心，查明深部控矿构造特征；研究玲珑花岗岩的垂向变化特征；总结深部矿化富集规律和矿化垂向分带特征；探讨成矿流体和成矿物质来源、迁移和沉淀成矿过程；建立焦家成矿带深部综合成矿模式和找矿模型。这项工作将为我国深部成矿地质学研究提供极好的基地和范例，会极大地推动深部控矿构造特征、赋矿蚀变带存在部位及蚀变岩型金矿延长深度等深部找矿重大科学问题的解决。

本项目严格按照项目设计的总体思路，完成了项目设计的全部工作任务。通过详细的岩相学、矿物学观察分析，揭示了焦家金矿带3000米深度垂向上的金矿化蚀变分带特征，明确了金矿床（体）赋存规律和深部找矿方向；通过开展系统的花岗岩地球化学和年代学研究，明确了区域中生代岩浆活动对成矿作用的制约，并发现了胶西北东部110Ma金矿成矿事件的线索；通过系统开展流体包裹体研究，梳理了成矿过程中岩浆-热液流体的演化规律及其对成矿的贡献；通过金矿原生晕地球化学研究，确定了新的深部找矿靶区和找矿方向；首次通过系统梳理胶西北地区岩浆岩岩石微量元素的大数据变化规律，确定了中生代壳幔岩浆的混合反应是巨量金质来源的关键，丰富发展了胶东金矿的成矿理论。在此基础上研究预测了深部金矿资源潜力及找矿方向，指导深部找矿工作部署，为今后相似地区的工作提供示范。