滇东晚二叠世“煤系铌-镓-稀土矿床”火山灰-热液耦合成矿动力学驱动机制

滇东晚二叠世煤中铌、镓和稀土等多种关键金属超常富集，属于火山灰-热液混合型新型矿床，其资源量巨大，经济价值超高，但此矿床火山灰-热液耦合成矿动力学驱动机制还不清晰。本课题以滇东晚二叠世“煤系铌-镓-稀土矿床”为研究对象，利用XRF、XRD、EPMA、LA-ICP-MS等测试技术，运用地球化学、矿床学和成矿动力学等学科理论，从研究区周围物源性质、火山活动、热液流体等多种地质因素并结合峨眉山地幔柱演化历史，探明该矿床火山灰的物源、建立该区域含煤岩系的精确时间序列，恢复物源区的火山活动历史，揭示原始岩浆起源、性质、形成过程和成矿背景，构建研究区成矿的动力学模型；查明由火山灰-热液流体性质和物理化学条件控制的铌、镓、稀土等关键金属动力耦合成矿过程及动力驱动机制，建立区域铌-镓-稀土矿成矿模式。研究成果不仅能够丰富稀有金属成矿动力学理论，而且可以为滇东地区晚二叠世地质历史演化提供证据。

Many kinds of critical metals such as Nb, Ga and REE are very enriched in Late Permian coal-series in East Yunnan Province. These ore deposits are volcanic ash-hydrothermal fluid coupling and the indicated resource of these ore deposits is huge and the economic value is very high. While the driving mechanism of coupling metallogenic dynamics of volcanic ash-hydrothermal fluid of these ore deposits is not clear. In this project, we take the Late Permian “Nb-Ga-RE ore deposits in coal-series” in East Yunnan Province as research object. We use testing technologies such as XRF, XRD, EPMA and LA-ICP-MS and we use theories such as geochemistry, ore deposit geology and metallogenic dynamics. We will study the multiple geological factors of the research area such as provenance characteristic, volcanic activity, hydrothermal fluid and the history of mantle plume evolution of Mount Emei and we want to ascertain provenance area of the Nb-Ga-RE ore deposits in coal-series and establish exact timing sequence of the coal-series in the study area. We want to recover the history of volcanic activities in the provenance area and reveal origin, property, forming process and metallogenic setting of the initial magma. We want to build metallogenic dynamics model and reveal deep dynamics process of the provenance area. We want to find out the coupling mechanism of multiple critical metals such as Nb, Ga and RE, which is controlled by the characteristics of volcanic ash-hydrothermal fluid and the physico-chemical conditions and establish the metallogenic model of these critical metals. These research results will enrich metallogenic dynamics theory of rare metals and they will provide new evidences for the evolution of Late Permian geological history of East Yunnan Province.