地幔柱与俯冲带相互作用研究：滇东南二叠纪火山岩为例

地幔柱构造和俯冲构造一般被认为是地球系统中两个独立的构造体系，但它们在不同时空尺度的耦合现象又暗示两者之间可能是紧密联系、相互作用的，查明它们之间相互作用的方式和过程对于理解地球系统的演化具有重要意义，是地球科学研究热点之一。华南板块西南缘滇东南地区受到古特提斯哀牢山洋俯冲（尤其是新识别出的东向俯冲）和峨眉地幔柱的双重影响，是我国研究古地幔柱和古俯冲带相互作用过程的最理想地区。区内滇东南红河-建水地区出露一套二叠纪火山岩，其成因和动力学背景还存在很大争议。本项目拟针对该套火山岩进行系统的野外地质考察、年代学、岩相学、主微量元素和Sr-Nd-Hf-O-B-Mo同位素地球化学的研究，示踪其源区地幔性质和组成，尤其是流体活动性组分在穿岛弧方向上的时空变化规律，查明其岩石成因和动力学背景，从而揭示古特提斯俯冲带与峨眉山地幔柱潜在的相互作用过程及岩浆响应，有效限制华南板块西南缘晚古生代构造演化历史。

Mantle plume and subduction zone are generally regarded as two independent tectonic system of the Earth, but the coupling phenomenon in different time and space scales between them implies that they might be closely related and interacted. Identifying the detailed process of interaction between them is of great significance to understand how the Earth works, which is one of hot spots of the earth science research. Southeast Yunnan (southwestern margin of South China) is located at the junction region between the Paleotethyan Ailaoshan oceanic subduction zone and the Emeishan mantle plume, which provides us an opportunity to study the interaction between ancient mantle plume and subduction zone in China. The petrogenesis and geodynamic background of the exposed Permian volcanic rocks in this region remain controversial. This project intends to make integrated field geological investigation, detailed chronology, petrography, major and trace elements and Sr-Nd-Hf-O-B-Mo isotope geochemistry of the Permian volcanic rocks in Red River and Jianshui area of southeast Yunnan, which aims to trace the mantle properties and source composition, especially the fluid mobile components variations with space and time on across-arc direction. This research will help revealing the processe of Emeishan mantle plume-Paleotethys subduction potential interaction and related magmatism, and thus effectively constrain the Late Paleozoic geodynamic process of southwest margin of South China Block.