三江特提斯复合造山与成矿作用研究态势及启示

The situation and enlightenment of the research of the tectonic evolution and metallogenesis in the Sanjiang Tethys

简述了"三江特提斯复合造山与成矿作用"项目的总体框架、研究目标和研究内容,总结了已开展的研究工作和研究进展。项目已在4个方面取得了系列重要进展:(1)通过对缝合带中放射虫硅质岩和基性-超基性岩,以及不同地体内火成岩的年代学和地球化学等研究,构建了三江地区从原特提斯、古特提斯、中特提斯到新特提斯大地构造-岩浆演化格架;(2)通过对VMS型Cu-Pb-Zn,沉积岩容矿型Zn-Pb-Cu-Ag,夕卡岩/斑岩Cu-Au-Mo及多成因类型Au 4种典型矿床类型研究,建立了复合造山过程中成矿系统结构和解析了巨量金属集聚成矿过程;(3)分析了增生造山→碰撞造山、主碰撞→晚碰撞和晚碰撞→后碰撞三期重要构造体制转换事件,提出了叠加成矿作用的3种类型和9种方式;(4)总结提炼了适合"三江"地区的"斑岩成矿系统+模型+高光谱+蚀变矿物填图+高精度磁测+电法"、"成矿模式+层位+瞬变电磁法+激发极化法"、"成矿系统+重+磁+多种电法"等勘查技术方法。

The general framework, targets, and major researches of the project of superimposed orogenesis and metallogenesis in the Sanjiang Tethys are introduced in the paper, this huge project is included in the National 973-Program. The paper also summarized recent research progresses as follows： （1） based on the geochronology and geochemistry of the cherts and the mafic and ultramafic rocks in suture zones, and the igneous rocks within the blocks, the tectonic framework and magmatic evolution from the Protc-Tethys, Palaeo-Tethys, to Meso- Tethys and to Nec-Tethys were proposed; （2） via analyzing four metallogenic systems of VMS CwPb-Zn, sediment-hosted Zn-Pb-Cu-Ag, porphyry and skarn Cu-Au-Mo, and different genetic types of Au deposits, the structures of metallogenic systems were determined and the formation of giant metallogenic domains in the process of the superimposed orogenesis were analyzed; （3） the authors proposed three stages of the transition of tectonic regime （from the accreting orogen to the collisional orogen, from the main collision to the late collision, and from the late collision to the post-collision）, and three types and nine subtypes of the superposed metallogenesis; and （4） the exploration methods and the improvement of critical techniques of resource exploration in the Sanjiang Tethyan Metallogenic Domain were summarized, such as ＂porphyry metallogenic systems＋ metallogenic model 2c high spectrum ＋alteration mineral mapping ＋ high-precision magnetic survey ＋ electrical method＂, ＂metallogenic model＋stratigraphic horizon＋transient electromagnetic method＋induced polarization method＂, and ＂metallogenic systems＋gravity method＋magnetic method＋multiple electrical methods＂.