【作者】 杨夕辉；

【导师】 毛景文；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2010， 博士

【摘要】 “三江”成矿带以其独特的地质构造景观和丰富的矿产资源而闻名于地学界。中甸矿集区(27°41′-28°32′N,99°40′-100°15′E)位于三江中南段义敦岛弧带南段,岛弧演化历经俯冲造山、碰撞造山、后造山伸展、走滑剪切转换造山的构造演化过程,形成了与斑岩铜矿关系密切的印支期中酸性斑岩集中分布区,。本文系统研究了中甸构造岩浆岩岛弧带中酸性斑岩产出地质背景、岩石矿物学、地球化学特征,总结了区域成矿系统:提出区域成矿系统由岛弧(构造)演化、岛弧火山沉积建造、中酸性岩浆活动三大要素组成,其中印支期岛弧中-中酸性浅成-超浅成岩侵入岩浆活动是斑岩铜矿最重要的成矿作用,在不同条件、不同部位形成了不同类型的斑岩铜矿成矿系列。通过区域成矿规律和典型矿床研究,斑岩铜矿成矿具同源岩浆由中性→中酸性→酸性→偏碱性演化的成矿过程,总结该区成矿模式为:深断裂→岩浆同源演化→岩浆+构造+热液蚀变→围岩的封闭条件。通过多学科多方法勘查评价研究,总结提出了适宜高寒地区勘查评价的技术方法,建立了区域斑岩铜矿找矿及勘查评价模式,开展了靶区优选,并在浪泥塘、浪都、高赤坪等靶区找矿取得了重大突破。论文取得如下几个方面的创新成果:1、首次在研究区浪泥塘斑岩铜矿V1—3矿体ZK3—5钻孔岩芯中发现硬石膏(区内的其他矿床尚未发现或未报道)和磁铁矿,且石膏含量与铜品位相关性较强,直观的证明斑岩铜矿原始岩浆属氧化型,有利于斑岩铜矿的形成。提出浪泥塘斑岩铜矿是在高氧逸度条件下形成的富金的斑岩铜矿。2、对普朗超大型和雪鸡坪斑岩铜矿含矿斑岩锆石LA-ICP-MS U-Pb年代学与REE、Hf测定,对岩浆演化及年代进一步确定。3、水系沉积物地球化学异常分析显示,印支期斑岩矿化系统形成Cu-Ag-Sn-Bi幔源异常元素组合,燕山期花岗岩中钨钼矿化系统产生W-Mo-U壳源异常元素组合,该认识有效地指导研究区的成矿预测。4.运用建立的中甸地区斑岩铜矿床模型,结合有效技术方法组合,开展了靶区优选,提出了中甸地区斑岩铜矿找矿新思路更多还原

【Abstract】 “Sanjinag”metallogenic belt is famous of its unique geological landscape and abundant mineral resources. Zhongdian area (27°41’-28°32’N, 99°40’-100°15’E), located in the southern of Yidun island arc, is a ore deposit concentration area. The island arc had undergone the evolution of subduction orogeny, collision orogeny, post-orogenic extensional, tectonic evolution of strike-slip shear transformation orogeny and so on. Zhongdian area is a Indosinian intermediate-acid porphyry (porphyrite) concentrated area. In recent years, we have found a lot of porphyry copper deposits in this ore deposit concentration area.In this text, we point that a proposed regional metallogenic system is composed of island arc (structural) evolution, island arc volcanic-sedimentary construction and intermediate-acid magmatic activity thought a systemic study of geology background of intermediate-acid porphyry (porphyrite), petromineralogy and geochemistry. The Indosinian high-level intermediate-acid magma is the closed with metallogenesis of porphyry copper, which can form different types of porphyry copper deposits series in different conditions and different parts. Based on the study of regional metallogenic regularity and the typical deposit, we point the mineralization process of porphyry copper deposits is intermediate→intermediate-acid→acid→slight alkaline of comagmatic evolution. The mineralization model is deep fault→comagmatic evolution→magma+structure+hydrothermal alteration→cosed condition of surrounding rocks. And then, a new position and forecast of mineralized porphyry body and effective combination of technology and methods for prospecting can be studied in this text. These methods are applied to practice in prospecting in Zhongdian area and a series of results have been got in Lannitang, Langdu, Chundu, Gaochiping.The following aspects are the innovative results of this paper obtained:1. In the study area, we find anhydrite and magnetite in V1-3 ore body and drill core of ZK3-5 of Lannitang porphyry copper deposit (other deposits have not yet found or reported in this area). The content of anhydrite has a strong correlation with copper grade. We prove intuitively the original magma of porphyry copper deposits are oxidized, which is conducive to the formation of porphyry copper deposits. We propose that Lannitang porphyry copper deposit is a gold-rich porphyry copper deposit formed in high oxygen fugacity conditions.2. Stream sediment geochemical anomalies analysis showed that Indosinian porphyry mineralization system can form Cu-Ag-Sn-Bi mantle derived elements and Yanshanian granite molybdenum mineralization system can produce W-Mo-U crustal derived anomalies elements.3. Porphyry copper system will produce significant magnetic anomalies. Aerospace precision magnetic survey results is the most important evidence for forecasting the constituency of metal deposits.4. Clear the function and status of interdisciplinary approach on evaluation of mineral resources in Zhongdian Area, and then comprehensively analyze, delineate prospecting targets and organize resources exploration and evaluation.更多还原