【作者】 张杨；

【导师】 高光明；

【作者基本信息】 中南大学 ， 构造地质学， 2011， 硕士

【摘要】 Donjavier斑岩铜矿床位于东太平成矿带,智利-秘鲁斑岩铜矿矿集区。其构造和岩浆活动深受纳兹卡板块向南美板块俯冲的影响。本文主要对Donjavier斑岩铜矿床的地质特征进行了研究。通过野外工作,基本查明矿区的地层、构造、岩性以及矿化分布特征。在对研究区地质、物探、化探等资料进行综合分析的基础上,取得了以下主要认识：1、通过对研究区断裂进行统计,证实研究区构造格局与区域构造格局基本一致。并提出北西向构造为研究区重要的导矿、容矿构造,北东向为主要容矿构造。矿体主要产于北西向和北东向构造交汇处。2、对研究区各类岩浆岩进行了镜下鉴定。得出含矿斑岩为英安斑岩,围岩属于Yarabamba超单元的花岗岩类。并观察到镜下斜长石普遍被交代成绢云母,含矿性越高蚀变越强。3、经过野外观察和光薄片研究,初步将研究区成矿划分为三期五阶段。分别为：斑岩期；热液期；表生期。成矿主要在斑岩期,而热液期主要对矿体叠加富化,表生期在研究区不构成工业矿体。4、认为研究区存在典型的斑岩铜矿蚀变分带和矿化分带现象。蚀变分带主要沿北西向呈线性展布,每个蚀变带有对应的矿物组合。其中青磐岩化蚀变分布最广,在岩芯中也最常见。硅化带是含矿性最高的蚀变带,其次是绢英岩化带。泥化带有较高的金含量。5、对研究区的地表化探数据进行了统计学分析。并依据元素相关关系生成了化探等值线图。对研究区的地球物理资料进行分析和总结,概括出矿致异常的特征。6、提出了Donjavier矿区的雏形断裂成矿模型,认为研究区可能是受雏形断裂控制的透镜状矿体。其形成主要受张性构造空间对岩浆的虹吸作用和区域剪切应力双重影响。7、对研究区及其周边勘探提出建议。在Donjavier矿区划分出了浅部找矿预测区,角砾岩型找矿预测区和深部找矿预测区。对邻区Cercana矿区进一步工作提出建议,并认为存在较好的角砾岩筒型金矿的找矿前景。更多还原

【Abstract】 The Donjavier porphyry copper deposit is located in the east Pacific Coast belt, the Chili-Peru ore-concentrated area, whose formation and magmatic activities are heavily effected by Nazca plate’ s subduction to the South American plate. This paper mainly studied the geological characteristics of Donjavier porphyry copper deposit, and it has been basically found out the mine stratum, structure, lithology and distribution of mineralization through the field work. With the comprehensive analysis on the research area’ s data of geology, geochemistry and geophysics etc., the primary achievements have been obtained in this paper as following:1. It has been proved by faults statistic in Donjavier deposit that the structure of the research area is roughly consistent with the regional tectonic framework. Meanwhile, it is recognized the NW as the important principal passable structure and host structure, and the NE as the major host structure. The ore body is mostly formed in the structural intersection of the NW and NE.2. Various types of magmatic rocks in the research area were identified under microscope. It is reaches that the porphyry dacite is ore-bearing rock, while the wall rocks are the Yarabamba super-unit. Also, plagioclases are observed to be altered to sericite. The more mineralized, the stronger altered.3. By studying the characteristics of the ore texture and ore structure under microscope and field observation, the deposit can be previously divided into three metallogenic periods (first porphyry period in which the metal are formed; second breccia period in which the ore shoot is formed, finally hypergene period in which no industrial ore body is formed) and five metallizing stages.4. The research area shows a typical porphyry copper line alteration zoning and mineralization zoning. The line zoning is altered along the NW direction, and each alteration corresponds to different mineral assemblage. Among them, the propylitic is the most widely distribution alteration type and can be easily found in the drill core. The main ore-bearing alteration zone is silicified zone, and then is phyllic. Argillic zone contains higher gold content.5. The statistics analysis method was adopted to process the surface geochemical data in the research area and made the geochemical exploration equivalence graph according to the element relationship. It also analyzes and summarizes the geophysical data in the research area, concluding the characteristics of abnormal mineralization.6. This paper has put forward the metallization model about the embryonic fracture, and reckons that the research area is probably a lenticular ore body controlled by embryonic fracture, whose formation is mainly due to the double effect of the syphonage of the extensional structure zoom to the magma and the aerial shear stress.7. This paper makes the suggestion about the exploration in the research area and all rounds. It is devided into the superficial exploring prediction area, breccia type exploring prediction area and deep exploring prediction area. And the suggestion is also made about the further work of the adjacent Cercana deposit, where is considered to a place holding the prospect for the breccia type gold mine exploring.更多还原