四川里伍铜多金属矿床构造变形特征及其控矿规律研究

发布时间：2018-06-13 06:06

本文选题：构造控矿 + 构造演化　；参考：《成都理工大学》2017年硕士论文

【摘要】：研究区大地构造位置位于扬子地台西南缘,木里—锦屏山弧形推覆构造带北西侧。区域构造运动强烈,成矿条件优越,矿产资源丰富,矿区成矿与构造关系密切。通过对研究区构造类型和构造控矿特征的研究,结合区域地质背景,探讨其构造变形特征和构造控矿规律。(1)研究区地层主要为早元古界里伍岩群的云母片岩、云母石英片岩、云母石英岩、石英岩。区内构造变形强烈,矿区地层经历多期变质变形作用,发育三期以上构造面理,宏观面理构造置换现象明显,S2面理为里伍岩群主期构造面理,构造变形以韧性、脆-韧性变形为主。(2)研究区主要有面理构造、断裂构造、褶皱构造三种构造控矿类型。面理主要为含矿溶体提供通道和容矿空间。断裂构造是成矿过程中的岩浆和热液的通道,但往往只是在断裂的某些有利部位才有矿田及矿床的产出。褶皱构造常控制着矿田及矿床的分布,无论是背斜轴部、向斜轴部还是褶皱冀部都可有矿床的产出。(3)矿区主要经历了四级构造变形应力作用。第一级为海西期WE向的伸展作用,区内形成紧闭褶皱、石香肠构造、顺层韧性剪切带等水平剪切构造;第二级为印支期WE向和SN向的双向挤压作用,区内形成不对称褶皱、平卧褶皱、逆冲推覆构造等;第三级为燕山期NNW-SSE向的挤压作用,区内构造表现形式以层间断裂和层间滑动为主;第四级为喜山期WE向的挤压作用,区域内主要形成逆冲推覆构造、高角度逆断层和表层脆性变形等变形。(4)矿床的最终形成于燕山期—喜玛拉雅期的造山碰撞阶段,区域内发生多层次的伸展剥离,结合矿区构造控矿特征,成矿物质来源,认为矿区成矿作用受晋宁晚期—澄江期区内发生强烈的造山褶皱作用和碰撞型岩浆活动的影响,导致地壳部分重熔,地幔岩浆大量上涌将成矿物质带到地表或浅地表。在燕山期—喜玛拉雅期的造山运碰撞运动,使地层中成矿物质重新活化,以岩浆一热液方式运移,在构造驱动下运移到有利赋存空间成矿。
[Abstract]:The tectonic location of the study area is located in the southwest margin of the Yangtze platform and the western side of the arc nappe belt in Muli-Jinpingshan. The regional tectonic movement is strong, the ore-forming conditions are superior, the mineral resources are rich, and the ore-forming is closely related to the tectonics. Based on the study of structural types and structural ore-controlling characteristics in the study area and in combination with the regional geological background, the structural deformation characteristics and tectonic ore-controlling regularity of the studied area are discussed. The strata in the study area are mainly mica schist and mica quartz schist of the early Proterozoic Liwu Group. Mica quartzite The tectonic deformation in the area is very strong, the strata in the mining area undergo multi-stage metamorphism and deformation, and there are more than three stages of tectonic facets developed, and the phenomenon of structural replacement of macroscopic facets is obvious that the S 2 plane is the main tectonic plane of the Liwu Group, and the structural deformation is tenacity. There are three types of ore-controlling structures in the study area, I. e., plain structure, fault structure and fold structure. The surface texture mainly provides the passage and the ore-bearing space for the ore-bearing solution. Fault structure is the channel of magma and hydrothermal fluid in the metallogenic process, but it is only in some favorable parts of the fault that ore fields and deposits are produced. Fold structure usually controls the distribution of ore fields and deposits. The ore deposits can be produced in the back inclined axis, the inclined axis or the fold Hebei part. The ore area mainly experienced the four grade tectonic deformation stress. The first stage is the extension of the Hercynian period we direction, the area forms the closed fold, the stone sausage structure, the bedding ductile shear zone and so on horizontal shear structure, the second stage is the Indosinian period we and SN direction bidirectional compressions, the area forms the asymmetry fold, The third stage is the compression of NNW-SSE direction in Yanshanian period, the main form of structure in this area is interlayer fault and interlayer slip, the fourth stage is the compressional action of we direction in Xishan period, the third stage is the compression of NNW-SSE direction in Yanshanian period, and the main structural form in this area is interlayer fault and interlayer slip. The thrust-nappe tectonics, high-angle thrust faults and brittle deformation of the surface layer, etc., were formed in the Orogen collision stage of the Yanshanian to Himalayan epoch, and the multi-level extension and stripping occurred in the area. Based on the ore-controlling characteristics and the source of ore-forming materials, it is considered that the ore-forming process is influenced by the intense orogenic fold and collisional magmatic activity in the late Jinning and Chengjiang period, which leads to the partial remelting of the crust. Massive upwelling of mantle magma brings ore-forming materials to the surface or shallow surface. During the Yanshanian to Himalayan orogenic collision movement, the ore-forming materials in the strata were reactivated and transported in magmatic hydrothermal mode, which were driven by tectonics and migrated to favorable ore-forming space.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.2

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