西昆仑昆盖山火山岩构造环境与典型矿床研究

发布时间：2018-06-16 06:48

  本文选题：火山岩 + 构造环境　； 参考：《中国科学院研究生院(广州地球化学研究所)》2016年博士论文

【摘要】：西昆仑造山带自南向北依次分为喀喇昆仑地体、甜水海地体、南昆仑地体和北昆仑地体。北昆仑地体与塔里木块体的结合带大面积出露一系列晚古生代火山岩,展布于昆盖山北坡盖孜-库地-上期汗一线,从西昆仑山的西部一直绵延至西昆仑山的东部,长达数千公里。此晚古生代火山岩带发育一系列中小型VMS矿床,阿克塔什铜-金矿床、萨洛依铜矿床为其中最具有代表性的矿床。本文以阿克塔什铜-金矿床和萨洛依铜矿床为研究对象,在系统的总结矿床地质特征的基础上,结合对赋矿火山岩的研究,深入探讨成矿构造环境、成岩成矿时代、成矿物质来源,分析矿床成因类型,建立成矿模式。主要取得了以下认识和成果:1通过对阿克塔什火山岩、萨洛依玄武岩和盖孜安山岩的锆石U-Pb年龄的系统分析得到,西昆仑地区昆盖山北坡-盖孜一带原划分为石炭纪的火山岩,形成时代应该为早二叠世和晚二叠世。阿克塔什火山岩的年龄为284.6Ma,萨洛依玄武岩的年龄为263.0Ma,盖孜安山岩的年龄为263.8Ma。2阿克塔什火山岩发育在岛弧扩张的初期,为一套岛弧拉斑性质的双峰式火山岩和钙碱性玄武岩。盖孜安山岩和萨洛依玄武岩为相对晚期的具有N-MORB性质岛弧玄武岩和岛弧安山岩,二者的成岩年龄近乎相同,由此推测盖孜安山岩可能与萨洛依玄武岩为同套火山岩。阿克塔什火山岩到萨洛依玄武岩-盖孜安山岩的岩石地球化学特征的变化,反映此套火山岩产出的大地构造环境处于岛弧向弧间(后)盆地的过渡阶段。3通过对阿克塔什铜-金矿床赋矿围岩的岩石地球化学特征的研究,认为阿克塔什矿床的赋矿围岩可以与西太平洋日本冲绳岛弧产出的块状硫化物矿床的赋矿围岩相对比,萨洛依铜矿床的赋矿围岩为枕状构造的拉斑玄武岩,与塞浦路斯型矿床的围岩类似。4对阿克塔什铜-金矿床和萨洛依铜矿床分别进行了详细的矿床地球化学(矿石地球化学、围岩地球化学、S同位素)研究,各项证据均表明阿克塔什铜-金矿床的成矿物质主要来源于火山岩,萨洛依铜矿床的成矿物质来源于火山岩和海洋沉积物。5通过对阿克塔什、萨洛依铜矿床中的硫化物主微量元素的分析,矿体从下盘到上盘具有明显的分带规律。据此将阿克塔什矿床与萨洛依铜矿床的成矿过程分别分为三个“阶段”。阿克塔什铜-金矿床的成矿过程依次为火山喷气“阶段”、火山热液沉积“阶段”、含矿热卤水+火山热液沉积“阶段”;萨洛依铜矿床的成矿过程依次为富矿热卤水沉积“阶段”、热卤水沉积+火山热液沉积“阶段”、含矿热卤水沉积“阶段”。6阿克塔什矿床的硫主要来自于岩浆喷气作用,萨洛依矿床为多硫源成因,硫可能为海水硫、火山喷气硫和沉积硫的混合。7同沉积的块状硫化物矿床的形成时代与火山岩的形成时代一致。所以,阿克塔什铜-金矿床的成矿时代为早二叠世,萨洛依铜矿床的成矿时代为晚二叠世。8阿克塔什铜-金矿床中黄铁矿的Re-Os同位素年龄与围岩年龄存在一定的差异,本次认为黄铁矿的Re-Os体系可能已不满足同源性条件,但保留对黄铁矿Re-Os年龄的探讨。有可能阿克塔什矿床的东矿区地层为库地-奥依塔克蛇绿岩套的残片,对东矿区的地层接触关系还需要进一步研究。9将阿克塔什矿床和萨洛依矿床同典型的块状硫化物矿床类型进行对比,二者均为典型的与火山作用相关的VMS矿床,矿床成因类型分别为别子型块状硫化物矿床和塞浦路斯型块状硫化物矿床。10西昆仑地区晚古生代发育在扩张岛弧环境的双峰式火山岩、基性火山岩与上覆沉积岩相接触的具有强烈蚀变的地层,是西昆仑地寻找VMS矿床的的重点层位,在地表常常形成铁帽和黄钾铁矾带。
[Abstract]:From south to north, the West Kunlun orogenic belt is divided into Karakoram earth, sweet water Haiti body, southern Kunlun earth body and Northern Kunlun earth body. A series of Late Paleozoic volcanic rocks are exposed in a large area of the northern Kunlun terrain and Tarim block, which is spread to the Khan Khan - Khan frontline of the north slope of the kungshan mountain and extends from West Kunlun Mountains to the West. The eastern part of Kunlun Mountains is a few thousand kilometers long. This late Paleozoic volcanic rock belt developed a series of small and medium sized VMS deposits, the cuprash copper gold deposit and the San Luo Yi copper deposit as the most representative deposit. This paper is based on the study of the cuprash copper gold deposit and the salt copper deposit as the basis of the systematic summary of the geological characteristics of the deposit. On the basis of the study of ore bearing volcanic rocks, the metallogenic tectonic environment, the age of diagenesis and mineralization, the source of metallogenic material, the analysis of the genetic types of the ore deposits and the establishment of the metallogenic model have been made. 1 through systematic analysis of the zircon U-Pb age of the actash volcanic rocks, Salo Bea Lvome and gigzananite, the systematic analysis of the age of zircon has been obtained. The northern slope of the Kun GI mountain, Kunlun, was originally divided into Carboniferous volcanic rocks. The age of the formation age should be the early two fold and Late Permian. The age of the actash volcanic rocks is 284.6Ma, the age of the zorai basalt is 263.0Ma, and the age of the igzanite is 263.8Ma.2 actash volcanic rocks at the beginning of the island arc expansion. The Shuangfeng type volcanic rocks and calc alkaline basalts with the nature of island arc pulls. The gezananite and soli basalt are relatively late N-MORB island arc basalts and island arc andesite. The age of the two diagenesis is nearly the same. Thus, it is presumed that the gzananite may be the same volcanic rock with the saluyi basalt. The rock geochemical characteristics of the Saloy basalt - gzananite reflect that the tectonic environment produced by the volcanic rocks is in the transitional stage between the island arc to the inter arc (post arc) basin and the rock geochemical characteristics of the alktash ore bearing surrounding rock through the study of the rock geochemistry of the alktash ore bearing rocks in the ore bearing rock. It is believed that the ore bearing surrounding rock of the actash deposit can be used in.3. The ore hosting rocks of the massive sulfide deposits produced in the Okinawa island arc of the Western Pacific Ocean are compared. The ore bearing surrounding rock of the saoli copper deposit is a occipital basalt, which is similar to the surrounding rock of the Cyprus type deposit by.4 to the detailed geochemical (ore earth) of the alktower copper gold deposit and the saoli copper deposit. The study of chemistry, surrounding rock geochemistry, S isotopes), all evidences show that the metallogenic material of Aktas copper gold deposit is mainly derived from volcanic rocks. The metallogenic material of the deposit is derived from the volcanic and marine sediments.5 through the analysis of the main trace elements of sulfide in the Aktas and the sulphoxide copper deposits, from the footwall to the footwall. The upper plate has obvious zoning laws. According to this, the mineralization process of the Aktas deposit and the zexo copper deposit is divided into three stages respectively. The mineralization process of the Aktas copper gold deposit is the "stage" of the volcano jet, the "stage" of the volcanic hydrothermal deposition, the "stage" of the ore bearing hot brine + volcanic hydrothermal deposition, and the zore deposit copper deposit. The metallogenic process is the "stage" of rich ore hot brine deposit, hot brine deposit + volcanic hydrothermal sedimentation "stage". The sulfur of the.6 Anke deposit in the "stage" of the ore bearing hot brine deposit is mainly derived from the magmatic jet, the sulphur deposit is a polysulfide source, the sulfur may be the sea water sulfur, the volcanic jet sulfur and the sedimentary sulfur are mixed with the same precipitation. The formation age of the accumulated massive sulfide deposits coincides with the age of the formation of volcanic rocks. Therefore, the age of the actag copper gold deposit is early Permian, and the age of the Re-Os isotope age of the pyrite in the Late Permian.8 acash copper gold deposit is different from that of the surrounding rock age. The Re-Os system of pyrite may not meet the homology condition, but it is reserved for the Re-Os age of pyrite. It is possible that the east mining area of the OAC deposit is the remnants of the Codi oate ophiolite suite. The contact relationship between the eastern mining area and the strata of the eastern mining area needs to be further studied by the.9 and the typical Sophie deposit. The types of massive sulfide deposits are compared. All of the two are typical VMS deposits associated with volcanic activity. The genetic types of the deposits are the Shuangfeng type volcanic rocks of the late Paleozoic in the extended island arc environment, the basic volcanic rocks and the overlying subsidence in the.10 West Kunlun region of the sub type massive sulfide deposits and the Cyprus type massive sulfide deposits, respectively. The strongly altered strata formed by the contact of the lithofacies are the key layers of the VMS deposit in the West Kunlun, and the iron cap and jarosite belt are often formed on the surface.
【学位授予单位】：中国科学院研究生院(广州地球化学研究所)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P588.14;P612
，

本文编号：2025779