
内蒙古固阳地区石炭纪花岗岩类岩石学特征研究.pdf
62页密级: 石家庄经济学院硕士学位论文 内蒙古固阳地区石炭纪花岗岩类岩石学特征研内蒙古固阳地区石炭纪花岗岩类岩石学特征研 究究 论 文 作 者: 武兴龙 学 生 类 别: 全日制 一 级 学 科: 地质学 学 科 专 业: 矿物学、岩石学、矿床学 指 导 教 师: 王立峰 职 称: 教授 Secrecy Rate:: Dissertation Submitted to Shijiazhuang University of Economics for The Master Degree of Mineralogy, Petrology, Mineral deposit geology Study on the petrology characteristics of the Carboniferous granite in GuYang area,,Inner Mongolia by WU XINGLONG Supervisor: WANG LIFENG June 2015 原创性声明原创性声明 本人郑重声明:所呈交的学位论文,是本人在导师指导下,进行研究工作所取得的成果。
除文中已经注明引用的内容外,本学位论文不包含任何他人或集体已经发表的作品内容,也不包含本人为获得其他学位而使用过的材料对本论文所涉及的研究工作做出贡献的其他个人或集体,均已在文中以明确方式标明本学位论文原创性声明的法律责任由本人承担 学位论文作者签名: 日期: 关关于学位论文版权使用授权的说明于学位论文版权使用授权的说明 本人完全了解石家庄经济学院关于收集、保存、使用学位论文的以下规定:学校有权采用影印、缩印、扫描、数字化或其它手段保存论文;学校有权提供本学位论文全文或者部分内容的阅览服务;学校有权将学位论文的全部或部分内容编入有关数据库进行检索、交流;学校有权向国家有关部门或者机构送交论文的复印件和电子版 (保密的学位论文在解密后适用本授权说明) 学位论文作者签名: 日期: 导师签名 : 日 期 :I 摘摘 要要 内蒙古固阳地区位于华北板块北缘中段,索伦缝合线和集宁—隆化断裂以南一般认为,古亚洲洋板块向华北板块的俯冲时间为古生代时期,对本区石炭纪花岗岩类岩石的岩石学特征、岩石成因以及构造背景的研究,对更好的认识石炭纪花岗岩类乃至整个古生代的花岗岩类以及整个华北板块的构造演化有重要的理论意义。
本论文依托于内蒙古自治区大老虎店等四幅 1:5 万区域地质矿产调查,在基于前人研究成果的基础上,通过对固阳地区石炭纪花岗岩类的分布、产出规模、以及岩石学特征的研究,利用固阳地区花岗岩类的主量元素、微量元素以及稀土元素并结合花岗岩新的理论研究成果,对固阳地区石炭纪花岗岩类的形成原因及构造背景进行了进一步的探讨,主要得到了以下认识: (1)固阳地区石炭纪花岗岩类在岩性上主要有三种,分别是黑云母花岗闪长岩、石英二长岩和黑云母正长花岗岩,本文主要对黑云母花岗闪长岩和石英二长岩进行了研究, 通过对其地球化学元素特征的分析, 两者均为准铝质高钾钙碱性 I 型花岗岩类 (2)黑云母花岗闪长岩和石英二长岩均具有较高的结晶分异指数(DI),说明其岩浆在演化过程中经历了较好的结晶分异作用 (3)从微量元素和稀土元素含量特征来看,两者均具有高 Sr、低 Yb、轻重稀土高度分馏的特点, 再结合其具有较高的 Al2O3(大于等于 15%)及较小的 MgO(小于等于3%)等主量元素的特点,笔者认为固阳地区石炭纪花岗岩类为与典型埃达克岩具有相似地球化学特征的埃达克质岩 (4)通过对固阳地区石炭纪花岗岩类的形成原因和构造背景的分析可知,该地区石炭纪花岗岩类在成因上为古亚洲洋板块向华北板块俯冲作用下形成的壳幔混合型幔源岩浆熔融而成;在构造背景上,黑云母花岗闪长岩形成于板块消减过程的大陆弧环境,石英二长岩形成于板块俯冲作用的晚造山期环境。
关键词:花岗岩类;岩石学特征;构造背景;固阳地区 II III Abstract Guyang region, Inner Mongolia is located in the middle part of the northern margin of north china plate, which is on the south of the Solonker suture line and the Jining—Longhua fault. It is generally recognized that the paleo asian ocean plate subducted to the north china plate on paleozoic. Study on the petrological characteristics, petrogenesis and tectonic setting of the carboniferous granite of this area carry major implications for understanding the granite and the tectonic evolution of the north china plate. Supported on 1:50000 survey of mineral resources in the four maps of Dalaohudian, Inner Mongolia, this paper analyzed on the rock geochemical data through the study on the distribution and the scale of production of carboniferous granite and the petrological characteristics on the basis of the previous research results, found out the distribution characteristics of major elements, trace elements and rare earth elements. By combining with the relevant theory research, there is a further discuss on the cause of formation and tectonic background of the carboniferous granitoids in Guyang area, and we have obtained the following understandings: (1)There are three carboniferous granite on Guyang area respectively are adamellite, biotite granodiorite and biotite syenogranite. This paper mainly studies the adamellite and the biotite granodiorite. Through the analysis of the characteristics of chemical elements, both of them are quasi aluminous, high K, calc alkaline I type granite. (2)Two kinds of rocks both have the higher crystallization differentiation index, illustrate that magma experienced better crystallization differentiation in the process of evolution. (3)From the characteristics of trace elements and rare earth elements, they both have high Sr, low Yb, highly fractionated REE, higher Al2O3 and the smaller MgO, conclude that Guyang carboniferous granite are adakitic rocks. (4)Through the analysis of the formation and tectonic background of the carboniferous granitoids in Guyang area, we can know that carboniferous granite of this area are melting by mantle derived magma which formed by the paleo asian ocean plate subducted to the north china plate; In the tectonic background, biotite granodiorite rocks formed in continental arc environment and the adamellite formed in late orogenic period. Keywords: granitoid; petrological characteristics; tectonic background; Guyang area IV V 目目 录录 摘 要 ..............................................................................................................................................I Abstract ......................................................................................................................................... III 第一章 绪论.................................................................................................................................. 1 1.1 选题依据 ................................................................................................................................ 1 1.2 研究的主要内容及技术路线 ............................................................................................ 1 1.2.1 研究的主要内容 ..........................................................................................。
