江西永平—石塘推覆构造及龙头岗矿区控矿构造分析

发布时间：2018-06-02 18:46

本文选题：永平—石塘 + 推覆构造　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：永平—石塘推覆构造及龙头岗矿区位于华夏板块西北缘的北武夷成矿带,中侏罗世以来由于东亚岩石圈大规模的板块运动,导致该成矿带强烈的构造变形和岩浆作用。本论文是在野外地质调研、系统地收集和整理前人研究成果的基础上,对成矿地质构造背景、矿床地质特征等进行综合研究,总结构造控矿规律和矿床成因。取得的主要成果和结论如下：1、永平一石塘推覆构造是由于燕山期时伊佐奈崎板块向欧亚板块俯冲、挤压形成,受控于中元古界滹沱系至新元古界震旦系上统组成的的中侏罗世推覆体,推到下侏罗统水北组地层之上,推覆方向为来自南东向,推覆时代大致从175-150 Ma。外来岩系变形强烈,原地岩系主要表现为褶皱发育。2、龙头岗矿区位于永平—石塘推覆体内部,矿体形态主要受由于中生代推覆构造而形成的倒转褶皱中的层间滑脱构造控制,热液通过由NW向挤压应力场下产生的共轭剪切断裂F2和F4为热液提供侵位的通道,后期形成的断裂F3及持续发育的推覆构造对矿体有一定改造作用。3、龙头岗矿区发育的岩浆岩主要为花岗斑岩、二长花岗斑岩和黑云母二长花岗斑岩。通过LA-ICP-MS锆石U-Pb法对二长花岗斑岩、黑云母二长花岗斑岩进行测年,获得这2种岩浆岩的年龄分别为153.9±1.4Ma (MSWD=4.1)、151.3±1.4Ma (MSWD=2.2)成矿时代为晚侏罗世和早白垩世。4、根据龙头岗矿区构造变形、矿床特征,及其与赣东北地区中侏罗世以来构造背景及典型铜多金属矿床成矿时代对比建立,认为在区域推覆构造特别发育的地方,当满足上覆老地层之下含有C20赋矿岩层,且有花岗岩岩体存在时,在该区有可能蕴藏有铜多金属矿床,有待开展进一步工作。龙头岗矿床即为受中侏罗世以来(170-150 Ma)推覆构造控制并与同时期岩浆侵入活动有关的浅部矽卡岩型—深部斑岩型铜多金属矿床。
[Abstract]:Yongping-Shitang nappe tectonics and the northern Wuyi metallogenic belt located in the northwestern margin of the Huaxia plate in the Longtougang mining area. Since the Middle Jurassic, the tectonic deformation and magmatism of the metallogenic belt have been strong due to the large-scale plate movement in the lithosphere of East Asia. On the basis of field geological investigation and systematic collection and collation of previous research results, this paper comprehensively studies the geological background and geological characteristics of ore-forming structures, and summarizes the rules of tectonic ore-controlling and the genesis of ore deposits. The main achievements and conclusions obtained are as follows: 1. The Yitang nappe structure in Yongping was formed by the Yanshanizaki plate subducting into the Eurasian plate during the Yanshanian period. The Middle Jurassic nappe, controlled by the Middle Proterozoic Hutuo system to the Neoproterozoic Sinian Upper Series, was pushed above the formation of the Lower Jurassic Shuibei formation. The direction of the nappe is from the south to the east, and the nappe age ranges from 175-150 Ma. The deformation of the extraneous rock series is strong, the in-situ rock series is mainly characterized by fold development, the Longtougang mining area is located in the Yongping-Shitang nappe body, and the orebody shape is mainly controlled by the interlayer slip structure in the inverted fold formed by the Mesozoic nappe structure. Hydrothermal solution provides an emplacement channel for hydrothermal solution through conjugate shear fracture F2 and F4 produced by NW extrusion stress field. The fault F3 formed in the late stage and the continuously developing nappe structure have a certain remaking effect on the orebody. The magmatic rocks developed in the Longtougang mine area are mainly granitic porphyry, Erchang granitic porphyry and biotite monzagonal granitic porphyry. The dating of Erchang granitic porphyry and biotite granitic porphyry is studied by LA-ICP-MS zircon U-Pb method. The age of these two magmatic rocks is 153.9 卤1.4Ma / 4.1mwdf. 151.3 卤1.4Ma / MSWD2.2respectively) the metallogenic ages are late Jurassic and early Cretaceous .4. according to the tectonic deformation of the Doutougang mine, the age of the two magmatic rocks is 153.9 卤1.4Ma. The characteristics of the deposits, and their correlation with the tectonic setting since the Middle Jurassic and the metallogenic ages of typical copper polymetallic deposits in northeast Jiangxi, suggest that where the regional nappe structures are particularly developed, there are C20 ore-bearing strata below the overlying old strata. When granitic rock mass exists, copper polymetallic deposit may exist in this area, which needs further work. The Longtougang deposit is a shallow skarn-deep porphyry copper polymetallic deposit controlled by the nappe structure since the Middle Jurassic and related to the magmatic intrusion of the same period.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P613

【参考文献】