胶东西北部栾家河型中粗粒等粒二长花岗岩构造岩相特征研究

发布时间：2018-02-03 00:37

本文关键词： 花岗岩构造栾家河型花岗岩郭家店岩体断裂蚀变花岗岩捕掳体应变　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：栾家河型花岗岩是胶东玲珑杂岩体重要组成部分,由于与胶东大规模金矿化关系密切,前人对胶东地区的花岗岩做了大量的研究,认为胶东地区与金矿有成相关的花岗岩根据其形成的构造应力场的明显差别可分为三个主要类型:玲珑-昆嵛山型似片麻状中粗粒黑云母花岗岩,栾家河型-伟德山型粗粒等粒二长花岗岩,郭家岭型似斑状花岗闪长岩。而栾家河-伟德山型花岗岩在胶东西北部又主要划分为栾家河岩体,郭家店岩体和毕郭岩体。本论文依托项目《胶西北金矿深部找矿地球化学方法集成与示范》与《玲珑矿田东部断裂蚀变成矿体系三维研究与深部预测》选取胶东西北部栾家河型花岗岩作为研究对象对其进行构造岩相填图;对岩体内捕掳体以及矿物颗粒进行应变分析;依据成岩构造性质进行花岗岩构造的分类;分析不同断裂构造蚀变花岗岩带中构造差应力与应变的关系。得出了以下结论:1、对栾家河岩体中捕掳体进行测量得到多组捕掳体形态轴比,其平均最终形态轴比Rf范围为2.1~2.6,,采用捕掳体对数形态图解法,得到其平均原始形态轴比Ri=1.73,平均应变比为Rs=1.35。花岗岩体内捕掳体没有出现明显变形,岩石侵位过程中,处于较均压的状态。2、栾家河型等粒二长花岗岩具有典型的花岗结构。长石的交代蚀变现象均不发育。岩石无定向构造,即使是晚期形成的石英,也没有像玲珑花岗岩与郭家岭花岗闪长岩两类岩石中那样呈塑性拉长状,而是较稳定且没有很强的定向外力环境中的产物。这是张裂区带岩相的特色。3、统计郭家店岩体中石英矿物颗粒的变形轴比,其最大变形轴比范围为1.3~1.4,几乎没有变形构造,区域上也无明显应变规律,具有引张相特色。4、对焦家金矿断裂构造蚀变岩分带,通过石英位错密度法测定了不同蚀变带中岩石差应力值,差应力值最大出现在强钾化花岗岩带,由韧性变形到脆性变形过程中差应力值变小,黄铁绢英岩带因岩石破碎造成应力释放而低于强钾化带。
[Abstract]:Luanjiahe granite is an important part of Linglong complex in Jiaodong. Because of its close relationship with large-scale gold mineralization in Jiaodong, the previous people have done a lot of research on granites in Jiaodong area. It is considered that the granites related to gold deposits in Jiaodong area can be divided into three main types according to the obvious difference of tectonic stress field formed by them: Linglong Kunyu granitoid granitoids. Luanjiahe-Weideshan type isomorphic isomorphic granite, Guojialing type like porphyry granodiorite, and Luanjiahe-Weideshan granite are mainly divided into Luanjiahe pluton in the northwest of Jiaodong. Guojiadian and Biguo rock bodies. Based on the project "Integration and demonstration of geochemical methods for deep ore-prospecting in Jiao northwest gold deposit" and "Three-dimensional study and deep prediction of fracture erosion system in eastern Linglong ore field", this paper selects Jiaodong. Luanjiahe granitic granites in the northwest of China are used as the research objects to map the tectonic facies of the granites. The strain analysis of the trapped bodies and mineral particles in the rocks is carried out. Classification of granitic structures according to diagenetic tectonic properties; The relationship between tectonic differential stress and strain in the altered granite belt of different fault structures is analyzed. The following conclusions are drawn: 1. By measuring the captivates in Luan Jiahe rock mass, the shape and axial ratio of several groups of captivates are obtained. The average final shape axis ratio (RF) is 2.1 ~ 2.6m. The average original shape axis ratio (Ri=1.73) is obtained by using the logarithmic morphological diagram method. The average strain ratio is RsN 1.35. There is no obvious deformation of the captivity in the granite, and the rock emplacement is in a relatively homogeneous state of .2. Luanjiahe isomorphic monzogranite has a typical granitic structure. The metasomatic alteration of feldspar is not developed. The rock has no directional structure, even the quartz formed in the late period. It is not as plastic elongated as in Linglong granodiorite and Guojialing granodiorite, but is relatively stable and not produced in a strong directional external force environment, which is the characteristic of lithofacies of the Zhangjialing belt. The maximum deformation axial ratio of quartz mineral particles in the Guojiadian rock mass is 1.31.4.There is almost no deformation structure, and there is no obvious strain law in the region. The differential stress values of rocks in different altered zones were measured by quartz dislocation density method in Jiaojia gold deposit, and the maximum difference stress value appeared in the strong potash granite zone. In the process of ductile deformation to brittle deformation, the value of differential stress becomes smaller, and the stress release of the Huangtianshinite belt is lower than that of the strong potash zone because of the stress release caused by rock breakage.
【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】：2017
【分类号】：P618.51

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