攀西地区含矿基性—超基性岩岩石地球化学特征及成矿作用分析

发布时间：2018-04-17 01:31

本文选题：基性-超基性岩 + 岩石地球化学　；参考：《成都理工大学》2015年硕士论文

【摘要】：攀西地区基性-超基性岩是峨眉火成岩省的组成部分之一,本次研究主要对攀西地区的白马矿区、红格矿区和攀枝花矿区三个含矿基性-超基性岩体进行岩石地球化学对比分析,总结基性-超基性岩岩石地球化学特征,对比分析三个矿区的相关性,初步取得以下几方面的认识:(1)根据岩体和构造的关系,将攀西地区基性-超基性岩体分为两个主要的亚带,其中属于安宁河亚带的基性-超基性含矿岩体主要分布于安宁河亚带附近,北起太和矿体,向南经白马岩体至红格岩体,以层状基性-超基性岩为主;攀枝花亚带的基性-超基性岩体主要分布在攀枝花断裂带的东面,以大-小型层状基性-超基性岩体为主,岩体内钒钛磁铁矿呈似层状产出,层位稳定。(2)攀西地区岩体韵律层理及岩相旋回发育,其中韵律是固化面推进与岩浆化学扩散耦合的结果,而岩相旋回则表现为岩相组合的规律性重复,总体而言从上至下基性程度逐渐升高,而韵律旋回特征表明攀西地区岩浆多期次的特征,成矿的主要基性,超基性岩体基本都处于旋回的中下部。(3)从韵律特征分析可以看出:攀西地区主要造岩矿物的色率、含量和化学成分等在垂向上更替叠置形成交替的条带互层,岩体从上至下色率大致从浅变暗,岩体整体可分为若干个韵律层,而且每个大的韵律层里还含有小的韵律层,并且大小韵律层的色率都是从上至下色率逐渐变深。(4)通过分析攀西地区红格矿区、白马矿区和攀枝花矿区岩石地球化学特征得出:三个矿区基性-超基性岩都属于高钾拉斑玄武岩系列,氧化物和MgO的相关图解上可以看出氧化物一直参与岩浆的分异结晶过程,而从稀土元素球粒陨石标准化分布型式图上分析发现攀枝花矿区、白马矿区具有明显的Eu正异常,而红格矿区Eu异常不明显,从微量元素原始地幔标准化蛛网图上,可以看出三个矿区的岩石样品都出现亏损高场强元素Zr的特征。(5)通过总结前人的年龄数据,得出攀西地区基性-超基性岩体的形成时代和峨眉山玄武岩的主喷发时期是一致的,大约为260±2Ma。表明峨眉山玄武岩与攀西基性-超基性岩体应该为岩浆演化过程中同源异相的产物。
[Abstract]:The basic-ultrabasic rock in Panxi area is one of the components of Emei igneous province.Three ore-bearing basic-ultrabasic rock bodies in Hongge and Panzhihua mining areas were compared and analyzed, and the petrogeochemical characteristics of basic-ultrabasic rocks were summarized, and the correlation of the three ore areas was compared and analyzed.According to the relationship between rock mass and structure, the basic-ultrabasic rock body in Panxi area is divided into two main subzones.The basic-ultrabasic ore-bearing rock bodies belonging to the Anning River subzone are mainly distributed near the Anning River subzone, starting from the Taihe orebody in the north, running south through the Baima rock body to the Hongge rock body, and mainly stratiform basic-ultrabasic rock.The basic-ultrabasic rock bodies in the Panzhihua subzone are mainly distributed in the east of the Panzhihua fault zone, dominated by the large and small layered basic-ultrabasic rocks, and the vanadium titanomagnetite in the rock body is bedded.The rhythmic bedding and lithofacies cycle of rock mass in Panxi area are characterized by the coupling of solidified surface propulsion and magmatic chemical diffusion, while the lithofacies cycle is characterized by the repeated regularity of lithofacies assemblage.In general, the degree of basicity gradually increased from top to bottom, while the rhythmic cycle characteristics indicated that the magma in Panxi area was characterized by multi-stage magma and the main metallogenic elements.From the analysis of rhythmic characteristics, it can be seen that the color rate, content and chemical composition of the major rock-forming minerals in Panxi area are superimposed vertically to form alternate banded interbeds.From top to bottom, the color rate of rock mass changes from shallow to dark, and the whole rock mass can be divided into several rhythmic layers, and each of the large rhythmic layers also contains small rhythmic layers.And the color rate of the large and small prosodic layers is gradually becoming deeper from top to bottom.) through the analysis of Hongge mining area in Panxi area,The petrogeochemical characteristics of Baima and Panzhihua mining areas show that the basic-ultrabasic rocks belong to the high-potassium tholeiite series. The related diagrams of oxides and MgO show that oxides have been involved in the differentiation and crystallization of magma.From the analysis of the standardized distribution pattern of chondrites of rare earth elements, it is found that in Panzhihua mining area, the Baima ore area has obvious positive EU anomaly, while the EU anomaly in Hongge mine is not obvious.It can be seen that the characteristics of depleted high field strength element Zr in rock samples in the three mining areas are consistent with the main eruption period of Emeishan basalt by summarizing the previous age data and drawing the conclusion that the age of the basaltic body in Panxi area is the same as that of the Emeishan basalt.About 260 卤2 Ma.It is suggested that Emeishan basalt and Panxi basalt-ultrabasic rock body should be the product of homologous facies during magmatic evolution.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P588.12;P611

【参考文献】