摘要
复兴屯矿床是近年来在内蒙古自治区科尔沁右翼前旗地区的勘探找矿工作中发现的大型银铅锌多金属矿床。鉴于该矿床的研究非常薄弱,开展其成矿元素赋存特征、沉淀机制及矿床成因类型等问题的研究可为该矿床的成因研究提供理论依据。以复兴屯银铅锌多金属矿床不同阶段形成的闪锌矿为研究对象,开展了矿相学、矿物主量元素和微量元素组成的研究,探讨了成矿元素的沉淀机制和矿床的成因类型。结合野外调查和室内矿相学观察,将复兴屯矿床的成矿过程划分为3个成矿阶段:铜锌硫化物阶段(Ⅰ阶段)、铅锌硫化物阶段(Ⅱ阶段)、银锌硫化物阶段(Ⅲ阶段)。电子探针分析结果表明,闪锌矿中Fe含量变化较大,Fe含量与Zn含量呈明显负相关关系。LA-ICP-MS分析结果表明,由Ⅰ阶段到Ⅲ阶段,闪锌矿中Fe,Mn,In含量逐渐降低,Ga,Ge,Sb含量略有增加。结合激光剥蚀曲线与元素间相关性图解,元素Fe,Mn,Cd,Cu,In和Ag以类质同象形式赋存于闪锌矿之中;Pb以显微包裹体形式存在,而Bi和Sb主要赋存于闪锌矿的方铅矿显微包裹体中。闪锌矿的微量元素组成还表明,成矿过程中周期性的压力波动导致了闪锌矿中韵律环带的形成,成矿流体的多次减压和降温是复兴屯矿床主要的矿质沉淀机制。综合矿床地质特征和闪锌矿微量元素特征,我们认为复兴屯矿床为中硫化型浅成低温热液矿床。
[Objective]The Fuxingtun deposit is a recently discovered large Ag-Pb-Zn polymetallic deposit in Horqin Right Wing Front area,Inner Mongolia.However,the researches on the deposit are very scarce.The study investigates occurrence characteristics of ore-forming elements,precipitation mechanism and genetic type of the deposit,in order to provide theoretical basis for the genesis of the deposit.[Methods]This study focused on sphalerite in different stages of the Fuxingtun Ag-Pb-Zn polymetallic deposit,and obtained metallography,major and trace elemental compositions of sphalerite,in order to discuss the precipitation mechanism of ore-forming elements and the genetic types of this deposit.[Results]Combined with field investigation and metallography observations,the metallogenic process of the Fuxingtun deposit can be divided into three stages:Cu-Zn sulfide stage(StageⅠ),Pb-Zn sulfide stage(StageⅡ)and Pb-Zn sulfide stage(StageⅢ).The results of electron probe microanalysis show that the content of Fe in sphalerite varies greatly,and there is an obvious negative correlation between Fe and Zn.The results of LA-ICP-MS analysis showed that,the contents of Fe,Mn and In in sphalerite decreased gradually from Stage I to III,whereas those of Ga,Ge and Sb increased slightly.Based on the diagrams of laser ablation signal curve and the correlation among different elements,this study constrained that Fe,Mn,Cd,Cu In,and Ag in sphalerite are present as the form of isomorphism.On the other hand,Pb exists in the form of micro-inclusions,while Bi and Sb mainly occur as galena micro-inclusions in sphalerite.The trace element compositions of sphalerite grains also show that the periodic pressure fluctuation in the ore-forming process is responsible for the formation of oscillatory zone in sphalerite.We proposed that the multiple decompression and cooling of ore-forming fluids are the main mechanism of mineral precipitation in the Fuxingtun deposit.[Conclusion]Combined with the geological characteristics of the deposit and the trace
作者
张青
张成
段海龙
徐宏国
张欣
Zhang Qing;Zhang Cheng;Duan Hailong;Xu Hongguo;Zhang Xin(Geological Survey Institute of Inner Mongolia,Hohhot 010020,China;Inner Mongolia Key Laboratory of Magmatic Mineralization and Ore-Prospecting,Hohhot 010020,China;Land&Resource Exploration Development Company Limited of Inner Mongolia,Hohhot 010020,China)
出处
《地质科技通报》
CAS
CSCD
北大核心
2023年第5期161-174,共14页
Bulletin of Geological Science and Technology
关键词
复兴屯银铅锌多金属矿
闪锌矿
矿物化学
矿床成因
Fuxingtun Ag-Pb-Zn polymetallic deposit
sphalerite
mineral chemistry
deposit genesis
