内蒙古林西水头萤石成矿带不同矿段地质地球化学特征对比研究  

COMPARATIVE STUDY ON GEOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF DIFFERENT MINE SECTIONS OF SHUITOU FLUORITE METALLOGENIC BELT IN LINXI AREA,INNER MONGOLIA

作　　者：王启博 张寿庭[1] 唐利[1] 王亮[1] 郭俊 张彦生 尹少波 Wang Qibo;Zhang Shouting;Tang Li;Wang Liang;Guo Jun;Zhang Yansheng;Yin Shaobo(School of Earth Sciences and Resources,China University of Geosciences,Beijing 1000S3,China;Inner Mongolia Nonferrous Geological Mining(Group)108 Co.Ltd,Chifeng 024000,China;Huai Mine West Mine Investment Management Co.Ltd,Ordos 017000,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]内蒙古有色地质矿业(集团)一○八有限责任公司,内蒙古赤峰024000 [3]淮矿西部煤矿投资管理有限责任公司,内蒙古鄂尔多斯017000

出　　处：《矿物岩石》2022年第2期81-93,共13页Mineralogy and Petrology

基　　金：国家自然科学基金项目(批准号:41902193);中央高校基本科研业务费项目(编号:2652019191,2652019047)。

摘　　要：水头萤石成矿带位于内蒙古林西地区北部,矿体主要赋存于二叠系火山—沉积岩中,并严格受近SN向、NNE向断裂构造控制。本次研究基于野外地质调查、矿床地质特征、萤石稀土元素及流体包裹体综合研究,结合前人研究成果和探矿工程揭露情况,探讨带内成矿差异性的控制因素。研究区萤石和石英的ΣREE含量分别为5.84×10^(-6)~198.38×10^(-6)和0.71×10^(-6)~4.74×10^(-6),ΣLREE/ΣHREE平均值分别为1.43和4.32,均呈现弱的Eu正异常和Ce负异常,指示三个矿床具有相似的成矿环境和物质来源,且三个矿床的成矿流体的运移距离从南到北逐渐增大。研究区萤石的流体包裹体以气液两相为主,均一温度集中于140~240℃,盐度集中于0.4%~3.4%NaCl_(eqv),密度集中于0.86~0.93 g/cm^(3),从南到北三个矿床的成矿温度逐渐降低,成矿流体的盐度和密度逐渐下降。成矿带内矿体特征差异的控制因素包括控矿断裂的性质、成矿流体演化过程和后期构造活动对萤石矿体的影响。区内萤石矿床可能与金属矿床具有密切的成因联系,代表岩浆热液成矿系统的远端产物。The ore bodies of Shuitou fluorite metallogenic belt located in the northern Linxi area of Inner Mongolia mainly occur in the Permian volcanic-sedimentary rocks and are strictly controlled by the nearly S-N trending and NNE-trending faults.Based on geological field investigation,geological characteristics of the deposit,comprehensive study of fluorite rare earth elements and fluid inclusion,combined with previous studies and engineering exploration projects,this paper discusses the controlling factors of metallogenic difference of the three deposits in the belt.Geochemical analysis indicates that the σREE content of fluorite and quartz in the study area is 5.84×10^(-6)-198.38×10^(-6) and 0.71×10^(-6)-4.74×10^(-6),respectively.The average value of ΣLREE/ΣHREE is 1.43 and 4.32,respectively,with weak positive Eu anomaly and negative Ce anomaly.The three fluorite deposits have a similar metallogenic environment and material sources,and the migration distance of ore-forming fluid increases gradually from south to north.The analysis of gas-liquid phase fluid inclusions in fluorite in the study area shows that the homogenization temperature is 140-240℃,the salinity is 0.4%-3.4% NaCl_(eqv),and the density is 0.86 g/cm^(3)-0.93 g/cm^(3).It reveals that the ore-forming temperature of the three deposits decreases gradually from south to north,and the salinity and density of ore-forming fluid decrease gradually.The controlling factors for the differences of orebody characteristics in the metallogenic belt include the nature of ore-controlling faults,the evolution of ore-forming fluid and the influence of late tectonic activities on fluorite orebodies.It is considered that the fluorite deposits in the area are likely to be related to the formation of metal deposits and represent the distal products of the magmatic-hydrothermal metallogenic system.

关 键 词：萤石 成矿地质特征 稀土元素 水头萤石成矿带 内蒙古林西 

分 类 号：P579[天文地球—矿物学]