内蒙古维拉斯托矿床隐爆角砾岩型锂铷矿体的成矿流体特征与成矿过程
Fluid Characteristics and Mineralization Process of Cryptoexplosive Breccia-Type Li-Rb Ore Body in Weilasituo Deposit,Inner Mongolia
王雨婷 1杜静国 1雷如雄 1邓小华 1吴昌志2
作者信息
- 1. 长安大学地球科学与资源学院,陕西西安 710054
- 2. 长安大学地球科学与资源学院,陕西西安 710054;新疆自然资源与生态环境研究中心,新疆乌鲁木齐 830000
- 折叠
摘要
维拉斯托矿床同时发育碱长花岗岩型锡铷矿体、隐爆角砾岩型锂铷矿体和石英脉型锡矿体,其中隐爆角砾岩型矿体位于另外两类矿体之间,是理解该矿床成矿过程和成因的关键.以隐爆角砾型矿体中石英晶体及其中的流体包裹体为主要研究对象,通过石英阴极发光、流体包裹体显微测温、激光拉曼和原位氧同位素等测试手段,探索流体演化与锂铷矿化的关系.研究结果表明,隐爆角砾岩中的石英晶体生长经历了3个阶段(Q1、Q2和Q3).从Q1到Q2,包裹体盐度相似、均一温度降低、石英氧同位素变轻,指示大气降水加入增多.综合前人与本次研究成果,认为维拉斯托隐爆角砾岩型矿石是岩体顶部隐爆作用的产物,减压的岩浆热液在上升过程中与大气降水发生了不同程度的混合,造成了其中富锂云母的沉淀和锂铷的矿化.
Abstract
Three main types of ore bdies are well developed in the Weilasituo deposit,including alkaline granite type Sn-Rb ore body,cryptoexplosive breccia-type Li-Rb ore body,and quartz vein type Sn ore body.The cryptoexplosive breccia-type ore body was located between the other two types of ore bodies and was assumed as the key point to understand the process and genesis of the cryptoexplosive breccia-type ore body.This contribution mainly focuses on quartz crystals and fluid inclusions therein from the cryptoexplosive breccia-type ore body.Through quartz cathodoluminescence imaging,fluid inclusion microthermometry,laser Raman spectroscopy,and in situ oxygen isotope analysis,it tries to address the relationship between fluid evolution and Li-Rb mineralization.Three stages(Q1,Q2,and Q3)of crystallization have been identified based on quartz CL imaging,while Q1 and Q2 are well-developed and closely related to Li-Rb mineralization.Fluid inclusions in Q2 exhibit similar salinity but lower homogeneous temperatures than those in Q1.The oxygen isotope composition of Q2 is lighter than that of Q1.Combined with previous and our study results,it is assumed that the cryptoexplosive breccia-type mineralization of Weilasituo should be formed by cryptoexplosion of volatile which converges on the top of mineralized porphyry,and the mixing of magmatic-hydrothermal fluid and meteoric water might control the precipitation process of zinnwaldite,and eventually form the cryptoexplosive breccia-type Li-Rb mineralization of Weilasituo.
关键词
流体包裹体/石英氧同位素/隐爆角砾岩/锂矿/维拉斯托/岩石学/矿床学Key words
fluid inclusion/quartz oxygen isotope/cryptoexplosive breccia/lithium deposit/Weilasituo/petrology/mineral deposits引用本文复制引用
出版年
2024
NETL
NSTL
万方数据