云南都龙锡锌多金属矿床成矿阶段与成矿流体  

Mineralization Stages and Ore-Forming Fluid of Dulong Sn-Zn Polymetal Ore Deposit, Yunnan Province, China

作　　者：叶霖[1] 鲍谈[1,2] 刘玉平[1] 张乾[1] 王小娟[1,2] 何芳[1,2] 王大鹏[1] 蓝江波[1] 

机构地区：[1]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵州贵阳550002 [2]中国科学院大学,北京100039

出　　处：《矿物学报》2016年第4期503-509,共7页Acta Mineralogica Sinica

基　　金：云南华联锌铟股份有限公司委托项目(KY20120910);中国科学院地球化学研究所"十二五"项目群(SKLODG-ZY125-02;SKLODG-ZY125-04);国家自然科学基金(批准号:41173063)

摘　　要：云南马关都龙锡锌多金属矿床位于滇东南老君山锡锌钨多金属成矿区南部,是我国三大锡石硫化物矿床之一,其地质及成矿作用复杂,矿物种类繁多。本文根据矿床中矿物共生组合特征,从早到晚划分出以下4个阶段:(a)夕卡岩阶段,早期为无水夕卡岩阶段,形成矿物以石榴石和透辉石为主,晚期为含水夕卡岩阶段,形成矿物以阳起石、绿帘石、绿泥石和符山石等为主;(b)氧化物阶段,磁铁矿、锡石和白钨矿等氧化物在此阶段大量沉淀;(c)硫化物阶段,早期形成磁黄铁矿→黄铁矿→黄铜矿、辉钼矿,晚期形成闪锌矿(黄铜矿)和少量方铅矿组合;(d)碳酸盐阶段(方铅矿及少量闪锌矿),其成矿元素与夕卡岩蚀变类型的垂直分带特征与典型夕卡岩型矿床较类似,矿化类型和围岩蚀变的分带与隐伏岩体距离有关,该矿床属于与燕山晚期花岗岩有关的岩浆热液夕卡岩型多金属矿床。流体包裹体研究结果表明,从成矿早阶段到晚阶段,成矿流体从中高温较高盐度逐渐演化为中低温低盐度流体,压力的降低和大气降水的混入造成的流体沸腾可能是Sn和Zn等成矿元素大量沉淀的主要机制。该研究成果为认识都龙矿床成矿作用提供了实际地质和地球化学依据。As one of the three largest Sn-polymetallic deposits in China, Dulong ore deposit is located in the southern Laojunshan Sn-Zn-W polymetal mineralization area in south-eastern Yunnan Province, China, and is characterized by complicated geological process, mineralization, and mineral assemblages. Research on mineral assemblages of the deposit indicates four mineralization stages from early to late;（a） skarn stage, the mineral assemblages are dominated by anhydrous skarn（e.g. garnet and diopside） in the early skarn stage and hydrous skarn（e.g. actinolite, epidote, chlorite and vesuvianite）;（b） oxide stage, magnetite, cassiterite and scheelite formed in quantity at the stage;（c） sulphide stage, the mineral assemblages are composed by pyrrhotite, pyrite, chalcopyrite and molybdenite at the early higher temperature stage and sphalerite with minor galena at later lower temperature stage; and（d） carbonate stage, the calcite vein with galena, which occurs around the surface, formed at the stage. The vertical zoning of ore-forming elements and skarn assemblages are related to the distance of concealed granite, corresponding with the typical skarn type deposit, and it is suggested that Dulong deposit is a magmatic hydrothermal skarn type deposit related to Yanshanian granite. The research on fluid inclusion shows that the salinity of ore-forming fluid decreased gradually from the early to the late stage, and the major cassiterite, scheelite and magnetite mineralization formed at high-intermediate temperature and chalcopyrite, sphalerite and galena formed at intermediate-low temperature. It is suggested that the fluid boiling, which caused by the loss of pressure quickly and mixing with meteoric water, is the key mineralization mechanism for ore-forming elements in abundance. The research provides a new geological and geochemical evidence for understanding the mineralization of Dulong Sn-Zn polymetal ore deposit.

关 键 词：都龙锡锌多金属矿床 成矿阶段 成矿流体 岩浆热液夕卡岩型矿床 

分 类 号：P579[天文地球—矿物学] P618.4[天文地球—地质学]