云南万龙山锡锌多金属矿床闪锌矿Rb-Sr等时线年龄及其地质意义  

Rb-Sr isochron age of sphalerite in the Wan longshan Zn-Sn Polymetallic Deposit and its geological significance

作　　者：何显川 艾金彪[1] 魏宇[1] 牟明海 张韬[1] HE Xian-chuan;AI Jin-biao;WEI Yu;MU Ming-hai;ZHANG Tao(Sichuan Institute of Metallurgical Geology and Exploration,Chengdu 610051,China)

机构地区：[1]四川省冶金地质勘查院,四川成都610051

出　　处：《世界有色金属》2021年第17期90-93,共4页World Nonferrous Metals

摘　　要：云南万龙山锡锌矿是都龙锡矿的一个重要矿段,本次首次对万龙山矿床开展闪锌矿Rb-Sr同位素定年研究,获得的Rb-Sr等时线年龄为(75.0±3.0)×10;a,表明闪锌矿的成矿年龄略晚于锡石成矿年龄。初始锶同位素组成ISr=0.7196±0.0045,锶比值几乎和大陆壳古老硅铝质岩石(0.720±0.005)接近。本文对矿床中闪锌矿矿物的锶同位素进行了系统研究,初步认为万龙山锡锌矿床中的金属元素极有可能来源于前寒武系的基底变质岩和矿区隐伏的老君山花岗岩体。综合以往区域矿床成因研究成果,认为万龙山锌锡矿成矿时代应在晚白垩纪,且区内燕山晚期的岩浆热液活动对其有强烈叠加作用,是华南中生代白垩纪中期大规模成矿作用的结果。The Dulong Sn-Zn polymetallic deposit is one of the largest cassiterite-sulfide deposits in China,WanLongshan is an important section.This is the first time to carry out a study on the dating of Rb-Sr isotope in the Wanlong Mountain deposit.The obtained Rb-Sr isochronous age is(75.0±3.0)×10;a.This shows that the metallogenic age of sphalerite is slightly later than that of cassiterite.The initial strontium isotope composition ISr=0.7196±0.0045 is consistent with the strontium ratio of the ancient Silicon aluminum rock of the continental shell(0.720±0.005).In the study of strontium isotope,the metallogenic metals are mainly derived from the Metamorphic rocks and Laojunshan granites.Based on the results of diagene-metallogenic research,it is shown that the metallogenic activity of zinc-tin occurred mainly in the late late Cretaceous period,and was closely related to the hydrothermal reaction of Laojunshan granite magma in the late Yanshan period.

关 键 词：锡锌多金属矿床 万龙山 RB-SR同位素 成矿时代 

分 类 号：P618.2[天文地球—矿床学]