金顶铅锌矿黄铁矿Re-Os定年及其地质意义  

Re-Os Isotopic Dating of Pyrite from Jinding Zn-Pb Ore Deposit and Its Geological Significance

作　　者：唐永永[1,2] 毕献武[1] 武丽艳[1] 王雷[3] 邹志超[1,2] 和利平 

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,北京100049 [3]中国地质大学,湖北武汉430074 [4]云南金鼎锌业有限公司,云南兰坪671401

出　　处：《矿物学报》2013年第3期287-294,共8页Acta Mineralogica Sinica

基　　金：国家重点基础研究发展规划项目(编号:2009CB421005);中国科学院重要方向项目群项目(编号:KZCX2-YW-Q04-01)

摘　　要：关于金顶铅锌矿的成矿时代至今未获得精确的同位素测年数据,这严重制约了我们准确厘定该矿的成矿动力学背景。鉴于此,本文根据黄铁矿的产状特征,将其区分为沉积成岩期和热液期黄铁矿,并开展了Re-Os同位素测年的研究(ICP-MS方法)。虽然黄铁矿的R(e0.4069×10-9～375.2620×10-9)和O(s 0.0008×10-9～0.4131×10-9)含量变化很大,部分样品含量很低,但它们仍然揭示出两组等时线年龄:分别为114±13 Ma和65±10 Ma。笔者认为114 Ma等时线年龄可能代表了沉积成岩过程当中的一期矿化年龄,而65 Ma可能记录了铅锌主矿化之前热液作用开始活动的时间。结合其他方面的地质证据推断金顶铅锌矿主矿化时代可能在28～37 Ma之间。In this study,Re-Os isotopes of pyrite from the Jinding Pb-Zn deposit were carried out by ICP-MS method.According to occurrences of pyrite,they were identified as sedimentary diagenetic pyrite and hydrothermal pyrite,and showed large variation in contents of Re（0.4069×10-9-375.2620×10-9） and Os（0.0008×10-9-0.4131×10-9）,with low contents of Re and Os in some samples,they display two isochron ages of 114±13 Ma and 65±10 Ma,respectively.Combined with other geological evidences,it is concluded that the two ages could not represent the epoch of the main mineralization which are assessed at 37-28 Ma based on other geological constraints.However,114 Ma is likely related to a mineralization event during diagenesis,while 65 Ma might indicate the beginning of hydrothermal mineralization of Jinding Zn-Pb deposit.

关 键 词：RE-OS同位素 黄铁矿 成矿时代 金顶铅锌矿 

分 类 号：P618[天文地球—矿床学] P597[天文地球—地质学]