云南个旧卡房蚀变玄武岩金云母^(40)Ar-^(39)Ar同位素年龄研究及意义  

^(40)Ar-^(39)Ar isotopic age study of phlogopite from Kafang altered basalt in Gejiu of Yunnan Province and its significance

作　　者：张娟[1] 毛景文[1,2] 程彦博[1,3] 李肖龙[1] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]中国地质科学院矿产资源研究所,北京100037 [3]School of Earth and Environmental Sciences,James Cook University

出　　处：《中国地质》2012年第6期1647-1656,共10页Geology in China

基　　金：国家自然科学基金重点项目(40930419);国土资源部公益性行业科研专项(200911007-12);云南锡业集团有限责任公司科研项目(2010-04A);中国地质调查局地质调查项目(1212011120994)资助

摘　　要：云南个旧锡铜多金属矿床是世界级超大型矿床,个旧矿集区内与蚀变玄武岩有关的(似)层状铜矿床是其重要的矿床类型。该类型矿床的围岩玄武岩均发生蚀变,且蚀变强度与矿化关系密切。本文对个旧卡房矿化玄武岩中的金云母进行40Ar-39Ar同位素定年分析,得到其坪年龄为(85.49±0.63)Ma,等时线年龄为(85.62±0.42)Ma,反等时线年龄为(85.59±0.81)Ma,三者基本一致,代表了变玄武岩的蚀变年龄及同期矿化年龄,属于晚白垩世,可与个旧锡铜多金属矿床的成矿时代进行对比。The Gejiu polymetallic tin ore district in Yunnan Province is the largest tin deposit in the world,and the Kafang copper（tin） deposit is a component part of this ore district.The stratoid ore body of the Kafang copper（tin） deposit,closely related to meta-basalt,is characterized by enriched copper.The basalt has been altered and the alteration intensity is related to the copper mineralization.This paper presents a new 40Ar-39Ar phlogopite age for the meta-basalt in the Kafang tin-copper deposit in order to constrain the timing and duration of the alteration of basalt and the mineralization.Phlogopite yielded 40Ar-39Ar plateau age of 85.49±0.63 Ma,isochronal age of 85.62±0.42 Ma,and inverse isochronal age of 85.59±0.81 Ma.These ages are substantially consistent with each other,pointing to late Cretaceous.These results are coincident with the data obtained from the Gejiu polymetallic tin-copper deposit.

关 键 词：40Ar-39Ar同位素年龄 金云母 矿化蚀变玄武岩 个旧卡房铜矿 

分 类 号：P597[天文地球—地球化学] P588.145[天文地球—地质学]