新疆东天山觉罗塔格地区自然铜矿化玄武岩的成岩年代及其地质意义  

Geochronology and geological indication of the native copper mineralized basalt formation in Jueluotage area,Eastern Tianshan,Xinjiang

作　　者：张达玉[1] 周涛发[1] 袁峰[1] 刘帅[1] LU YongJun 许超[1] 宁福泉 

机构地区：[1]合肥工业大学资源与环境工程学院,合肥230009 [2]澳大利亚西澳大利亚大学勘探靶区中心,珀斯6009 [3]新疆鑫汇地质矿业有限责任公司,乌鲁木齐830011

出　　处：《岩石学报》2012年第8期2392-2400,共9页Acta Petrologica Sinica

基　　金：“十二五”国家科技支撑计划(2011BAB06B01);国家重点基础研究发展规划项目(2007CB411304、2001CB409800);新世纪优秀人才支持计划项目(NCET-10-0324);国家自然科学基金项目(40772057、41040025);矿床地球化学国家重点实验室开放基金(201102)联合资助

摘　　要：新疆觉罗塔格地区自然铜矿化玄武岩沿着阿齐库都克深大断裂北侧分布,前人对其成岩年代一直存在争议。本文测得玄武岩条带中部的黑尖山玄武岩同岩浆期锆石SHRIMPU-Pb年龄为306.2±4.0Ma;测得东部东尖峰玄武岩的同岩浆期锆石LA-ICPMSU-Pb年龄为308.9±5.8Ma,确定了玄武岩是晚石炭世的岩浆作用,且归属于晚石炭世马头滩组。与觉罗塔格地区著名的晚石炭世-早二叠世铜镍矿化基性-超基性岩成因对比表明,该晚石炭世玄武岩与之具有共同岩浆源区特征,它们都是觉罗塔格地区晚石炭世-早二叠世岩石圈地幔深部受热熔融而形成岩浆作用。马头滩组玄武岩层是自然铜矿化的重要矿源层。The native copper mineralized basalt （NCMB） distributes north side along with the Aqikuduke deep fault, Jueluotage area, Eastern Tianshan, Xinjiang. As the basaltic magmatism erupted epoch hasn＇t been acknowledged yet, this study focuses on the geology and geochronology of the NCMB strata. The authors got the in-situ SHRIMP U-Pb age of basalts sampled from Heijianshan Cu- Fe mineralized occurrence （ middle study area） is 306. 2 ± 4. 0Ma; and the in-situ La-ICPMS U-Pb age of basalt sampled from Dongjianfeng native copper mineralized occurrence （ east study area） is 308. 9 ± 5.8Ma. These two confident and coherent ages can be used for confirming that the basalt bearing in Lower Matoutan Formation is the product of Late Carboniferous magmatism. After compared geochemical characters and genesis with the C2-P1 Cu-Ni sulfide mineralized mafic-ultramafic intrusions in Jueluotage area, It shows that the NCMB shared the same magmatic source with the younger one, and both NCMB and mafic-ultramafic intrusions were the products of the mafic magma, which were derived from the same vulnerable lithosphere mantle through some geodynamic heat abnormalities in Jueluotage area. The basaltic stratum is an important metal source of the Cu mineralized occurrence bearing in the Matoutan Formation.

关 键 词：玄武岩 SHRIMP LA-ICPMS 马头滩组 觉罗塔格 东天山 

分 类 号：P588.145[天文地球—岩石学] P597.3[天文地球—地质学]