四川攀西地区层状基性-超基性岩体SHRIMP锆石U-Pb年龄及其地质意义  

Zircon SHRIMP U-Pb age of the layered mafic rock mass in Panxi area, Sichuan Province, and its geological significance

作　　者：李华芹[1] 王登红[2] 任海涛[3] 王晓地[1] 贾小辉[1] 杨文强[1] 王磊[1] LI Huaqin;WANG Denghong;REN Haitao;WANG Xiaodi;JIA Xiaohui;YANG Wenqiang;WANG Lei(Wuhan Center of Geological Survey, CGS, Wuhan 430205, Hubei, China;Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China;No.106 Geological Party, Sichuan Bureau of Geology and Mineral Resources Exploration, Chengdu 611130, Sichuan, China)

机构地区：[1]中国地质调查局武汉地质调查中心,湖北武汉430205 [2]中国地质科学院矿产资源研究所,北京100037 [3]四川省地质矿产勘查开发局一○六地质队,四川成都611130

出　　处：《地质通报》2017年第5期691-697,共7页Geological Bulletin of China

基　　金：中国地质调查局项目<中国矿产地质与区域成矿规律综合研究(中国矿产地质志)>(编号:1212011220369)和<全国重要矿产和区域成矿规律研究>(编号:1212010633903)

摘　　要：应用SHRIMP锆石U-Pb测年,对攀西地区白马和太和含矿层状基性-超基性岩体的年龄进行研究,获得白马层状辉长岩体锆石U-Pb年龄为258±2Ma(95%可信度),太和层状辉长岩体锆石U-Pb年龄为262±2Ma(95%可信度)。结果表明,攀西地区的白马和太和含矿层状辉长岩体均形成于二叠纪晚期。该年龄信息显示了从层状辉长岩体的侵入到峨眉山玄武岩的喷发高峰期(250Ma)仅距5~10Ma,二者应属于同期不同阶段岩浆活动的产物。鉴于空间上层状辉长岩体与峨眉山玄武岩密切相关,基性-超基性岩体和玄武岩的形成均与晚古生代末期峨眉地幔柱活动有关。In this paper,based on the application of SHRIMP zircon U-Pb dating method,the authors studied the age of the orecontaininglayered basic-ultrabasic rocks in western Panzhihua area,with the U-Pb ages of zircons from the Baima layered gabbrobody being258±2Ma(95%confidence)and those of zircons from the Taihe layered gabbro body being262±2Ma(95%confidence).These data show that both Baima and Taihe ore-bearing gabbros in western Panzihua metallognetic belt were formed in Late Perm?ian.The age information also suggests that the time gap between the intrusion of the layered gabbro body and the eruption of theEmeishan basalt(peak at250Ma)was only about5~10Ma,and both the intrusive rocks and the basalts should have resulted from mag?matic activities at different stages.Considering the spatial relationship between the layered gabbro body and the Emeishan basalt andconsulting the above age dating results,it is suggested that both the mafic ultramafic rocks and the basalts were formed at the end ofthe late Paleozoic period and associated with the Emei mantle plume activity.

关 键 词：攀西地区 峨眉地幔柱 基性-超基性岩体 SHRIMP 锆石U-PB 定年 白马和太和层状侵入体 

分 类 号：P588.12[天文地球—岩石学] P597.3[天文地球—地质学]