白云鄂博REE-Fe-Nb矿床碳酸岩墙锆石U-Pb年龄及其地质意义  

Zircon U-Pb age of a carbonatite dyke from Bayan Obo REE-Fe-Nb deposit, Inner Mongolia and its geological significance.

作　　者：范宏瑞[1] 陈福坤[1,2] 王凯怡[1] 谢奕汉[1] Simon W ILDE Muharrem SATIR 

机构地区：[1]中国科学院地质与地球物理研究所矿产资源研究重点实验室 [2]德国蒂宾根大学矿物岩石地球化学研究所,德国蒂宾根72074 [3]澳大利亚柯廷技术大学应用地质系

出　　处：《岩石学报》2002年第3期363-368,共6页Acta Petrologica Sinica

基　　金：国家自然科学基金项目 (编号 :49972 0 3 6);国家重点基础研究项目 (编号 :G19990 75 5 0 2 )资助

摘　　要：对白云鄂博稀土 -铁 -铌矿矿区一火成碳酸岩内锆石 U - Pb年龄进行了测定 ,五颗锆石测定数据点拟合直线与谐合线的上交点年龄为 2 0 70± 33Ma,表明白云鄂博矿区火成碳酸岩脉的侵入时代最早可以追溯到早元古代 ,该年龄与矿区内正长岩和英云闪长岩锆石年龄等接近 ,构成了形成于裂谷环境的白云鄂博早元古代碱性岩Zircon U Pb age of a carbonatite dyke from the Bayan Obo giant REE Fe Nb deposit is presented in this study and its geological implications are discussed. Five zircon fractions from this dyke well define a discordia giving an upper intercept model age of 2070±33 Ma. This Paleoproterozoic model age is interpreted as crystallisation time of the carbonatite dyke. Similar U Pb zircon ages were reported for syenites and tonalites from the same area. Based on the geochronological data, it is considered that these Paleoproterozoic rocks from the Bayan Obo deposit as an alkaline rock carbonatite complex were probably formed in a rift environment.

关 键 词：锆石U-PB年龄 火成碳酸岩 早元古代 白云鄂博矿区 REE-Fe-Nb矿床 

分 类 号：P588.15[天文地球—岩石学] P597[天文地球—地质学]