鞍山地区铁架山花岗岩中表壳岩的碎屑锆石SHRIMP年龄及其地质意义  

Formation time of supracrustal rocks in Tiejiashan granite of the Anshan area:evidence from detrital zircon SHRIMP dating

作　　者：殷小艳[1] 万渝生[1] 刘敦一[1] Simon A Wilde 周红英[1] 伍家善[1] 

机构地区：[1]中国地质科学院地质研究所 [2]西澳柯廷大学地质系

出　　处：《岩石矿物学杂志》2006年第4期282-286,共5页Acta Petrologica et Mineralogica

基　　金：国土资源部地质调查项目(1212010561608)

摘　　要：鞍山地区3.0Ga铁架山花岗岩是华北克拉通时代最古老、分布范围最大的钾质花岗岩,其中存在较多成熟度高的变泥沙质岩石表壳岩,其元素和Nd同位素组成与铁架山花岗岩十分相似。以往研究把它们作为铁架山花岗岩中的表壳岩包体,认为铁架山花岗岩形成于它们的部分熔融。本文利用碎屑锆石SHRI MP U-Pb定年方法对鞍山铁架山花岗岩中变泥沙质表壳岩的形成时代进行了制约,证实表壳岩形成于铁架山花岗岩之后,为遭受强烈变质变形地区变泥沙质岩石时代研究提供了一个新的实例。The 3.0 Ga Tiejiashan granite in the Anshan area is the oldest and largest potassium granite intrusion in the North China Craton. Meta-sedimentary rocks with high maturity in the Tiejiashan granite were once considered to occur as enclaves and to be a main resource from which the Tiejiashan granite came. However, SHRIMP U-Pb dating of detrital zircons from three meta-sedimentary samples commonly gives the ages of -3.0 Ga, being the same as the formation time of the Tiejiashan granite. Therefore, the supracrustal rocks should have been formed after 3.0 Ga, with a tectonic relationship with the granite. It is considered that the supracrustal rocks dated in this study are a part of the 2.5 Ga Anshan Group.

关 键 词：SHRIMP 碎屑锆石 表壳岩 花岗岩 太古宙 鞍山 

分 类 号：P597.3[天文地球—地球化学] P588.3[天文地球—地质学]