辽东北辽河群斜长角闪岩的地球化学特征及构造背景  

Geochemical Characteristics and the Tectonic Setting of Amphibolites of the North Liaohe Group in Liaodong Area

作　　者：马立杰[1] 崔迎春[1] 刘俊来[2] 张俊波 

机构地区：[1]中国科学院海洋研究所海洋地质与环境重点实验室,山东青岛266071 [2]中国地质大学,北京100083 [3]山东省地质科学实验研究院,山东济南250013

出　　处：《山西大学学报（自然科学版）》2007年第4期515-523,共9页Journal of Shanxi University(Natural Science Edition)

基　　金：国家海洋局青年基金(No.2005304)

摘　　要：辽河群是一套分布在辽东地区的早元古代变质岩系,分为南辽河群和北辽河群.为了探讨北辽河群的大地构造背景,对分布在北辽河群的斜长角闪岩进行了岩石学研究.结果表明北辽河群中的斜长角闪岩所含主要矿物为角闪石和斜长石.稀土元素总量在45.99μg/g^77.71μg/g之间变化,属于贫稀土型;轻稀土相对富集,稀土配分曲线呈右倾,无Eu异常或弱的Eu正异常;微量元素中大离子亲石元素富集.这些特征表明其原岩为石英拉斑玄武岩,形成的构造环境为大洋岛弧环境.Liaohe Group is one early proterozoic metamorphic unit which located in Liaodong area and it is divided into Southern Liaohe Group and Northern Liaohe Group. In order to discuss the tetonic setting of north-Liaohe Group,the petrographic characters of North-Liaohe Group amphibolites were analyzed. The results showed that the main minerals of amphibolites were the amphibolite and the plagioclase. The total rare elements ranged from 45.99 μg/g to 77.71 μg/g,belonging to deficient rare element type. The light rare elements are richer than heavy rare elements and their distribution patterns showed the right slope and had no Eu abnormity or poor positive abnormity. The features above discussed clarify that the protoliths of Amphibolites was the quartz tholeiitic and formed under ocean island arc tectonic-environment.

关 键 词：北辽河群 斜长角闪岩 岩石化学 大洋岛弧 

分 类 号：P591[天文地球—地球化学]