辽北清原地区红透山组斜长角闪岩地球化学特征及成因  

Geochemical characteristics and genesis of plagioclase amphibolites of Hongtoushan Formation in Qingyuan area,Northern Liaoning Province

作　　者：杨新宇 YANG Xinyu(Liaoning Geological and Mineral Survey Institute CO.,LTD,Shenyang 110031,Liaoning,China)

机构地区：[1]辽宁省地质矿产调查院有限责任公司,辽宁沈阳110031

出　　处：《吉林地质》2021年第3期15-21,共7页Jilin Geology

基　　金：中国地质调查局“辽宁1∶5万厦家堡镇、猴石、北三家、清原县幅区域地质矿产调查(DD20160049-9)”资助。

摘　　要：对辽北清原地区出露的红透山组斜长角闪岩开展了详细的野外地质考察和室内岩相学、地球化学研究分析,探讨了该斜长角闪岩的成因以及形成背景。研究表明,红透山组斜长角闪岩属于正变质岩,火山成因,具有钙碱性系列岩石地球化学特征,原岩为拉斑玄武岩。岩石轻稀土相对富集且轻重稀土分馏较明显,Eu异常(0.91~1.06)不明显,微量元素中较富集K、Rb、Ba等大离子亲石元素(LILE),亏损Ti、Nd、Ta等高场强元素,显示出其原岩具有消减带岩浆的特征,形成于岛弧构造环境。结合近年来区域上的研究成果,认为辽北清原地区是华北克拉通新太古代吉-辽-冀弧陆碰撞增生造山带的重要组成部分。Based on the detailed field geological investigation and indoor petrographic and geochemical analysis on the plagioclase amphibolites of Hongtoushan Formation in Qingyuan area,Northern Liaoning Province,we discussed on the genesis and formation background of the amphibolite.The study shows that the plagioclase amphibolite of Hongtoushan Formation belongs to orthometamorphic rock and is of volcanic origin,with the geochemical characteristics of calc-alkaline series,and the original rock belong to tholeiitic basalt.The light rare earths in the rocks are relatively enriched and the fractionation of light and light rare earths is obvious,the EU anomaly(0.91~1.06)is not obvious,the trace elements are relatively enriched in large ion lithophile elements(LILE),such as K,Rb and Ba,and are deficient in high field strength elements(HFSE),such as Ti,Nd and Ta,showing that the original rock has the characteristics of subduction zone magma and was formed in the island arc tectonic environment.Combined with the regional research results in recent years,they jointly indicate that the Qingyuan area is an important part of the Jilin-Liaoning-Hebei arc-land collision accretion orogen in the Neoarchean North China Craton.

关 键 词：斜长角闪岩 地球化学 拉斑玄武岩 钙碱性系列 岛弧环境 

分 类 号：P588.3[天文地球—岩石学]