东天山大草滩北镁铁超镁铁岩锆石U-Pb年龄、地球化学特征及其地质意义

发布时间：2018-04-22 03:35

本文选题：镁铁超镁铁岩 + SSZ型蛇绿岩　；参考：《矿物岩石地球化学通报》2017年01期

【摘要】：为探讨新疆北天山古生代大地构造格架及其演化,对吐哈盆地南缘古生代天窗新发现的大草滩北镁铁-超镁铁岩进行了地球化学和U-Pb定年研究。结果表明,该镁铁质-超镁铁质岩石由玄武岩、辉长岩、辉橄岩、辉石岩和蛇纹石化超基性岩组成。其轻稀土富集、重稀土相对亏损,有较弱的同化混染作用,玄武岩具有岛弧火山岩和洋中脊火山岩双重特性,可能与康古尔蛇绿岩一样产于弧后盆地环境的蛇绿岩(SSZ型)。本次研究获得的辉长岩的LA-ICP-MS锆石~(206)Pb/U~(238)年龄为416.5±4 Ma,为晚志留世,说明古亚洲洋初始主碰撞持续到志留纪晚期。
[Abstract]:In order to study the geotectonic framework and its evolution in the Paleozoic in North Tianshan Mountains in Xinjiang , the authors have conducted geochemical and U - Pb dating studies on the newly discovered heavy rare earth iron - ultramamagmatite in the southern margin of the Tuha basin . The results show that the Mg - Fe - Mg - Fe - Mg - Fe - Mg - Fe - Mg - Fe - rock consists of basalt , gabbro , fazite , pyroxenite and serpentine ultrabasic rock . The results show that the zircon - MS zircon - ( 206 ) Pb / U ~ ( 238 ) age of the gabbro is 416.5 卤 4 Ma , which indicates that the initial main collision of the ancient Asian ocean continued to the later stage .

【作者单位】：新疆维吾尔自治区地质调查院;新疆地质矿产局;
【基金】：中国地质调查局地质调查项目(12120114059201)
【分类号】：P597.3;P588.1

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