【摘要】 位于塔里木板块最北缘的东天山库姆塔格沙垄东地区的垄东岩体,侵位于雅满苏石炭纪岛弧带,由早期到晚期可识别出(石英)闪长岩→花岗闪长岩→二长花岗岩3期岩浆活动,锆石U-Pb年龄为261 Ma。里特曼指数(σ)为1.6~2.1,属钙碱性系列;各岩类的主要岩石化学指数随w(SiO2)的变化而呈线性变化,显示出分异良好的同源岩浆序列。岩石地球化学特征及各类图解表明,垄东岩体早期具有典型O型Adakite特征,而晚期则显示出火山弧后碰撞地球化学特征。岩体的两阶段构造演化历程为研究区域大地构造阶段划分和构造格局分析提供了重要佐证。更多还原

【Abstract】 Longdong granitoid rock,located in northern margin of Tarim Plate in Kumutage sand-ridge area,Eastern Tianshan,intruded Carboniferous Yamansu’s island arc zone.Three stages of magmatic impulsive activities can be recognized: the(quartz)diorite,granodiorite,and adamellite from Early to Late periods.Their isotope ages are 216 Ma.Their σ is 1.6—2.1,and they belong to calc-alkali series.Their main petrochemical parameters have regular changes with the variety of SiO2 content which evidenced differentiate evolution features of consanguinity clearly.It is indicated by geochemical data and diagram that Longdong rock is typical O-Adakite in early stage,and is post-orogenic granite in late stage.This offers important evidence for the determination of the regional tectonic evolution stage and tectonic frame.更多还原