摘要
招远—莱州地区花岗岩类锆石 S H R I M P 研究表明,该区花岗岩类含有大量不同时代的继承锆石。3446 ±2 Ma ~3114 ±4 Ma 继承锆石的发现,表明鲁东地区存在古太古代硅铝核。大量印支期继承锆石的年龄( 平均年龄219 Ma) 与华南、华北克拉通碰撞时代一致,推测这些锆石极可能来自其源岩———华南、华北克拉通碰撞造山花岗岩,从而否定了玲珑型花岗岩主要是由胶东岩群交代 重熔形成的传统认识。郭家岭型花岗闪长岩中含有较多新太古代和古元古代继承锆石,表明其源岩有较多的胶东岩群和荆山岩群变镁铁质岩石和( 或) T T G 岩系的硅铝质岩石。
According to the SHRIMP research of inherited zircons in the granitoid in Zhaoyuan-Laizhou area, it is showed that lots of different age′s inherited zircons are there.The discovery of the inherited zircons with the ages from 3446±2 to 3114±4Ma demonstrates that there is early-archean sialic crust in Jiaodong area. Lots of the inherited zircons of indochina stage averaging at the age of 219Ma possess the same age as the collison between North China and South China crators, and these inherited zircons are inferred probably from the collsional granites formed by the collision. Thus, the traditional recognition that Linglong granites were formed by metasomatism-remelting of Jiaodong group has been denied. Lots of inherited zircons at the age of late-Archean and Proterozoic are included in Guojialing granites, which showed that the source rocks consist partially of meta-mafic rocks of Jiaodong and Jingshan group and/or sialic rocks of TTG rock series.
出处
《山东地质》
1999年第3期24-30,共7页
Geology of Shandong
关键词
花岗岩类
继承锆石
源岩
重熔
锆石年龄
Granites
inherited zircon
source rock
remelting
Wulian-Rongcheng fault belt