松辽盆地基底显生宙岩浆热事件：来自营城组火山岩捕获锆石的SHRIMP定年证据  

Phanerozoic magmatic events in the basement of Songliao basin:SHRIMP dating of captured zircons from Yingcheng Formation volcanic rocks.

作　　者：余星[1] 肖骏[1] 陈汉林[1] 章凤奇[1,2] 徐岩[1] 董传万[1] 庞彦明[2] 

机构地区：[1]浙江大学地球科学系,教育部含油气盆地构造研究中心,杭州310027 [2]大庆油田勘探开发研究院,大庆163712

出　　处：《岩石学报》2008年第5期1123-1130,共8页Acta Petrologica Sinica

基　　金：国家重点基础研究发展规划项目(2007CB411307);国家重点基础研究发展规划项目(2001CB409801)联合资助

摘　　要：盆地基底的研究对了解成盆历史及恢复区域古大地构背景具有重要意义。本文从松辽盆地北部早白垩世营城组火山岩的显生宙基底捕获锆石入手,对其进行 SHRIMP U-Pb 定年,得到7组显生宙年龄:482～481Ma、381～350Ma、297～290Ma、252～237Ma、225～219Ma、200～189Ma、183～158Ma。研究认为松辽盆地北部显生宙基底至少经历了晚泥盆世、早二叠世早期、三叠纪和早-中侏罗世等多次大规模的岩浆热事件,其中以中生代三叠纪和侏罗纪火山活动最为频繁,中生代火成岩是松辽盆地显生宙基底花岗岩的主体。这一系列显生宙的岩浆活动可能与晚古生代额尔古纳-兴安、松嫩-张广才岭、佳木斯-兴凯等地块相互间碰撞拼合后的岩石圈伸展作用、华北板块和西伯利亚板块在二叠纪末期碰撞拼合(古亚洲洋闭合造山)后的岩石圈伸展作用、侏罗纪佳木斯地块西缘洋壳俯冲并与松嫩地块拼合作用、东北亚古亚洲洋构造域向太平洋构造域转换等古大地构造运动有关。482～481Ma 为变质成因锆石的年龄,代表了早奥陶世(Tremadocian 阶)松辽盆地基底的变质增生作用,该变质过程可能与盆地西北部额尔古纳地块与兴安地块的拼合作用。Basement research to a basin is of greatonic setting. This importance to know the basin genesis and rebuild the paleo-tectpaper is trying to study the captured Phanerozoic zircons in Early Cretaceous YingCheng Formation volcanic rocks by SHRIMP U-Pb dating. There are 7 age groups for the captured zircons： 482 -481Ma, 381 -350Ma, 297 -290Ma, 252 -237Ma, 225 -219Ma, 200 - 189Ma, 183- 158Ma, which means there happened large scale magmatic events in Late Devonian, Early Permian, Triassic and Early-Middle Jurassic. Among them Triassic and Jurassic magmatic rocks compose the main part of Phanerozoic base granitoid rocks. These Phanerozoic magmatism is quite possibly related to paleo-teetonic movements, such as lithophere extention following the collision of the Ergula-Xing＇ an, Songnen-Zhangguangcailing and Jiamusi-Xingkai block during Late Paleozoic, and lithosphere extention following the collision between North China Block and Siberia Block in Late Permian, and Combination of Jiamusi and Songnen block in Jurassic, as well as the transition of tectonic domain from Paleo-Asia Ocean to Pacific. Besides, 482 -481Ma is the age for a metamorphic captured zircon, which indicates the metamorphism happened in the basement of Songliao basin around Early Ordovician. And that was probably influenced by the collision of Ergula and Xing＇ an Block which was near to the basin.

关 键 词：松辽盆地 捕获锆石 SHRIMP U—Pb定年 显生宙基底 岩浆热事件 

分 类 号：P597.3[天文地球—地球化学]