摘要
东北地区主要由东部佳木斯地块、中部兴安—松嫩地块和西部额尔古纳地块构成,各地块之间主要构造带拼合时代的研究表明,晚古生代之前各地块之间已经完成拼合,形成了统一的佳—蒙地块。晚古生代开始东北地区进入统一的盖层演化阶段,在佳—蒙地块南缘发育了晚古生代具有大陆边缘沉积特征的盖层建造。晚古生代早期佳—蒙地块南缘为活动陆缘,在～320Ma向北的俯冲过程中古亚洲洋板块发生断离,形成火山弧,同时导致其北侧"贺根山"弧后洋的拉开,持续的向北俯冲导致弧-陆碰撞,并于～280Ma贺根山洋已经完全闭合。佳—蒙地块南缘开始由活动陆缘向被动陆缘环境转化,最后在晚二叠世末期古亚洲洋完全闭合转入内陆环境。
Northeast China area consists of several micro-continental blocks,such as Jiamusi Block in the southeast,Xing＇an-Songliao Block in the middle,and Erguna blocks in the northwest.Studies of the suture zones between the blocks indicate that the amalgamation of these blocks ended before Late Paleozoic and formed a big continental block,i.e.,Jia-Meng Block.From Late Paleozoic the cover sequences started to develop and formed a Late Paleozoic continental margin cover sequence.The tectonic setting of the southern margin of the Jia-Meng Block was an active continental margin during early Paleozoic.The Paleo-Asian ocean plate broke down during the northward subduction around 320 Ma,and formed a volcanic arc.Meanwhile the Hegenshan back-arc basin ocean was opened.The continuous northward subduction resulted in the arc-continent collision,and the Hegenshan Ocean was closed at 280 Ma.The tectonic setting changed from active margin to passive margin.Finally the Paleo-Asian ocean was closed at the end of Late Permian,and the whole area became an intracontinental terrestrial setting.
出处
《中国地质》
CAS
CSCD
北大核心
2010年第4期943-951,共9页
Geology in China
基金
国家自然科学基金重点项目(40739905)
博士点基金项目(No.200801830041)
中国石油化工股份有限公司科技开发项目(G0800-06-ZS-327)
国家留学基金建设高水平大学公派研究生项目(2008617114)联合资助
关键词
晚古生代
古亚洲洋
西拉木伦河缝合带
佳—蒙地块
东北
Late Proterozoic
Paleo-Asian Ocean
Xar Moron River suture zone
Jia-Meng Block
Northeast China
