摘要
莺歌海盆地关键断层与红河断裂带的运动学特征与动力学成因机制存在争议.本文利用地层回剥技术和平衡剖面恢复方法,分析莺歌海盆地重要断层在不同时期的盆地沉降量和伸展量,探讨红河断裂带构造活动与莺歌海盆地形成演化过程.研究表明,在30~21 Ma期间走滑作用主要集中在Song Lo断层附近,水平伸展作用较弱;同时期的水平伸展作用主要集中在Chay断层一带.沉降中心位于河内凹陷的Chay断层、Thai Binh断层与东西向断层带的叠加区域.21~15.5 Ma期间,盆地北部发生构造反转,在临高凸起挤压隆升最为剧烈,Song Lo断层、莺东和东方断层均发生不同程度的构造反转.Song Lo断层与红河断裂带的活动特征相似,莺东断层与东方断层是Song Lo断层在莺歌海盆内的南部延伸.印支地块逃逸过程同时伴随着重要的区域伸展过程,走滑逃逸沿着莺歌海盆地东侧的边界断层发生,而区域伸展作用在盆地内部及外围普遍存在,构造反转与陆上左行剪切活动减弱和印支地块的旋转停止有关.
The kinematic characteristics and dynamic mechanisms of key faults in the Yinggehai Basin and the Red River Fault Zone remain controversial.This study applies stratigraphic backstripping and balanced cross-section restoration to quantify subsidence and extensional rates of major faults in the Yinggehai Basin across different geological periods,aiming to clarify the tectonic activity of the Red River Fault Zone and the basin′s evolutionary history.Results show that between 30 and 21 Ma,strike-slip faulting was primarily concentrated along the Song Lo Fault,while horizontal extension remained relatively minor.During this period,significant extensional deformation was localized in the Chay Fault zone.The main subsidence center was located in the Hanoi Depression,especially in the overlap zone of the Chay Fault,Thai Binh Fault,and east-west trending fault systems.From 21 to 15.5 Ma,tectonic inversion occurred in the northern basin,with the most intense compressional uplift centered on the Lingao Uplift.Concurrently,the Song Lo,Yingdong,and Dongfang Faults experienced varying degrees of tectonic inversion.The tectonic behavior of the Song Lo Fault mirrors that of the Red River Fault Zone,with the Yingdong and Dongfang Faults acting as southern extensions of the Song Lo Fault within the Yinggehai Basin.The escape tectonics of the Indochina Block was marked by substantial regional extension,with strike-slip deformation occurring along boundary faults on the eastern margin of the Yinggehai Basin,while extensional tectonics was widespread both within and around the basin.The observed tectonic inversion is closely linked to the reduction of left-lateral shear along onshore faults and the cessation of rotational motion of the Indochina Block.
作者
谢海洋
史冠中
王华
王羽飞
刘思云
魏驿超
杨冬冬
Xie Haiyang;Shi Guanzhong;Wang Hua;Wang Yufei;Liu Siyun;Wei Yichao;Yang Dongdong(Key Laboratory of Tectonics and Petroleum Resources,Ministry of Education,China University of Geosciences,Wuhan 430074,China;China National Nuclear Power Co.,Ltd.Jiangsu Branch,Lianyungang 222042,China)
出处
《地球科学》
北大核心
2025年第8期3034-3051,共18页
Earth Science
基金
国家自然科学基金联合基金项目(No.U19B2007)
国家自然科学基金面上项目(Nos.42072142,42172182)。
关键词
红河断裂带
莺歌海盆地
构造沉降
伸展量
构造反转
构造学
Ailao Shan-Red River Shear Zone
Yinggehai Basin
tectonic subsidence
amount of extension
inversion
tectonics
