摘要
宗巴音凹陷隶属于蒙古国东戈壁盆地中部坳陷,是在古生界褶皱基底上发育起来的中、新生代凹陷,盆地类型属于反转型断坳叠合盆地,其发育演化以早白垩世的断陷盆地为主体,经历了断陷沉降、断陷反转、坳陷沉降和坳陷反转4个发展阶段。其中,在晚白垩世末的坳陷反转阶段,宗巴音断层沿弧形断面左旋走滑使早期的宗巴音同沉积斜坡带被改造成逆掩断鼻带,凹陷现今的"三隆夹两洼的五分构造格局"最终定型。宗巴音凹陷和二连盆地诸凹陷一样,是东北亚裂谷盆地群的组成部分,但其大地构造环境更靠近蒙古弧形构造的弧顶,处于东部伸展构造样式与西部压缩构造样式的过渡区,因此其构造特征与二连盆地的富油凹陷相对比,既有相似性又有所不同:二者具有相似的构造发育史、相似的复杂内部构造和北东—北北东向为主的断裂构造体系;但盆地类型和发育期、凹陷结构和构造格局、局部构造的成因和形成时间均有差异。
The Zongbayin Sag is subordinate to the depressions in the middle of East Gobi Basin in Mongolia.It is a Meso-Cenozoic sag formed on the Paleozoic fold basement,of which basins are superimposed and depression-faulted of inversion type.The Early Cretaceous rift basins take the majority and they experience four stages of development,i.e.,faulted subsidence,faulted inversion,depression subsidence and depression inversion.At the stage of depression inversion at the end of Early Cretaceous,Zongbayin early synsedimentary slope was transformed into thrusting with broken nose,because of the sinistral strike-slip of Zongbayin fault along the arc-shaped cross-section.So the 'framework of three bulges and two depressions' of the Zongbayin Sag takes shape now.Same as other sags in the Erlian Basin,the Zongbayin Sag is part of rift basin groups in Northeast Asia.However,it is located in the transitional region of the extensional structures in the east and the compression structures in the west,of which the geotectonic environment is more like the top of the Mongolia arc structures.So there is similarity but with difference between the Zongbayin Sag and other oil-rich sags in the basin.They have similar history of structural development,complex inner structures,NE and NNE fracture system.But they have different basin types and development periods,different sag structure and framework,different causes and formation time of local structures.
出处
《中国石油勘探》
CAS
2009年第2期14-22,30,共10页
China Petroleum Exploration
关键词
东戈壁盆地
宗巴音凹陷
二连盆地
构造发育史
构造特征
断裂构造体系
East Gobi Basin
Zongbayin Sag
Erlian Basin
history of structural development
structural characteristics
fracture system
