塔里木盆地中部满深1断裂带的多期断裂活动

The faults and faulting phases of the Manshen-1 fault belt,central Tarim Basin

满深1断裂带位于塔里木盆地中部的阿满过渡带,走向NNE‑SSW,是三维地震解释发现的一条断裂带。精细的三维地震解释识别出6期断裂,从老到新包括:南华—震旦纪正断层、晚奥陶世—早志留世逆冲断层、中志留世—石炭纪正断层、二叠纪正断层、三叠纪逆冲断层和侏罗纪正断层。中志留世—石炭纪的正断层可以进一步划分为中志留世—中泥盆世正断层和晚泥盆世—石炭纪正断层两期。前者为主,是昆仑—阿尔金早古生代碰撞造山带的造山后构造;后者是前者的复活。中志留世—石炭纪正断层作用形成一系列近南北走向的正断层,组合成一条NNE‑SSW走向的右列左旋张扭性断层带,形成满深1断裂带。二叠纪裂谷作用成因的正断层和岩浆活动显著改造断裂带,使之基本定型。三叠纪的冲断构造叠加于依合2构造之上。侏罗纪伸展作用对构造带有一定的调整影响。南华—震旦纪正断层和晚奥陶世—早志留世的冲断构造与满深1断裂带相交,对构造带的形成影响不大。侏罗纪正断层的发现,是塔里木盆地当时处于区域性伸展构造背景的重要证据。

The Manshen-1 fault belt trending in NEE-SWW direction and located in the central Tarim Basin was revealed during our careful 3D seismic interpretation.It is consisted of numerous faults.In this structural belt,6 faulting phases have been identified after careful and systematic seismic interpretation.They are the Nanhua-Sinian normal faulting,Late Ordovician-Early Silurian thrusting,Middle Silurian-Carboniferous normal faulting,Permian normal faulting,Triassic thrusting and Jurassic normal faulting.The Middle Silurian-Carboniferous normal faulting phase can be divided into the Middle Silurian-Middle Devonian and Late Devonian-Carboniferous normal faulting sub-phases.The former is possibly the post-collision structure of the Kunlun-Altun Early Paleozoic collisional orogenic belt,and the later is the former's reactivation.The Middle Silurian-Carboniferous normal faulting formed a series of normal faults trending N-S.They are arranged horizontally in right-step,en echelon patterns,forming a sinistral transtensional fault belt which is just the Manshen-1 fault belt.The Permian rift-related normal faulting and magmatism obviously reprinted the belt.The Triassic thrusting superimposed on the Yihe-2 structure,part of the Manshen-1 fault belt.The Jurassic normal faulting exert some adjustment on the belt.The new discovery of the Jurassic normal faults in the central Tarim Basin illustrates the regional extensional tectonic setting in Jurassic.The Nanhua-Sinian normal faulting and Late Ordovician-Early Silurian thrusting have few influence on the formation of the Manshen-1 fault belt.