摘要
为了确定塔中隆起NNE向走滑断裂特征及形成机制,利用构造要素相关性分析及构造解析方法,通过对二维和三维资料的解释,揭示了走滑断裂的构造变形特征,确定了走滑断裂的形成机制。NNE向走滑断裂在地震剖面上表现为压扭和张扭在垂向上叠加的特点,其形成演化主要经历了中奥陶世末压扭和晚志留世—中泥盆世张扭两个阶段。先存基底软弱带和塔里木板块周缘造山带的演化共同控制了这套走滑断裂的形成。中奥陶世末,塔里木板块南缘洋盆俯冲闭合产生的近南北向挤压应力斜向作用于NNE向的基底软弱带之上,导致断裂上部地层被撕裂产生走滑分量,从而形成了北东向的左旋走滑断裂系统,同时,来自塔里木板块西北缘的挤压应力垂向作用于走滑断裂上,导致NNE向走滑断裂发生压扭变形。晚志留世—中泥盆世,塔里木板块南缘的挤压应力继续斜向作用于NNE向走滑断裂之上导致其继续发生走滑变形,同时,来自塔里木盆地西北缘的NW向伸展应力垂向作用于走滑断裂上,导致NNE向走滑断裂发生张扭变形。
In this study, the correlation method of structural factors and structural analysis were used to determine the formationmechanism of NNE- trending strike- slip faults in the Tazhong Uplift. The interpretation of 2D and 3D seismic data revealeddeformation characteristics of the NNE-striking faults and determined their formation mechanism. NNE-trending strike-slip faultsexhibit vertical superposition of compresso- shear faults and tenso- shear faults in seismic profiles. They have experienced two stages of activities： the late Ordovician compresso-shear faulting and the late Silurian-middle Devonian tenso-shear faulting. Theformation of the NNE-trending strike-slip faults was controlled by the pre-existing basement weak zone and the evolution of theorogenic belts around Tarim plate. At the end of Middle Ordovician, a NS- trending compressive stress was generated by thesubduction and closure of the ocean basin on the south margin of Tarim plate, and it acted on the NE-trending basement weak zone,resulting in the formation of NNE- trending strike- slip faults.Meanwhile, the compressive stress from the northwest margin ofTarim plate vertically acted on the NNE-striking strike-slip fault, leading to the compresso-shear deformation. In late SilurianmiddleDevonian period, the NS- trending compressive stress continually acted on the strike- slip faults, resulting in continuedstrike-slip deformation. Moreover, the extensional stress from the northwest margin of Tarim plate vertically acted on the NNEstrikingstrike-slip fault, leading to the tenso-shar deformation.
作者
杨勇
汤良杰
郭颖
谢大庆
YANG Yong TANG Liang-jie GUO Ying XIE Da-qing(Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing 102249, China Basin ＆ Reservoir Research Center, China University of Petroleum, Beijing 102249,China Northwest Oilfield Company,SINOPEC, Urumqi 830011,Xinjiang, China)
出处
《中国地质》
CAS
CSCD
北大核心
2016年第5期1569-1578,共10页
Geology in China
基金
国家自然科学基金项目(4097209
41572105)
国家专项"深部探测与实验研究"(Sino Probe-08-01)联合资助~~
关键词
塔中隆起
断裂体系
走滑断裂
雁列式断层
形成机制
Tazhong uplift
fault system
strike-slip fault
en-echelon faults
formation mechanism
