辽中凹陷北段断裂差异演化特征

Differential evolution characteristics of northern Liaozhong Sag

 孙超亚 李坤 任东超 吴昌荣

 （成都理工大学油气藏地质及开发工程国家重点实验室，四川 成都 610059）

 (State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China)

 辽中凹陷北段位于辽东凸起和辽西凸起之间，主要由辽中1号、辽中2号、辽西3号3条断裂组成，断裂走向基本为NE向。断裂倾向由南到北：辽中1号断裂倾向由SE到NW，辽中2号断裂倾向由NW到SE，辽西3号断裂倾向没有太大的变化。倾角有轻微的改变，断裂深度由南到北逐渐变深，伴生断裂增多。辽中凹陷北段构造样式复杂主要构造样式包括伸展构造样式和走滑构造样式，其中以地堑￣半地堑、铲式￣逆牵引、花状构造最为典型。该区域古近纪—新近纪的构造演化期次主要为强烈断陷期、弱伸展裂陷期、断坳强化期和反转期。辽中1号断裂在东营组沉积时期活动强度最大，在馆陶组和沙二段—沙一段沉积时期几乎不活动。辽中2号断裂在东营组沉积时期活动强度最大，表现为走滑活动。辽西3号断裂在孔店组—沙三段沉积时期活动强度最大，在明化镇组—第四系沉积时期停止活动。

 Liaozhong concave section is located in the northern Liaozhong Sag between the Liaodong uplift and Liaoxi uplift. It is constituted by three faults, Liaozhong No.1 Fault, Liaozhong No.2 Fault and Liaoxi No.3 Fault. The main strike of the fault is NE, and the fault dips are as follows: Liaozhong No.1 Fault is from SE to NW; Liaozhong No.2 Fault is from NW to SE; with less strike change and slight dip angle change, the fault depth of Liaoxi No.3 Fault becomes deeper gradually from south to north with more associated faults. The main structural styles are tectonic style and strike-slip tectonic style, including graben-half graben, shovel type-inverse traction, and flower structure, etc. The stages of the regional tectonic evolution are mainly faulted period, weak extensional rifting, faulting depression intensive and phase inversion period. In the depositional period of Dongying Formation, the activity intensity of Liaozhong No.1 Fault is the most active, and almost inactive in the Guantao Group and the first and second Members of Shahejie Formation. Liaozhong No.2 Fault in the depositional period of Dongying Formation is also the most active, showing strike slip activity. The activity intensity of Liaoxi No.3 Fault in Kongdian Formation￣Shahejie Member 3 is most active, and stops activities in the deposition period of Minghuazhen Formation￣sedimentary period of Quaternary.

10.6056/dkyqt201604008