饶阳凹陷构造成因分析

饶阳凹陷是一个东断西超的新生代箕状断陷,内部发育了一系列伸展构造和走滑构造,伸展构造是主体。统计各层位四级断层的走向得出,古近纪由早至晚伸展方向由近东西向到北西–南东向再到近南北向顺时针旋转。右行走滑构造也很明显,表现为雁列构造、帚状构造、花状构造、主断裂尾部构造等主断面陡倾,主要形成于沙三段至东营组沉积期。马西、河间、留路等主控断层的坡坪式形态和伸展活动,导致了自东向西依次为断裂构造带、主洼槽带、中央潜山带、次洼槽带、斜坡的规律性分布。北部主滑脱面深度大,为基底掀斜翘倾区;中部主滑脱面深度较大,为基底断弯区;南部主滑脱面深度较小,为盖层滑脱断褶区。

Analysis of Structural Genesis in Raoyang Sag

Raoyang sag is a Cenozoic halfgraben-like fault depression with faulting in the eastern part and overlapping in the western part, in which a series of extensional and strike-slip structures are developed, dominated by extensional structure. The statistics of 4th-grade faults strikes in each horizon show that they trend from near EW to NW-SE and to near SN in the Early to Late Paleogene by turn clockwise. Dextral strike-slip structure assumes such main fault plane steep-tilting styles as enechelon, brush, flower structures and main fault tail structures, etc., which are primarily formed in the third segment of Shahejie period and Dongying period. The ramp-flat patterns and extensional activities of master faults like Maxi, Hejian and Liulu faults result in regular distribution of the fault belt, major hollow groove belt, central buried hill belt, sub-swamp groove belt and slope from east to west direction. The main detachment plane with big depth in the north is basement-tilted area, the central part with medium depth is basement fault-bend area, and the southern part with small depth is cap rock-slip fault-fold area.