岐口凹陷沙一段古地貌单元组合样式

Palaeogeomorphology Unit Pattern of Qikou Sag in the First Member of Shahejie

摘要: 歧口凹陷是渤海湾盆地最重要富油气凹陷之一。岐口凹陷沙一段大量发育不同类型和成因的古沟谷、古坡折带和其他古地貌单元。其相互耦合，组成面貌迥异的物源供给系统，制约了沉积层序的位置、规模、内部构成和充填样式。有必要对这些组合样式进行研究。本文在岐口凹陷沙一段内识别出古地貌组合样式有隆起–缓坡多级断阶坡折带–凹陷组合、凹陷–大型断槽–凹陷组合、凸起–断裂沟槽–陡坡断裂坡折–凹陷组合和水下低隆起–生物礁滩组合四种古地貌单元组合样式。

Abstract: Qikou sag is one of the most important fuel-rich sags in Bohai bay basin. A large number of paleo-geosyncline, paleoslop break and other geomorphic units in different forms and for different causes are developed in the first member of Shahejie in Qikou sag. They copule with each other, construct different provenance supplement systems, and restrict sedimentary sequence’s location, dimensions, internal composition and packing style. The study on these combination patterns is necessary. We recognize four palaeogeomorphology unit patterns of Qikou sag in the first member of Shahejie: uplift-gentle slope, more fault zone, paleoslop break-sag combination pattern, sag- large break groove-sag combination pattern, heave-fracture groove-drop-off paleoslop break-sag combination pattern and under-water lower uplift-biological reef flat combination pattern.