渤海湾盆地东营凹陷古近系岩性圈闭分布规律

THE DISTRIBUTION OF LITHOLOGIC TRAPS OF EOGENE IN THE DONGYING SAG OF THE BOHAI BAY BASIN

张宇

Zhang Yu

中国科学院, 广州地球化学研究所, 广州, 510640 2. 中国石油化工股份有限公司, 胜利油田分公司, 山东, 东营, 257015

Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangdong 510640, China 2. Shengli Oilfield Company, SINOPEC, Dongying, Shandong 257015, China

渤海湾盆地东营凹陷古近系主要存在3种成因类型的岩性圈闭模式,其中与三角洲有关的浊积扇岩性圈闭受三角洲结构控制,与较大规模的湖泛作用有关,多发育在中期基准面上升半旋回;近岸水下扇—浊积扇岩性圈闭受古地貌、断裂性质、断裂活动强度与断裂组合样式等控制,多与沟谷地貌、断阶及断裂的持续活动密切相关;古地貌平台—滩坝岩性圈闭受物源、古地貌及湖岸线控制,主要位于在粗碎屑沉积体前方及侧翼的古地貌平台,发育于长期基准面上升期,其中坝砂主要形成于中期基准面下降期,滩砂主要形成于中期基准面上升期。

There are mainly three genetic types of lithologic trap mode in the Dongying Sag of the Bohai Bay Basin during Eogene time,which are turbidite(fan) trap related to delta,near-shore subaqueous fan-turbidite fan trap and palaeo-geomorphic platform beach-bar trap.Controlled by genetic types of delta,the turbidite(fan) traps are related to flood lakes.So they are often developed during rising hemicycle of medium-term base-level.Near-shore subaqueous fan-turbidite fan traps are controlled by the palaeo-geomorphology,the characteristics of the faults,the fracture intensity,fracture combination styles,etc.The development of the subaqueous fan is often closely related to trough-valley,fault order,continuous movement of the fault.Controlled by the provenance,palaeo-geomorphology and lake strandline,palaeo-geomorphic platform beach-bar traps lies on the palaeo-geomorphic platform in front of or beside the coarse grained lithosomic body,and develops the rising time of the long-term base-level.In the high-frequency sequence frame,bar sand mainly forms during fall time of the middle-term base-level,while beach sand mainly in rise time of the middle-term base-level.

https://doi.org/10.11781/sysydz200906583