渤海湾盆地歧口凹陷古近系沙一段物源—沉积体系重建  

Reconstruction of Provenance-Sedimentary System of the First Member of the Paleogene Shahejie Formation in the Qikou Sag,Bohai Bay Basin

作　　者：吕琳[1] 焦养泉[1,2] 吴立群[1] 鲁超[1] 荣辉[1] 汪小妹[1] 

机构地区：[1]中国地质大学资源学院,武汉430074 [2]中国地质大学构造与油气资源教育部重点实验室,武汉430074

出　　处：《沉积学报》2012年第4期629-638,共10页Acta Sedimentologica Sinica

基　　金：中国石油天然气股份有限公司重大专项课题(编号:2008E-0601)资助

摘　　要：采用布格重力异常手段宏观地区分物源区和沉积区,根据重矿物特征分析物源区位置及影响范围,依据地震反射特征识别物源运移方向,通过砂分散体系精细分析和表征物源—沉积体系特征,并利用岩石地球化学资料进一步佐证物源—沉积体系分析。综合研究表明,渤海湾盆地歧口凹陷沙一段时期存在五个物源区,分别为葛沽物源、小站物源、增福台物源、钱圈物源和北大港潜山物源。葛沽物源为板桥次凹提供沉积物,且沉积物主体呈两支向歧口主凹进一步推进;小站物源、增福台物源和钱圈物源影响范围较小,均呈两支进入板桥次凹;北大港潜山物源为歧北次凹提供沉积物,向马棚口和高尘头地区推进时物源频繁分叉。综合岩芯、录井、测井和古生物等沉积成因标志,认为板桥次凹发育扇三角洲沉积体系,歧口主凹和歧北次凹发育深湖浊流体系。Accoding to the characteristics of the Bouguer gravity anomalies,the source and deposition areas were macroscopically distinguished in this paper.Based on the characteristics of heavy mineral,the location and extent of the source areas were described.In addition,the direction of the sources were determined on the basis of seismic reflection characteristics.Furthermore,the characteristics of provenance-sedimentary system were finely pictured by the distribution of sandbody,and could be further verified through geochemical characteristics.Different ways exerted respective superiority,and various means revised each other,the provenance-sedimentary system of the first member of the Paleogene Shahejie Formation in the Qikou sag of the Bohai bay basin was reconstructed by these ways.The results suggested that,there were five sources in the first member of Shahejie Formation in the Qikou sag,that were Gegu source,Xiaozhan source,Zengfutai source,Qianquan source and Beidagang buried hill source.The Gegu source was the largest source in the Qikou sag,the direction was overall the northwest to southeast,it provided sediments for Banqiao sag,and the sediments were further promoted into Qikou sag mainly in two directions but terminated at the downthrow wall of the Qizhong fault,the migration direction of the source location evolved from the southwest to the northeast in the first member of the Shahejie Formation,but the scale of the migration is small.The Xiaozhan source developed along Xiaozhan to Baishuitou area,the extent was small,the sediments were promoted into Banqiao sag in SSE and SE,the migration direction of the source location evolved from northeast to southwest.The scale of the Zengfutai source was limited which was influenced by the Dazhangtuo fault,the sediments filled into the Banqiao sag,and the source location migrated along northeast.The location of the Qianquan source was unstable,the migration direction of the source location evolved from west to northeast,the extent of migration was large scale,the sedi

关 键 词：歧口凹陷 沙一段 物源—沉积体系 

分 类 号：TE121.3[石油与天然气工程—油气勘探]