【摘要】 物源分析是盆地分析的重要内容之一.北塘凹陷古近系沙河街组三段(Es3)湖泊范围广、沉积厚度大,而勘探程度低,是大港油田未来勘探的重要突破区,精细刻画北塘凹陷沙三段物源体系对沉积体系重建、有利区带预测具有重要意义.采用构造格架及古地貌宏观区分物源区与沉积区,根据碎屑矿物组合特征划分物源区块,依据地震反射特征勾绘物源在盆内进积方向,利用砂体等厚图和砂地比等值线图精细描绘物源分支,从不同角度、不同层次对北塘凹陷沙三段古物源体系进行精细研究.结果表明,北塘凹陷物源来自北部燕山褶皱带和西部沧县隆起,具体分为西部的沧县物源、西北角的汉沽物源、北部的大神堂物源和东北角的涧南物源.在物源体系和构造组合特征的控制下,沙三段主要发育扇三角洲沉积体系.更多还原

【Abstract】 Provenance analysis is an important aspect of basin analysis. Beitang sag is an important breakthrough zone for future exploration in Dagang oilfield with its wide range of lake,deep sediment thickness,and low level of exploration of the third member of Shahejie Formation (Es3). Detailed depiction of the provenance system using of Es3 is of practical significance for reconstructing depositional system and forecasting favorable areas. This paper analyzes in detail the provenance system of Es3 in Beitang sag from various angles and levels:the source area and the deposition area is macroscopically distinguished according to tectonic framework and palaeogeomorphology; the source block is determined according to the characteristics of detrital mineral assemblage; the direction of transporting clastic fragmen in the basin is described according to seismic reflection characteristics; and the source branches are finely pictured according to sandstone thickness distribution map and percent distribution map The research results show that provenances originated from Yanshan fold belt and Cangxian uplift. They are divided into western Cangxian source,north-west Hangu source,north Dashentang source and north-east Jiannan source. In the tectonic framework and the provenance system,there mainly developed fan-delta depositional system of Es3 in Beitang sag.更多还原