【作者】 冯镜权；

【导师】 李勇；

【作者基本信息】 成都理工大学 ， 沉积学， 2010， 硕士

【摘要】 孔南地区位于黄骅坳陷南缘,区内孔店组顶底均为不整合面,垂向上发育一个完整的沉积旋回,具有独立的成盆过程。该区古近纪孔店组沉积相类型多样,存在多个物源,前期研究工作缺乏系统性的物源分析。物源、成因砂体时空展布与隆起区之间的匹配关系对盆地分析、古地理恢复及区内隐蔽油气藏勘探具有重要意义,本文以该地区古近系孔店组为目的层位,以层序地层单元为基本单元,分析物源区特征和古水系类型、沉积体系特点,进而揭示孔店期盆地的物源体系与古地理特征。根据研究区盆地沉积古地貌特征以及构造、气候、沉积物供给和湖平面升降等层序发育控制因素,利用地震剖面、岩电剖面上识别的不同级别界面,将区内孔店组划分为1个二级层序和4个三级层序,并建立了以三级层序为基本单元的区域层序地层格架。利用砾石成分、砂岩骨架成分和重矿物分析来确定各层序物源区及其母岩性质、物源方向;根据重力异常特征、砾岩层厚度平面变化特征、砂体分散体系分析、地震剖面的反射结构及地震属性特征分析,认为区内存在沧县隆起、埕宁隆起、徐黑凸起、东光凸起、孔店凸起等五大剥蚀区,在盆地边缘发育自来屯-军马站-枣园、薛官屯-沧州、舍女寺-捷地、店子街-南皮、东光、灯明寺、乌马营、集北头、王官屯-东关、故县等10个物源口,发育横向水系和纵向水系两种水系类型;根据盆地周缘古陆的地层分布、岩性组成,确定各隆起剥蚀区与不同时期多个物源区之间的匹配关系;根据Dickinson三角图解判定物源区构造背景主要为大陆板块和岩浆弧区。在物源分析的基础上,结合沉积体系发育特征,探讨孔店期(SQ1～SQ4)的古地理特征。表现为:在气候上,从亚热带半干旱气候—温暖湿润—半干旱炎热—干旱气候;在构造上,经历了初始断陷—扩展深陷—稳定发展—断陷、沉积充填4个阶段;湖泊发育由零散分布封闭小湖泊—总体为湖泊—分隔小湖泊—膏盐湖;水系类型由以横向水系发育为主到纵向水系发育;沉积体系发育特征上,由冲积扇、三角洲沉积体系发育为主—三角洲、浊积扇沉积体系—冲积扇沉积体为主—冲积扇、扇三角洲和膏盐湖沉积体系。更多还原

【Abstract】 In south Kongdian area of the Huanghua depression, Bohai Gulf, the top and the bottom boundaries of Kongdian formation are the unconformity. With the vertical development of a complete sedimentary cycle, it has undergone an independent process of basining. The types of sedimentary facies are variety. There are several provenances. The research on provenance analysis of Kongdian formation was unsystematic in the earlier days. Provenance analysis, which includes the matching relationship between spatial distribution of the genetic sand body and uplifted area, is the important territory that rebuilding basin sense of palaeogeo graphical environment, analyzing basin and surveying subtle reservoir exploration. It has the important sense of direction and practice. It has the important sense of direction and practice. the paper chooses Kongdian formation of palaeogene in the south of Kongdian area as a research aid. Guided by the theory of nonmarine sequence stratigraphy, the author uses sequence section of reservoir as the elementary cell to analysis the character of provenance, the types of palaeodrainage pattern and sedimentary system, and then to reveal the provenance characteristics and palaeogeo graphical evolution characteristics of Kongdian formation in the south of Huanghua depression.According to the characteristics of the sedimentary basin palaeogeomorphology and controlling factors of sequences, such as structure, climate, sediment supply and lake-level fluctuation, and so on. Utilizing and realizing the different bounding surfaces on seismic cross-section and borehole log, it divides kongdian formation of palaeogene into one second-order sequence, and four third-order sequences. It uses third-order sequence as the base unit to build the sequence stratigraphic framework of the region. Utilizing conventional analytical methods, which include Gravel composition, Sandstone framework composition, Heavy mineral analysis, and so on, can identify the character of parent rock and the wards of provenances. according to contoured gravity anomaly map, thickness contour of Conglomerate, sand body disperse system, the reflection configuration of seismic and seismic attribution technique, it indicated that there are five major erosion areas, which are corresponding to Cangxian uplift, Chengning uplift, Xuhei bulge, Dongguang bulge and Kongdian bulge. The research indicate there are ten major source port in the edge of the basin, which are corresponding to Zilaitun– Junmazhan - Zaoyuan, Xueguantun - Cangzhou, Shenusi - Jiedi, Dianzijie - Nanpi, Dongguang, Dengmingsi, Wumaying, Jibeitou, Wangguantun - Dongguan, Guxian, etc. Cross channel and longitudinal drainage systems are developed around the basin. According to stratigraphic distribution and lithological composition of the palaeohigh,it can identify the matching relationship between several provenances and uplifted areas of each sequence. According to Dickinson’s trigonometric graphical methods, it can be judged that the tectonic setting typically belong to continental plate and magmatic arc zone.Based on provenance analysis and sedimentary system evolution characteristics, the paper probes into the Palaeogeographic evolution characteristics of each sequence. In summary, it is certain that: during SQ1 period, it was semiarid palaeoclimate of semi-tropical, and undergone fault sag evolutionary phases. There are several enclosed lakelet, and sediment provide basin system though river, which is main of cross channel. It developed delta depositional system and alluvial fan depositional system. During SQ2 period, it was humid climate in depression step. Main body of basin is lake, and mainly developed cross channel. It developed delta depositional system and turbidite fan depositional system. During SQ3 period, it was hot-semiarid climate in resistant step of fault sag. It developed several separate lake in the basin, and sediment was transported into basin though river, which is main of cross channel. It developed alluvial fan depositional system and delta depositional system. During SQ4 period, it was hot arid climate in fault depression step. The basin was distributed brackish-saltwater lake, and mainly developed longitudinal drainage system. It developed alluvial fan depositional system, fan delta depositional system and cream-salt deposit.更多还原