渤中凹陷石臼坨凸起东部南缘沙河街组沉积相及控制因素

SEDIMENTARY FACIESES AND THEIR CONTROLLING FACTORS OF SHAHEJIE FORMATION IN THE SOUTH EDGE OF EAST SHIJIUTUO SALIENT OF BOZHONG SAG

利用地震、录井、测井、岩心等资料，对渤中凹陷石臼坨凸起东部南缘古近系沙河街组沉积相类型及展布进行了研究，并分析了沉积控制因素。古近系主要发育冲积扇、扇三角洲、辫状河三角洲、滩坝和湖泊等沉积相。孔店组＋沙四段沉积时期，发育冲积扇、扇三角洲和湖泊沉积，湖泊水体深度较浅，范围小；沙三段沉积时期，发育扇三角洲、辫状河三角洲和湖泊等沉积，水体深度增至最大，范围增加；沙一＋二段沉积时期，发育辫状河三角洲和湖泊沉积，水体深度再次变浅，范围最广。在渤中坳陷特定的古构造格局下，冲积扇沉积主要受古气候-物源-古地形变化组合因素的控制，扇三角洲和辫状河三角洲沉积主要受古气候-物源-古水系-古地形-湖平面变化组合因素的控制，滩坝沉积主要受古气候-物源-水下低隆起-湖平面变化组合因素的控制。

With the help of the seismic, mud logging, well logging, core data etc. , the studies of the sedimentary facies types and their spreads of Palaeogene Shahejie Formation in South Edge of East Shijiutuo Salient of Bozhong Sag are conducted, and moreover the controlling factors fan delta, braided river delta, beach bar and lake facies on the sedimentation are also analyzed. The alluvial fan, and so on are mainly developed in the Palaeogene system. In the sedimentary period of Kongdian Formation and Sha No. 4 Member, the alluvial fan, fan delta and lake facies were developed and characterized by shallow and small-size lake water; in the period of Sha No. 3 Member sedi- mentation, the sedimentations of fan delta, braided river delta, lake facieses and so forth were developed and featured by the increasing depth and up to the deepest scale, and furthermore the size was spread ; for the depositional period of Sha No. 1 and Sha No. 2 Member, the braided river delta and lake facies depositions were developed, the water of lake was once more become shallow, but the size was the biggest. In the particular ancient tectonic pattern of Bozhong Sag, the alluvial fan deposition is mainly controlled by the combination factor of the ancient climate- source material-ancient terrain change; the fan delta and braided river delta sedimentations are principally domina- ted by the combination factor of the ancient climate-source material-ancient river system-ancient terrain-the lake lev- el change; the beach-bar deposition is generally determined by the comprehensive factor of the ancient climate- source material-ancient underwater terrain-the lake level change.