松辽盆地彰武断陷九佛堂组地层对比与划分

The Correlation and Division of Jiufotang Formation Stratigraphic in Zhangwu Depression,Songliao Basin

彰武断陷整体为砂泥岩互层沉积,地层在地震剖面上反应为长轴、较连续、强振幅的反射特征,在区内广泛分布,受东部断层长期活动影响,厚度略有差异,表现为东南部厚,向西北减薄的特征。根据钻井资料、二维地震、结合沉积充填序列、古生物组合特征,将九佛堂组地层划分为七个砂组,Ⅰ、Ⅱ号砂组为半深-深湖相沉积,Ⅲ、Ⅳ、Ⅴ号砂组为扇三角洲沉积,Ⅵ、Ⅶ号砂组为冲积扇沉积。

The sedimentary of the overall Zhangwu Depression is sandstone and mudstone interbedded. The Stratigraphic response in the seismic profile is major axis, more continuous, high amplitude reflection characteristics. This phenomenon is widely distributed in the region. The difference of stratigraphic thick- ness is affected by the impact of long--term activities of the eastern fault. The characteristic of Strati- graphic is the southeastern thick, northwest thinning. According to drilling data, 2D seismic, combined with the sedimentary filling sequence, paleontological assemblage characteristics of Jiufotang stratum is di- vided into seven sand group. I, II sand group for a half deep -- deep lake facies, Parts III, IV, V sand group for the fan--delta deposition, VI, VII sand group is alluvial fan deposition.