苏北-南黄海盆地的构造演化分析

Analysis on Structural Evolution of Northern Jiangsu-South Yellow Sea Basin

通过苏北-南黄海盆地的拉张率和沉降率等的分析认为,苏北-南黄海盆地的构造演化主要分为3个阶段。K2t-E1f沉积时期是苏北-南黄海盆地发育的兴盛期,这一时期盆地的拉张率最大,沉积速率也最大,吴堡运动剥蚀强度具有东强西弱的特点。E2d-E2s沉积时期为典型断陷盆地发育期,这一时期的盆地的拉张率和沉降率一般都小于前一时期。三垛运动使得凹陷保存地层较全,凸起、斜坡保存地层较少;南坳地层剥蚀少,北坳地层剥蚀多;三垛运动后,盆地由断陷转为拗陷,早期分割的断陷沉积转为统一的拗陷沉积。

By analysis of extension-ratio and subside ratio of northern Jiangsu-South Yellow Sea Basin,tectonic evolution of the basin was divided into three periods.The period of deposition of Taizhou-Funing Formation was a prosperous period of the basin development,in which the extensional ratio and deposition ratio of the basin were maximum.The erosion intensity of Wubao Event was stronger in the east and weaker in the west.The period of the deposition of Dainan-Sanduo Formation was a typical development period of a rift basin,of which extensional ratios and depositional ratios were lower than that of the previous period.For the effect of the Sanduo event,from the analysis of its preservation state,integrated strata were preserved in the depression and they were less preserved in humped and slope areas,and it was less eroded in the south depression and more in the north depression.After Sanduo event,the basin is turned from rift basin to depression basin,the earlier separated sediment of the rift basin is turned to a unified sediment of depression deposit