高邮凹陷吴堡断裂带南段古近系剥蚀量计算及地质意义

利用镜质体反射率最高古地温法和泥岩声波时差作图法对高邮凹陷吴堡—博镇断裂带上、下盘地层剥蚀量进行了计算,恢复了三垛期末的古地形,建立了埋藏史和热史。研究表明,断层下盘地层剥蚀量为1 400~1 700 m,上盘为800~1 100 m.上盘阜二段、阜四段烃源岩分别在戴南组沉积晚期、三垛组沉积早中期进入生烃门限,之后大量成熟生烃;下盘泰二段烃源岩在三垛组沉积早中期也达到生烃门限,但由于后期埋藏浅,仅处于未成熟或低成熟状态。

Recovery and Geologic Significance of Paleogene Eroded Thickness in South of Wubao Fault Zone in Gaoyou Sag

This paper recovered the paleotopography of late Sanduo,establishes the burial history and thermal history by using the highest paleotemperature method of vitrinite reflectance and the mapping method of mudstone acoustic time difference to estimate the eroded thickness on hanging wall and footwall in Wubao-Bozhen fault zone in Gaoyou sag.The results show that the eroded thickness on footwall is 1 400~1 700 m,and that on hanging wall is 800~1 100 m;the higher the paleotopography,the larger the eroded thickness.The source rocks in No.2 member and No.4 member of Funing formation on hanging wall has reached the oil threshold,respectively,in late Dainan formation and early-middle Sanduo formation,after that,a great amount of which are matured and generate hydrocarbon;the source rocks of No.2 member of Taizhou formation on footwall reach the oil threshold in early-middle Sanduo formation,but they are still in immature or low-mature state for shallow burial conditions in late period.