济阳坳陷古生界层序地层研究

运用层序地层理论与基准面旋回分析方法,结合钻井、地震、测井方法,将济阳坳陷古生界划分为3个超层序、14个三级层序,即馒头组-亮甲山组超层序A、下马家沟组-八陡组超层序B和本溪组-石千峰组超层序C。根据层序在区域地震剖面上标定结果,追踪解释4个超层序界面,建立了济阳坳陷古生界等时地层格架。测井约束反演剖面上,超层序显示清楚,自下而上呈现低阻抗、高阻抗、低阻抗三分现象。层序界面的主要识别标志有不整合面、岩电性突变面、河流冲刷面、颜色突变面,其中不整合界面为超层序分界面,其余可作为三级层序的分界面。在此基础上,确立了济阳坳陷地震层序的划分标准,建立了济阳坳陷古生界层序地层沉积模式。

Study of Paleozoic sequence stratigraphy in Jiyang depression

The Paleozoic in Jiyang depression can be divided into three super-sequences and 14 third-order sequences by using sequence stratigraphy theory and cycle analysis of datum level,combining with drilling, seismic and logging methods. The super-sequences are the Mantou formation-Liangjiashan formation (A), the Xiamajiagou formation-Badou formation (B) and the Benxi formation-Shiqianfeng formation (C). According to calibration of sequences in regional seismic profiles, an isochronic framework of the Paleozoic sequence stratigraphy in Jiyang depression is established through tracing and interpreting the four super-sequence boundaries. The three super-sequences are clear in logging-constrained inverse profiles, showing low, high and low impedances from bottom to top,respectively. The main identification marks of sequence boundaries are unconformable surfaces, scouring surfaces of rivers, surfaces showing abrupt changes of litho-electric properties and color, of which unconformable surfaces are super-sequence boundaries, while others are boundaries of third-order sequences. Standards for dividing seismic sequences are defined and a sedimentation model is developed for the Paleozoic sequence stratigraphy in Jiyang depression