轮古东地区石炭系巴楚组东河砂岩段-角砾岩段层序地层特征

Stratigraphic Sequence Characteristic of Carboniferous Donghe Sand-Stone and Briccia Section in Eastern Lungu Area,Tarim Basin

在精细的岩性岩相分析和井-震标定研究的基础上,应用沉积学和层序地层学的理论及方法,通过井间及区域连井对比,对轮古东地区石炭系巴楚组(C1b)东河砂岩段-角砾岩段层序地层特征进行了详细研究,建立东河砂岩段-角砾岩段四级准层序发育模式图。研究认为东河砂岩段-角砾岩段为石炭系下统三级层序(SQC1)中的一个四级准层序组(SQC1-1),包括了SQCd和SQCj两个准层序。SQCd准层序对应的岩性地层为东河砂岩段地层,属于在SB1不整合面上发育起来的海侵沉积层序,为海侵体系域的滨岸带海滩沉积;SQCj准层序对应的岩性地层为角砾岩段地层,是高位体系域的冲积扇-扇三角洲沉积产物,底界SB2层序界面为体系域转化界面而不是不整合面,其顶界面为一个海泛面。

Based on the refined analysis of lithology and petrographic,as well as the elaborate calibration of drill- seism,by the principle and method of sedimentlogy and Stratigraphic Sequence,contrasting drill- drill and drill- tie,the Stratigraphic Sequence Character of Carboniferous Donghe Sand- Stone and Briccia Section in Easter Lungu area were studied in detail,and the development model was built. The studies show that Donghe Sand- Stone and Briccia Section is a fourth parasequence formations（ SQC1- 1）which includes SQCd parasequence and SQCj parasequence. The lithostratigraphic corresponding with SQCd is Donghe Sand- Stone section,a transgressive sedimentary sequence which develops on the SB1 unconformity,as coastal beach sedimentary of transgressive systems tract. The lithostratigraphic corresponding with SQCd is Bricca section,which is alluvial fan- fan delta high sedimentary of high stand system. SB2 sequence boundary which under SQCj is not the unconformity but the transform boundary of sys-tem tract; and the upper boundary is maximum flooding surface.