鄂尔多斯东南部上古生界层序地层特征  

Characteristic of Upper Paleozoic Sequence Stratigraphy in East-southern Ordos Basin

作　　者：于波 

机构地区：[1]陕西延长石油(集团)有限责任公司研究院,陕西西安710075

出　　处：《西北地质》2016年第1期92-100,共9页Northwestern Geology

基　　金：国家科技支撑计划项目(2012BAC26B00)

摘　　要：鄂尔多斯东南部上古生界可区分出的三级层序界面类型包括区域不整合、构造体制转化面、区域海退面、河道下切面、区域(暴露面)、煤层、灰岩底界与地层叠置样式转化面。基于层序界面特征分析,上古生界本澳组至石盒子组可划分为2个二级层序,其中本溪组、太原组和山西组为1个二级层序(SS1),石盒子组整体划归为1个二级层序(SS2)。每个二级层序由区域性的水进-水退旋回组成,为构造控制型层序。二级层序进一步划分为11个三级层序,即本溪组划分出2个三级层序(SQ1和SQ2)、太原组划分出1个三级层序(SQ3)、山西组划分出2个三级层序(SQ4和SQ5)、石盒子组划分出6个三级层序(SQ6-SQ11)。其中SQ1-SQ5为海相及海陆交互相沉积层序,SQ6-SQ11为陆相湖盆沉积层序。基于层序地层特征分析,建立了鄂尔多斯盆地东南部地区层序充填模式,对于沉积体系演化、气藏形成及聚集研究都具有指导性意义。In east-southern Ordos basin, the Styles of third-order sequence boundary in Upper Pa- leozoic strata within can be districted as seven styles, including regional unconformity, structural system transformation surface, regional regression surface, channel erosion surface, regional leakage surface, coal bed, overlay-style transformation surface between limestone bottom and strata. Based on the analysis of sequence boundary characteristic, the Paleozoic stratigraphy, from Benxi Formation to Shihezi Formation, can be divided into two second-order sequences, namely the one （SS1） includes Benxi Formation, Taiyuan Formation and Shanxi Formation, the other （SS2） includes Shihezi Formation. Every second-order sequence is dominated by tectonic, including regional transgression and regression cycles. The second-order sequence can be divided into 11 third-order sequences, that is two third-order sequences （SQ1 and SQ2） in Benxi Forma- tion, one （SQ3） in Taiyuan Formation, two （SQ4 and SQS） in Shanxi Formation, six （SQ6 and SQ11） in Shihezi Formation. In which, the sequences of SQ1-SQ5 are marine and marine-conti-nental sediments, while SQ6-SQll are lacustrine sediments on continental. With the characteris tic of sequence stratigraphy, the sequence-filling model in east-southern Ordos Basin has been es tablished in this paper, which has a guiding significance for further research in sedimentary sys tem evolution, reservoir formation and gathering for gas.

关 键 词：鄂尔多斯盆地 上古生界 层序地层 充填模式 

分 类 号：P535[天文地球—古生物学与地层学]