鄂尔多斯盆地临兴地区上古生界层序地层格架及沉积模式

Sequence Stratigraphy Framework and Sedimentary Model of Upper Paleozoic in Linxing Area,Ordos Basin

通过分析岩心、钻测井及地震资料,建立了鄂尔多斯盆地临兴地区上古生界精细等时层序地层格架,将上古生界划分为5个二级层序、14个三级层序、38个四级层序以及65个五级层序。本溪、太原组海相三级层序发育海侵及高位体系域,缺失低位体系域;山西、石盒子及石千峰组海陆过渡相及陆相层序发育完整的低位、海侵和高位体系域。并初步形成了适用于临兴区块的小层划分标准。在层序格架内,通过识别相标志及测井相分析,沉积微相类型为潮道、砂坪、砂泥坪、泥灰坪、泥炭坪、潟湖、内陆棚泥、分流河道、(水下)分流河道、分流间湾、水下分流河道间、河口坝、远砂坝及滨浅湖泥14种类型。太原组发育海相障壁海岸潮坪—潟湖—浅海陆棚层序地层发育模式,石盒子组发育陆相湖泊—辫状河角洲层序地层发育模式。

Through the analysis of core,drilling and logging data,combined with seismic data,the fine isochronous sequence stratigraphic framework of the Upper Paleozoic has been established in the Ordos basin.The Upper Paleozoic is divided into five 2 nd sequences,fourteen 3 RT sequences,thirty-eight 4 th sequences and sixty-five 5 th sequences.The marine transgression and high level system tract of the marine facies of Benxi and Taiyuan formation is developed,and the low system tract is absent.The low position,transgression and high system tract of Shanxi,Shihezi and Shiqianfeng sea and land transitional facies and continental sequence are fully developed.The classification standard of small layer suitable for the Linxing Area is initially formed.In the sequence framework,the sedimentary microfacies developed in the study area are determined by identifying phase markers and logging facies analysis.There are 14 types of sedimentary microfacies:tidal channel,sand flat,sand mud flat,peat flat,peat flat,lagoon,inland shed mud,(underwater)distributary channel,underwater distributary channel,estuarine dam,far sand dam and shallow lake mud.Taiyuan formation developed marine barrier coastal tidal flat-lagoon-shallow sea shelf s sequence stratigraphic development model,the Shihezi formation developed continental lake-braided river delta sequence stratigraphic development model.