层序地层学在泌阳断陷湖盆中的应用──以双河—赵凹地区下第三系核三~上段为例

根据陆相地层层序在地震剖面、电测曲线上的识别标志以及在岩石类型和矿物成分上的特征，将泌阳断陷双河—赵凹地区下第三系核三上段划分为三个Ⅱ型层序，由南往北呈现冲积扇—扇三角洲—湖泊—三角洲的沉积体系空间配置。泌阳断陷陆相地层层序的体系域具有四分性，其准层序组类型有四种：低位加积型、退积型、高位加积到和进积型。在综合利用研究区钻井、测井及地质资料的基础上，根据下第三系核三上段地震相平面展布特征，将地震相转换为沉积相，并由此归纳出研究区核三上段的沉积模式。针对研究区目的层段所划分三个陆相层序发育的共同特点，建立了泌阳断陷湖盆陆相层序地层岩相格架模式；在连井剖面展序地层对比的基础上，编制了研究区目的层段的年代层序地层框架模式。

Application of sequence stratigraphy in Biyang fault basin-An application example of the upper Hesan member of Paleogene system in Shuanghe-Zhaoao area

According to not only the lithologic-mineral characteristics but also the identi-fication signs of land-facies sequence in seismic section and electric logs, the upperHesan member of Paleogene system in Shuanghe-Zhaoao area in Biyang fault basincan be divided into three secondary-type sequences ; and spatially, there are follow-ing sedimentary series from south to north in this basin: alluvial fan, fan delta,lake sediments and delta. Thus there exist four depositional system tracts of land-facies sequence in Biyang fault basin, therefore forming four subsequences whichare lowstand aggradation, regressive deposition, highstand aggradation and ingres-sion deposition. Having analysed the seismic facies lateral characteristics of Hesanmember of Paleogene system, with a good use of drilling,log and geology data inthis area, we converted its seismic facies into relevant sedimentary facies, fromwhich the depositional model of Hesan member in this area was derived desirably.A lithofacies frame model of land facies formation in the Biyang basin was made interms of the common development characteristics of three land-facies sequences ofthe interested object interval. Then, an age stratigraphic frame model of object in-terval was obtained by doing sequence correlation of seismic section that goesthrough boreholes.