伊通盆地鹿乡断陷始新统双阳组沉积相与沉积演化

Sedimentary facies and evolution of Eocene Shuangyang Formation in Luxiang fault depression of Yitong Basin

经岩芯观察,录井、测井资料分析,结合地震反演及粒度分析等方法,编制出伊通地堑鹿乡断陷星27井区始新统双阳组各段的砂岩等厚和地层厚度等单因素图件。采用单因素分析、多因素综合作图法,系统研究了双阳组的沉积特征及沉积演化规律。研究区双阳组主要发育扇三角洲、水下扇和湖泊沉积体系,并可进一步识别出9种亚相、13种微相。其中,双一段以湖泊沉积体系为主;双二段以扇三角洲沉积体系和水下扇沉积体系为主;双三段以湖泊沉积体系为主,水下扇不发育。双阳组沉积时期,构成了一套完整旋回,双一段和双二段下部为进积过程,双二段上部和双三段为退积过程。

Single factor maps including of sand-thickness and strata-thickness in each member of Shuangyang Formation in Well Xing 27 of Luxiang fault depression in Yitong graben are compiled through core observation and logging analysis combined with seismic inversion and grain size analysis.The authors systemically studied the sedimentary characteristics and evolutionary regulation of Shuangyang Formation with single factor analysis and multivariate integrated mapping.In the Shuangyang Formation,mainly developed the fan delta,subaqueous fan and lacustrine sedimentary systems,and 9 subfacies with 13 micro-facies can be recognized.The Member 1 of Shuangyang Formation is dominant by lacustrine sedimentary system;the Member 2 of Shuangyang Formation is dominant by fan delta and subaqueous fan sedimentary system;the Member 3 is dominant by lacustrine sedimentary system,with no development in subaqueous fan.A set of complete sedimentary cycle is made up during the deposits of the Shuangyang Formation,and appearing progradation from the Member 1 to the lower part of the Member 2 and retrogradation from the higher part of the Member 2 to the Member 3.