高邮凹陷北斜坡戴二段辫状河三角洲沉积特征和演化

摘要

以岩心、录井、测井、分析化验和地震资料为基础，结合区域地质背景，对高邮凹陷北斜坡戴二段沉积相类型、展布及其演化规律进行研究。在总结、比较各类型三角洲特征的前提下，认定北斜坡戴二段主要发育辫状河三角洲相，局部发育曲流河三角洲和湖泊相。在此基础上，重点对戴二段辫状河三角洲各亚相、微相进行分析，划分出辫状河三角洲平原、辫状河三角洲前缘和前辫状河三角洲亚相，并针对各亚相对其包含的微相进行进一步划分。在综合考虑目标区域沉积背景和沉积特征的基础上，对沉积相展布和演化进行分析，并对辫状河三角洲形成机理进行了探讨。%In the light of core examination,well logs,laboratory data and seismic data,the type,distribution and evolution of sedimentary facies are dealt with for the braided delta deposits in the second member of the Dainan Formation in northern Gaoyou depression,Jiangsu. The second member of the Dainan Formation is dominated by the braided delta facies,followed by the meandering and lake facies. The braided delta facies in the study area may be subdivided into the delta plain subfacies including the braided channel and overbank microfacies,delta front subfacies including the subaqueous distributary channel,subaqueous interdistributary bay,channel mouth bar, distal bar and sheet sands microfacies,and prodelta subfacies including the prodelta mud microfacies. The distribution and evolution of the sedimentary facies and genetic mechanism of the braided delta are examined in detail in this study.