苏北盆地高邮凹陷古近系戴南组沉积相及沉积演化

根据岩心、电测曲线、录井以及地震资料，对苏北盆地高邮凹陷古近系戴南组的沉积相类型、展布特征及其演化规律进行了系统的研究。结果表明，戴南组发育扇三角洲、三角洲、近岸水下扇和湖泊四种沉积相类型，扇三角洲、近岸水下扇分布在凹陷南部陡坡，三角洲分布在北部缓坡，湖泊分布在凹陷的中心及扇三角洲、三角洲、近岸水下扇的侧翼，从凹陷边缘到中心，沉积相由扇三角洲、三角洲、近岸水下扇沉积逐渐变为滨浅湖、半深湖沉积，整体呈南北分异、隆凹成带的格局。戴南组的沉积演化可划分为戴南组一段和戴南组二段两个时期，不同时期的沉积特征、沉积相展布表现各异，总体表现出水体由浅变深，再变浅，沉积范围逐渐扩大，扇三角洲、三角洲、近岸水下扇先退积，后进积的特点。

Sedimentary Facies and Evolution of Paleogene Dainan Formation in Gaoyou Sag,Subei Basin

Based on a comprehensive analysis of core, logging data and seismic survey, the sedimentary facies types of Paleogene Dainan Formation, Gaoyou Sag, Subei Basin were studied systematically, as well as their distribution and evolution. The research showed that fan delta, delta, nearshore subaqueous fan and lacustrine facies deposited in the formation, of which fan delta and nearshore subaqueous fan located along the steep south border, delta in the gently north slope and lacustrine in the central zone of the deep area and the flank of the fan delta, delta and nearshore subaqueous fan. From the margin to the depocenter of the sag, the sedimentary environments gradually changed from fan delta, delta or nearshore subaqueous fan to shore shallow sediments and middle depth lacustrine. The palaeogeography of the Dainan Formation displayed a clear south north zonation. The sedimentary envolution of Dainan Formation was divided into two stages, in which the sedimentary characteristics and the sedimentary facies distribution were correspondingly different. As a whole, the depth of water changed from shallow to deep, and then to shallow, sedimentary area gradually enlarged, and fan delta, delta and nearshore subaqueous fan frist retrogradated, then progradated. 