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呈“上张下压”结构的南鄱阳叠合盆地，K₂—E含膏泥岩区域盖层构筑了晚期的整体封闭保存体系，以P₁m、P₂l、T₃a 为主体的海相烃源岩具备晚期生烃潜力和油气运聚成藏条件，造就了海相烃源沉积重建型含油气保存单元并可细分出7个含油气保存单元。通过油气成藏因素系统解剖，认为存在古生古储、古生新储两种油气成藏类型，输导体系直接影响油气成藏，以小型—微小型油气藏为主，P₂l砂岩、P₂ch灰岩、T₃a砂岩和白垩系底砾岩是油气主要赋存目的层系。江埠—二甲村、向塘—前坊含保存单元勘探前景较好（Ⅱ_B），值得加快浅层海相烃源油气藏探索步伐，位于余干北—鸣山西的对冲前缘构造带是浅层油气藏的现实勘探区带。

Hydrocarbon-bearing Preservation Unit in Marine Facies Source Rocks in South Poyang Superposition Basin and Its Evaluation

In South Poyang Superposition (up extensional and down compressional) Basin,a late integral seal preservation system was constructed by the regional cap formation of K2—E gypsum bearing mudstones,and the marine facies hydrocarbon source rocks of P1m,P2l and T3a were of late hydrocarbon generation potential and oil/gas migration,accumulation and reservoiring conditions,thus causing the hydrocarbon bearing preservation unit′s being formed in marine facies source rocks,It may be subdivided into seven subunits.Through analyzing systematically the factors of reservoir formation,it was thought that there are two types of oil/gas reservoirs,i.e.“old bed generating and old bed storing” and “old bed generating and new bed storing” reservoirs;reservoir formation was directly influenced by transport system;oil/gas reservoirs are mainly composed of small and micro size ones;and the P2l sandstones,P2ch limestones,T3a sandstones and Cretaceous bottom conglomerates are the major target zones of oil/gas occurrence.The prospect of exploring for the hydrocarbon bearing preservation unit at Jiangbu—Erjiacun and Xiangtang—Qianfang is good and it is worthy to speed up the steps of exploring for the oil/gas reservoirs in shallow marine hydrocarbon source rocks.The ramp front structural belt being located at North Yugan—West Mingshan is the realistic area of exploring for the shallow oil/gas reservoirs.