关键词: 塔里木盆地, 层序地层学, 沉积体系, 海退体系域, 沉积模式, 油气聚集

Abstract: The interaction of tectonics,change of global sea level and climate controlled the sediment supply and the scale of filled accommodation.On the ramp margin of forced regressive background,no by-pass sediments were migrated to basin floor during falling of the relative sea level.However there was a set of descending stepwise wedges known as forced regressive systems tracts in the basin.Donghe sandstone equivalent of Manxi Block in Tarim Basin was distinguished on the sequence boundary (unconformity),and it has shown iso-chronology and changes of lithological and litho-facies in the different places.The sequence SQ1 of Donghe sandstone equivalent was resulted from long-term falling of sea level and reinforced by tectonics.It shows a broadly developed basin-scale unconformity.The development of SQ1 was controlled distinctly by sea level changes.The marine ingressive systems tract was developed during fast rising period of sea level,and the forced regressive systems tract was developed during slow falling of sea level.Donghe sandstone of Manxi Block characterized by forced regressive systems tract was the composite sandstone body on the background of marine regression.The composite sandstone bodies were distributed in very complicated shapes,and most of them were developed in point-shape or cake-shape bodies.The oil-target reservoirs of the sandstone body were mainly distributed on the coastal zone and belonged to the shore face sediments.

Key words: Tarim Basin, sequence stratigraphy, depositional system, regressive systems tract, depositional model, hydrocarbon accumulation