1. Faculty of Resources,China University of Geosciences Wuhan),Wuhan City Hubei Province,430074,China;
2. Education Ministry Key Lab of Tectonics and Petroleum Resources,China University of Geosciences (Wuhan)
Abstract：In this paper the evolution and it's influence factor for the carbonate platform of Triassic Feixianguan Formation in Yuanba Area,Northeast Sichuan Basin was studied in the sequence framework.The Feixianguan Formation in Yuanba Area was divided into 2 third-order sequences,and 4 systems tracts.The Feixianguan Formation carbonate platform in Yuanba Area were affected by tectonic uplift and highstand shedding in different periods and different regions.In sequence SQ1 marine transgressive period,the north of the Yuanba area was affected by tectonic uplift,the lateral sediment thickness of the outer gentle slope is greater than the medial sediment's thickness of the outer gentle slope.The tectonic uplift from sequence SQ1 marine transgressive period to tectonic uplift in initial stage of high elevation period decreases the difference between the gentle slope on platform and the outer gentle slope,resulting in rapid expansion of the platform to the north.In sequence SQ1 high elevation period,the highstand shedding phenomena was remarkable in East of Yuanba Area.For high elevation period the accommodation for platform decreases,limiting vertical thicking potential for the platform,the sediment progrades laterally towards outer gentle slope,and the highstand shedding appears.The oolite beach mainly develops inside the slightly gentle slope and gentle slope which were formed in different stages of highstand shedding.
