SEQUENCE FILLING DYNAMIC PROCESS OF EARLY-MIDDLE JURASSIC IN CENTRAL-SOUTH ORDOS BASIN

In order to undesstand the sedimentary features of the Ordos Basin in Early-Middle Jurassic, the principles and methodologies of base-level cycle analysis are used to study in detail the Early-Middle Jurassic base-level cycles of different orders in this basin. A high resolution sequence stratigraphic framework is established for the Fuxian Formation-Yan'an Formation in the Ordos Basin, and 4 long-term and 10 medium-term base-level cycles are identified. In view of the characteristics of sedimentary facies in this basin, this paper discusses the sequence filling dynamic processes of fluvial and delta depositional systems, presents the distribution pattern of base-level cycle superimposition styles in different facies belts, and studies the evolutionary history of sedimentary filling in combination with high resolution sequence division.