On the Carboniferous Sequence Stratigraphy in the Tazhong Area, Xinjiang——A Model of the Sequence Stratigraphy Framework of Intracratonic Depressional Basins

The Carboniferous prototype sedimentary basin in the Tazhong (Central Tarimbasin) area is recognized as a compressive intracratonic depressional one. Three type Ⅰ sequenceboundaries and three type Ⅱ sequence boundaries can be identified in the CarboniferousSystem, which can accordingly be divided into five sedimentary sequences. These sequencespossess stratigraphic characters of the standard sequence and correspond to the depositionalstratigraphic unit of a third-order eustatic cycle. They can be regionally or globally correlatedwith each other. The framework of sequence stratigraphy of the intracratonict basin in thestudy area distinctly differs from that of the passive continental-margin basin in the lack ofdepositional systems of early-middle lowstand, poor development of the deeply incised valleyand condensed section of the maximum sea-flood, good development of type Ⅱ sequenceboundaries and coastal plain depositional systems coexisting with shelf-type fan deltas underwet climatic conditions, Which consequently led to the formation of a paralic lithofacies frame-work.

On the Carboniferous Sequence Stratigraphy in the Tazhong Area,Xinjiang — A Model of the Sequence Stratigraphy Framework of Intracratonic Depressional Basins

The Carboniferous prototype sedimentary basin in the Tazhong (Central Tarim basin) area is recognized as a compressive intracratonic depressional one. Three type I sequence boundaries and three type II sequence boundaries can be identified in the Carboniferous System, which can accordingly be divided into five sedimentary sequences. These sequences possess stratigraphic characters of the standard sequence and correspond to the depositional stratigraphic unit of a third–order eustatic cycle. They can be regionally or globally correlated with each other. The framework of sequence stratigraphy of the intracratonict basin in the study area distinctly differs from that of the passive continental–margin basin in the lack of depositional systems of early–middle lowstand, poor development of the deeply incised valley and condensed section of the maximum sea—flood, good development of type II sequence boundaries and coastal plain depositional systems coexisting with shelf–type fan deltas under wet climatic conditions, which consequently led to the formation of a paralic lithofacies framework.