Sequence stratigraphic features of the Cambrian carbonate rocks in the Tarim Basin

Sequence stratigraphic theories of carbonate are employed in a sequence stratigraphic study on the Lower Paleozoic carbonates in Tarim Basin through outcrop observation,drilling data analysis as well as integra-ted seismic interpretations.Together with the study,the sequence boundaries are identified and stratigraphic framework is established.As a result,eight sequences identified in the Cambrian carbonates are described.Except for sequence 1(SQ 1) as a ascending base level semi-cycle sequence,the other sequences are all falling base level semi-cycle sequences.Sequences 5,6,7 and 8 are considered key hydrocarbon exploration targets.In Lunnan area,exploration activities shall be focused on sequences 6,7 and 8 for complex structural-lithologic traps.A model for the Cambrian carbonate sequences in the Tarim Basin is developed and provides helpful aid to searching for places with favorable conditions for the formation of stratigraphic lithologic traps.