Abstract:

Different orders of unconformities in North Tarim Basin are resulted from tectonic movement,stress field transformation and sea level changes.According to multi order unconformities in stratigraphic record,the sequences of Sinian Paleozoic in the study area could be distingushed into 3 megasequences,9 supersequence sets and 39 third order sequences.Though the sedimentary environment,typical featrues of system tracts and distribution regularities of the 3 megasequences are different,the superposition patterns of the third order suquences are basically the same,that is,aggradation,transgression,regression and onlap associations.Based on chronostratigraphic framework,the Sinian Paleozoic could be divided into 3 mega cycles of sedimention.The unconformities between the mega cycles controlled the transformation of depositional pattern.