Abstract:

On the basis of the comprehensive analyses of the depositional sequence of the CretaceousNeogene outcrop sections, and the seismic sequence and drillhole information in Tarim Basin, the authors hold that the CretaceousNeogene strata can be divided into 32 depositional sequences in the southwestern depression and 27 depositional sequences in the northwestern depression. According to the study of ordered stacking of several 3rdorder sequences and tectonic sequences, 4 tectonic sequence interfacies with the form of unconformity can be identified in Tarim Basin. And the CretaceousNeogene strata may be redivided into 4 supersequences(SS14) which can be correlated synchronously in Tarim Basin, and the supersequence stratigraphic framework of the CretaceousNeogene in Tarim Basin can be established. Each supersequence represented the evolution cycle from progradation to retrogradation of 3rdorder sequence group and possesses the different characteristics of sequence association in different directions. The analysis of tectonic subsidence and depositional provenances indicate that the processes of subsidence and deposition in the depression in front of Tianshan and Kunlunshan Mts. possess the characteristics of subsection and double provenances of foreland basin: Middle subsidence in the Early Cretaceous, slow subsidence in the Late Cretaceous and rapid subsidence in the Paleogence and Neogence. The change of the provenance areas is recycled orogeninner cratonrecycled orogen. And at the same time, the subarea occurred in terms of sequence constitution, depositional speed and depositional system collocation along the orogen due to the difference in the impact of tectonic movements to the provenance area, which was stronger in the western area than in the east. This proves the characteristics of the basinorogene coupling evolution between the depositional filling of southwestern depression and northwestern depression and liftingfall process of Tianshan and Kunlunshan orogens.

Key words: Tarim Basin, sequence stratigraphic response, basinorogene coupling process, CretaceousNeogene