Abstract:The marine carbonate layers of the upper Sinian is one of the potential target types for deep and ultra-deep oil and gas exploration in Tarim basin. However, evolution of the Neoproterozoic prototype basin and the distribution of source rocks remain controversial or unconfirmed. Combined with the joint inversion of gravity, aeromagnetic and electric data, the seismic interpretation of horizons and faults were conducted to depict the framework of uplift and depression in Tarim basin from Nanhua to Sinian period. The Neoproterozoic strata were expected to be well developed in the deep of Southwest Tarim and Awati depression by the evidences from geophysical anomaly and joint inversion of non-seismic data. Furthermore, the seismic interpretation indicated that the Neoproterozoic depressions distributed around the inherited Precambrian basement paleo-uplifts, with the northern subsidence zone and the southwestern Tarim subsidence zone were dominated by the NWW stretched rifts. The rifts were characterized by lower faulted-down depression and upper intracratonic sag vertically, with large-scale horsts and grabens laterally. The formation and distribution of Neoproterozoic rift basins in Tarim were genetic close related to lithofacies composition and fault system in basement. From rift basin in Nanhua to intracratonic sag in Sinian, the sedimentary deposits in Tarim changed from clastic rocks to carbonites. The Keping Movement occurred at the end of Sinian resulted in an ephemeral crustal uplift and sedimentation ceases, with the denudation in South Tarim is stronger than North Tarim. Those scattered rifting subsidence centers formed in Nanhua gradually contracted into relative widely spread hydrocarbon generation depressions in early Sinian, and the deepwater facies for source rocks deposition became migration to the continental margin of Tarim in late Sinian. Precambrian source rocks were assumed to develop in the paleo-rifts in deep of southwest tarim, and the effective coordination between the Paleo-rifts and Paleo-uplifts were the key issue for the oil and gas exploration of dolomite rocks under Cambrian salt. The large-scale carbonate reservoirs formed in the reefs and shoals in platform margin, and epiphytic karst in the upper Sinian were important target types.