Abstract: Lower Ordovician caAonate in Tabei uplift can be distinctively divided into two types of facies belts: shallow-water caibonate plateform in the west and deep-water carbonate slope-basin in the east - The former is dominated by tidal flat facies, and the latter is obviously controlled by the tectonic setting of the passive continental margin at the eastern margin of Tarim massif. Carbonate sedimentary facies model correlates well with Tucker model. Lower Ordovician depositional cycles are abundant and regionally correlated indicating its dependence on sea-level change. Frequent short-time exposure at the top of the depositional cycle resulted in the formation of vugular-pore in carbonate deposits subjected to leaching and dissolution of meteoric fresh water. However, such pores were influnced and reworked in late diagenetic stage.

Key words: Tarim basin, Tabei uplift, Carbonate, Early, Ordovician, Deposional model, Depositional cycle, Sea level, Verticle movement