塔里木盆地下古生界碳酸盐岩层序地层学研究

塔里木盆地下古生界寒武系－下奥陶统沉积横向上包括了台地至盆地型的碳酸盐岩沉积，厚约３０００－５０００ｍ．从地震反射上可划分为三个体系域；低水位期体系域为一套向东呈楔形发散的中振幅反射结构，分布范围仅在盆地的东北部，海进期体系域为一套的１００－１５０ｍｓ的中－强振幅高连续性反射，平面呈席状，在盆地的大范围分布，高水位期体系域为一套１ｓ厚的反射层，根据反射结构可进一步划保持型和追赶型两种碳酸盐岩体系，

Sequence stratigraphy analysis of carbonate series of Lower Palaeozoic group in the Talimu basin

In the Talimu basin, Cambrian-Lower Ordovician sedimentary series are 3000~5000m thick carbonate sedirnents which laterally range frorn platform facies to depression facies. 3 depositional system tracts can be distinguished in terms of seismic reflection configurations. The lowstand system tract leads to wedge tnid-amplitude reflection configuration diverging eastward, and exists in northeast part of the basin.The transgression system tract results in 100 ~ 150ms thick continuous reflection configuration having mid-high amp1itudes, and occurs in wide sheet distribution in the basin. The highstand system tract brings ls thick reflection configuration and can be subdivided into the keep-up and catch-up carbonate system tracts. The keepup carbonate system tract produces continuous low-frequency reflections in platorm, chaotic reflections and no ref1ection at platform margin, oblique progradational reflections on marginal slope of platform, and continuous mid-amplitude reflections in depression. The catch-up carbonate system tract brings weak reflections or no reflection, and its top boundary is a regional unconformity, namely type I sequence boundary. Industrial oil flows have been discovered in drillings on local structures in the top boundary. Lithofacies interpretation says that the favourable reservoir facies belts in Cambrian -Lower Ordovician sedimentary series lie in the marginal and foreslope facies areas of platform