小尺度的碳酸盐岩层序地层学分析--塔里木盆地桑塔木断垒带奥陶系层序地层学研究

层序地层学理论现已日臻完善，位人们往往被局限在大范围、大尺度的研究领域中，包括整个盆地或整个陆架的粗线条描述。那么，小尺度（小范围和次级层序）内的层序格式和沉积样式又是如何的呢？本文将作一阐述。在地层学、沉积学的研究基础上，在区域层序地层学的框架下，将桑塔木断垒带这样一个盆地内的三级局部构造的奥陶系进行层序地层学解剖。由于地震资料分辨率的限制，采用大量的钻井录井资料（岩心、电测等），通过岩性、古生物等特征标志建立相对水深变化曲线，以此来对比划分层序。得出，奥陶系内存在一个Ⅰ类层序界面，并将其划分为两个四级层序及相应的五级层序。

The Small Scale Sequence Stratigraphy of The Ordovician Carbonate of the Sangtamu Horst in The Tarim Basin

In this paper, the small scale Ordovician carbonate sequence stratigraphy was discussed based on theanalysis of stratigraphy and sedimentology of the Sangtamu horst Block which belongs to the first gradetectonic unit-- Tabei Rise Belt in Tarim Basin.The small scale means the local structure of the studedarea and the subordinate sequence of the studied range are relatively small.A large amount of laata, such as olgging, core, outcrop and paleontology, was utilized to constructvariation curve of relative water depth under the circumstance of the vestrict of the seismic resolution.The conclusions were as belows: ① The open platform-edge sedimentary system includes ten sedimentarytypes: algal lagoon, algal flat, oolitic shoal and so on.② The Ordovician system is classified into twofourthorder sequences in TypeⅠ sequence boundary and the corresponding fifth-order dequences are alsoclassified.③ The highstand systems tract is the best reservoir belt witout considering the anadiagenesisfactor.This snalysis made it possible to recognize the evolution of strata and facies in local structure and toforecast the distribution tendency of the reservoir.The achivenent of this study can be applied in theanalogy of other similar structures.