On the basis of drilling and 3D seismic data in the Baiyun Sag,Pearl River Mouth Basin,under the theoretical sequence stratigraphy,this article starts with the seismic sequence analysis.After synthesizing logging and paleontology data,the identification symbol of third-order sequence boundary is firstly determined by combination of overall and partial analysis.Then according to the inner sequence texture (such as progradation and retrogradation),system tract has been divided into three second-order sequence boundaries and five third-order sequence boundaries in Wenchang and Enping Formation of the eastern Baiyun Sag.Then third-order sequence stratigraphy framework of Wenchang and Enping Formation has been established.The WCSB4 is regarded as secondorder sequence boundary in the target area.Finally three basin margin settings (gentle slope step fault,fault controlled steep slop and flexure slop-break) and their corresponding sequence texture pattern have been smnmarized.%基于珠江口盆地白云凹陷的钻井和三维地震资料,以经典层序地层学理论为指导,从宏观地震层序分析入手,综合运用测井和古生物等资料,采取局部和整体相结合的方法,首先厘定了三级层序界面识别的标志,并结合前积、退积等内幕结构进行了体系域划分,在白云凹陷东部文昌-恩平组中识别出3个二级层序界面和5个三级层序界面,从而建立了研究区文昌组-恩平组的三级层序地层格架,并在研究区提出WCSB4为二级界面,最终总结归纳了缓坡断阶、断控陡坡和挠曲坡折3种盆缘背景,建立相应的层序结构模式.
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