四川磨溪-龙女寺构造香溪群高分辨率层序地层分析

The high-resolution sequence stratigraphy analysis of the Upper Triassic Xiangxi Formation in the Moxi-Longnusi structure of Sichuan,China

四川中部磨溪—龙女寺构造上三叠统香溪群发育一套河流相沉积,运用P.R.Vail(1987)源于被动大陆边缘的经典层序地层学理论加以描述已不完全适用。作者采用A.T.Cross倡导的高分辨率层序地层学方法,通过基准面旋回结构和叠加样式的沉积动力学分析,采用基准面旋回级次划分方案,对川中地区磨溪-龙女寺构造上三叠统香溪群进行了详尽的高分辨率层序地层分析。运用岩性剖面识别和测井剖面识别方法,在香溪群地层中识别出三种具有不同成因、发育规模和识别标志的基准面旋回类型。由此力求建立适合于河流相沉积的高分辨率层序地层学层序划分方案、旋回结构及叠加样式,并将其进一步运用到河流相沉积体系的砂体时空展布的研究中。

The sedimentary system of the Moxi-Longnusi structure is regarded as a river facies in central Sichuan basin in the Upper Triassic Xiangxi Formation. The classical sequence stratigraphy theory by P. R. Vail（1987）is unable to describe it. So the authors try to analyse it by the analytical technology of the high-resolution sequence stratigraphy. According to the sedimentary dynamic analysis of the sequence structure and stacking pattern and classification of the base-level cycle, an analysis of the high-resolution sequence stratigraphy is done to the Xiangxi Formation. Three types of base-level cycles with different contributing factors, genetic features, development scales and identification marks are distinguished by some marks of rock section and logging section. The authors try to research the classification, sequence structure and stacking pattern of the high-resolution sequence stratigraphy about river facies and further use them to study sand distribution.