陆内克拉通盆地层序地层构型及其控制因素

Sequence Stratigraphic Architectures of Intra-Cratonic Basin and Its Controlling Factors

通过总结我国鄂尔多斯盆地和澳大利亚Surat basin这两个典型的陆内克拉通盆地的层序充填序列,认为该类盆地具有典型的层序地层充填模式:(1)典型的正粒序岩性组合特征;(2)基准面旋回为上升半旋回为主的不对称旋回,具有长期持续水进、短期水退旋回特征;(3)层序主要以LST为主,发育相互切割叠置的复合砂体,为最有利储层;TST和HST相对不发育,发育孤立状的单砂体,为中-差储层.陆内克拉通盆地层序地层及其控制的砂体具有"溯源退积"的时空展布模式,该模式主要受到盆地边缘构造、沉积物供给、湖平面变化、古地形、"盆地充填"和气候等因素的单独或综合控制.

Our study on two typical intra-cratonic basins,namely,Ordos basin,China and Surat basin,Australia indicates that the sequence stratigraphic infilling succession is correlated,The study results show that intra-cratonic basin has unique stratigraphic infilling characteristics,such as（1） typical fining-upward lithology association successions with a sandstone-rich lower part and a mudstone-rich upper part;（2） asymmetrical base level cycle mainly composed of ascending half cycle,with the characteristic of long term transgression and short term regression;（3） sequence stratigraphy made up primarily of a lowstand system tract with multistorey stacked sandstones forming excellent reservoir quality,and little deposition of transgressive system tract and highstand systems tract with isolated sandstones within mud-dominated deposits forming medium or poor reservoir.The spatial and temporal distributions of sequence stratigraphy and sandstones in the intra-cratonic basin are characterized by the source-ward retrogradation controlled by structure action of basin margin,sediment supply,eustasy,palaeotopography,basin infilling,climate,or integrated influence of above-listed factors.