构造活动盆地的层序地层与构造地层分析--以中国中、新生代构造活动湖盆分析为例

中国中、新生代构造相对活动的断陷或陆内前陆盆地充填序列一般可划分出5个级别具有地层对比意义的层序地层单元。层序构成和沉积体系域的发育分布受到盆地形成演化过程中各种构造作用的控制。盆地规模的沉积旋回多是盆地幕式裂陷、多幕挤压挠曲沉降、多期构造反转、断块差异沉降等构造作用的沉积响应;高频层序单元的发育则主要与湖平面和沉积物供给量的变化有关。不同构造演化阶段的层序结构和沉积体系域构成等存在显著差异,主要取决于古构造格架和同沉积构造的活动。构造坡折带是由构造活动所产生的、对沉积作用具有长期控制作用的古沉积斜坡或古地貌突变带,在断陷或前陆等盆地中普遍发育,其识别对阐明盆内沉积体系域,特别是构成重要油气藏的低位域的分布和预测具有重要意义。

Sequence stratigraphy and tectono-stratigraphic analysis of tectonically active basins:A case study on the Cenozoic-Mesozoic lacustrine basins in China

Filling sections of Mesozoic-Cenozoic tectonically active basins in China can generally be divided into five ordered, correlatable sequence stratigraphic units. The sequence architecture and the distribution of depositional systems tracts were mainly controlled by a variety of tectonic activities during the formation and evolution of the basins. Depositional cycles on basin scale have been interpreted as the result of depositional response to tectonism such as episodic rifting, polyphasic compressive flexural subsidence and reversion, and differential subsidence of fault blocks; while the formation of high frequency sequences was attributed to variation in lake level and sediment supply. The sequence units formed in different evolutional stages of basin show significant difference in sequence architecture, in depositional systems tracts and in sedimentary disposal patterns, which were predominantly determined by the paleo-structural framework and the activation of syndepositional structures in the basins. The structural slope-break zones are defined as the depositional slopes abrupt change in geomorphology and developed widely in fault and foreland basins, the recognition of which is significant for predicting the distribution of depositional systems tracts, particularly the lowstand systems tracts which usually comprised economically important reservoirs in these basins.