沉积盆地的构造地层分析——以中国构造活动盆地研究为例

Tectono-Stratigraphic Analysis of Sedimentary Basins: A Case Study on the Inland Tectonically Active Basins in China

结合盆地形成演化过程中各种构造作用与盆地沉积充填和改造过程的成因分析,是揭示内陆构造活动盆地沉积体系域时空配置和生储盖发育分布的重要基础。各级构造不整合面的发育分布决定着盆地规模等时地层格架的基本样式。盆地构造演化的阶段性、旋回性及多期的构造变革对盆内多旋回的沉积—剥蚀过程的叠加和原型盆地的叠合等可产生深刻的影响。阐明不同构造幕同沉积构造活动和古构造格架与沉积物分散过程和构造古地貌变化的成因关系,是建立盆地沉积充填模式的关键。构造坡折带对特定的沉积相带或体系域的发育具有明显的制约作用,往往构成盆内重要的油气成藏区带。中国西部大型叠合盆地内古隆起的形成演化和隆、坳格局的变迁可导致复杂的层序结构和不整合分布样式,对地层或构造地层圈闭的形成分布具有重要的控制作用。

Comprehensive analysis by combination of basin tectonism during basin formation and evolution with the basin filling and reforming is the key to reveal the configuration of depositional systems and the source, reservoir and seal in the inland tectonically active basins. The development and distribution of different order tectonic unconformities and sequences determined the basic characteristics of the chronstratigraphic framework. The polyphasic and episodic tectonism of these basins usually had a significant influence on the regional deposition-erosion cycles and the depositional patterns. It is the key for reconstruction of the basin filling patterns to document the control of the activity of syndepositional structures and the paleostructural framework on the sediment disposal and the variation in tectonic paleogeomorphology. The structural slope break zones usually constrained the development of distinguish facies zones or depositional systems tracts, such as lowstand deltaic or lacustrine fan systems in Mesozoic and Cenozoic rift lacuastrine basins and reef and bank facies zones in the Paleozoic carbonate platform in Tarim Basin, and comprise economically important plays in the basins. The formation and alteration of uplifts and depressions resulted in the complex stratigraphic architecture and unconformity configuration, which significantly constrained the formation and distribution of stratigraphic or structural-stratigraphi c traps in the large superimposed basins in the western China.