松辽盆地西部坡折带的成因演化及其对地层分布模式的控制作用

The Origin and Evolution of Slope Break Belt and Its Effect on Stratigraphy Distribution in Large Down-warped Lake Basin

大型坳陷湖盆中存在与海相盆地中陆坡相似的坡折带。松辽盆地西部发育套堡—双岗高位坡折带和红岗—海坨子低位坡折带两级坡折带,本次研究系统分析了坡折带的成因演化及对其地层分布的控制作用。早期两级坡折带都受到基底断裂的影响,后期发育过程中套堡—双岗高位坡折带物源的方向和侵蚀力是其主控因素,红岗—海坨子低位坡折带后期主要受沉积物的供应和差异压实作用的影响。套堡—双岗高位坡折带和沟槽的共同作用控制了沉积体系的展布,红岗—海坨子低位坡折带控制了低位域发育的范围。

The slope belt developped in large-type down-warped lake basin is similar to the slope in the marine basin. The Songliao Basin can be identified as two slope belts, and this paper analyzes the origin and evolution of slope belt and its effect on sediment system and stratigraphy distribution. The two slope belts are all influenced by the fault during the early periods. With the development of slope belt Taobao-Shuangang high water level slope is controlled by the direction of provenance and erosion, but the sediment supply and the differential compaction are main controlling factors in the development of Honggang-Haituozi low water level slope. The evolvement of the Sediment system is controlled by the Taobao-Shuangang high water level slope and groove, but the Honggang-Haituozi low water level slope controls the range of lower system tract.