沉积物理模拟实验在确定重力流临界坡度中的应用

Determination of the gravity flow critical gradient using sedimentary simulation experiment

主要采用沉积物理模拟实验的方法,分别对不同成因重力流的启动临界坡度进行了探讨,并对重力流的滑动临界坡度进行了分析。不同成因重力流的启动临界坡度存在较大差异,斜坡梯度大致为6m/km的斜坡带足以发生砂质碎屑流,洪水型浊流所需要的坡度最小;斜坡高差是影响沉积物再搬运重力流发育的重要条件,因此再搬运重力流所需要的坡度最大;而重力流在坡度大于0.1°时即可以滑动。重力流的启动临界坡度是形成重力流的关键。并且结合实例,分析了松辽盆地南部重力流的沉积特征。

The gravity flow deposit system in deep-water is still the focus of the study. But there are more factors that affect the development of gravity flows. A systematic study and identification of the critical slope of gravity flow deposition has not been made. It is important to explore the start-up and sliding of critical slopes of different genetic gravity flows by sedimentary physical simulation. The research shows that there is a great differences between critical start-up slopes of different genetic gravity flows. When the slope grad is about 6m/kin, the debris flow will produce. The flooded turbid flow production needs the smallest grade. The slope grade is the most important factor that the regenerate gravity flow produces. The regenerate gravity flow production needs the biggest slope grade. A gravity flow will slide when the slope exceeds 0. 1°. The critical start-up slope is the key factor that causes gravity flows. The paper analyzes the features of the gravity flow sediments in the south of Songliao Basin combined with the sedimentary simulation experiment.