长白山天池火山泥石流堆积物粒度分布及其结构维数

对堆积物的粒度进行分析,可以为研究火山泥石流的形成机制、数值模拟等提供参考数据。为了对长白山天池火山泥石流堆积物进行研究,在二道白河镇附近对长白山天池的古火山泥石流进行了勘察,取了2组共12个火山泥石流堆积物样品。对第1组进行了粒度参数法分析,得到了火山泥石流堆积物的平均粒径、分选系数、偏度和峰度,认为长白山天池火山泥石流堆积物的分选较差,沉积以粗组分为主。基于从第2组6个样品的分析可以推断,长白山天池火山泥石流主要为稀性泥石流,泥石流堆积物粒度分布较不均匀,分选较差,粒度分布接近正态分布。研究表明,粒度参数分析和结构维数计算相结合可以很好地了解火山泥石流堆积物的分选性、粒度分布情况、泥石流的类型等。

Grain-size distribution and structural dimension of Tianchi Volcano lahar deposits in Changbai Mountain region

Grain size analysis of lahar deposits can provide reference data to lahar formation mechanism,numerical simulation,etc.To study the lahar deposits of Changbai mountain,we explored the ancient lahar deposits in Erdaobaihe Town near Changbai mountain,obtained 12 lahar deposits samples in 2 groups,and analyzed the first group’s 6 samples with grain size parameters method,acquired the mean grain size,sorting coefficient,skewness and kurtosis of lahar deposits.From the result of analysis,it can be known that the lahar deposits in Changbai mountain region is bad sorting,and the components mainly consist of deposit coarse grain.Deduced from the analysis of 6 samples of the second group,it can be seen this lahar is thin viscous debris and its grain sizes are non-uniform,bad sorting and close to normal distribution.Results show that comprehensive utilization of grain-size distribution and structural dimension analysis could understand sorting,grain-size distribution and type of lahar deposits very well.