现代地质Issue(2)：438-442,5.
泥石流堆积物的粒度特征及分形结构：以金沙江上游干热河谷区瓦卡泥石流沟为例
Grain Size Characteristics and Fractal Structure of the Debris-flow Deposits:An Example from the Waka Debris-flow Gully in the Dry-hot Valley of the Upper Jinsha River
摘要
Abstract
Taking the Waka debris-flow gully in the dry-hot river valley area of the upper Jinsha River as an ex-ample,the concept of sedimentary facies was introduced and the debris-flow sedimentary types were divided ac-cording to the characteristics of the sedimentary facies.The debris-flow sedimentary facies of Waka profile were divided into three types,Facies A (coarse-gravel layer),Facies A1 (fine-gravel layer)and Facies B (surface mud layer),i.e..Three or four samples were collected from each unit and 6 1 samples were collected in all and their grain sizes were analyzed.The characteristics of grain-size distribution and fractal structure of these sam-ples were analyzed based on grain-size data.The results show the following aspects:(1 )The curves of the grain-size distribution of the three sedimentary facies are all of bimodal type,reflecting bad sorting of sedimenta-ry materials for debris-flow deposits.(2)Facies A and Facies A1 are of coarse-fine mixed gravel layers,and the grain-size distribution is not uniform.However,Facies B is of clay layers which include few or no gravel,and the grain-size distribution is more homogeneous.(3)The fractal features of Facies A and Facies A1 are more ap-parent than that of Facies B,and the grain-size fractal dimensions of Facies A and Facies A1 are 2.692,1 and 2.697,1 with relative coefficient of 0.868,2 and 0.832,2,while the grain-size fractal dimension of Facies B is 2.9007 with relative coefficient of 0.43.The differences of grain-size distribution and fractal feature among Facies A,Facies A1 and Facies B reveal that these three debris-flow sedimentary facies formed in different sedi-mental environments.关键词
泥石流/沉积亚相/粒度分布/分形结构Key words
debris flow/sedimentary sub-facies/grain size distribution/fractal structure分类
天文与地球科学引用本文复制引用
陈剑,陈松,慎乃齐,刘丽娜,崔之久..泥石流堆积物的粒度特征及分形结构：以金沙江上游干热河谷区瓦卡泥石流沟为例[J].现代地质,2014,(2):438-442,5.基金项目
国家自然科学基金项目（40901005）。 （）
