黄山第四纪泥砾沉积物分形结构特征与成因机制分析

Analysis on the Fractal Structure Features and Formation Mechanism of the Quaternary Boulder Clay in the Mt. Huangshang

黄山第四纪泥砾沉积物粒度组成的分维值介于２７０８～２７３５之间，非常接近古泥石流堆积物粒度组成的典型分维值２７５．结合沉积特征，表明该沉积物属第四纪间冰缘环境下的稀性泥石流沉积。

The Quaternary boulder clay in the Mt. Huangshan is distributed mainly on the foot of mountains,ranging from 400 to 800 m a.s.l. There are many hypotheses to explain the formation of this sediment. In this paper, the author analyses the fractal structure features of the Quaternary boulder clay in the Mt. Huangshan based on the fractal theory. It is found that the fractal dimension changes from 2 708 to 2 753, very close to the fractal dimension of the sediments of ancient debris-flow (2 75). It is known that the fractal dimension of the non-cohesive debris-flwo is over 2 6. So, the Quaternary sediments in the Mt. Huangshan is thought to be ancient non-cohesive debris-flow. According to the features of the sediment, the climate was warm and wet during its deposition. The environment of the Mt. Huangshan during the Quaternary glacial epoch was periglacial one of the monsoon-type. This sediment resulted from ancient non-cohesive debris-flow in the monsoon-type interperiglacial environment. Its formation had something to do with the monsoon-type periglacial environmrnt.