Rock structure is multiple nested pore structure.There is similitude or approximate similitude or statistical similitude between every hierarchy,so pore structure is typical fractal structure.

• 岩石结构是多层次嵌套的多孔结构,每一层次之间是自相似或近似相似或统计意义上的相似,所以说岩石结构是典型的分形结构。