贵州施秉白云岩溶蚀特性及孔隙特征实验研究

以贵州施秉白云岩为研究对象,从宏观和微观角度分析白云岩的溶蚀特性及孔隙特征,结果显示:(1)在众多影响施秉喀斯特发育的因素中,矿物成分是最基本的内因,水是最关键的外因,孔隙结构起辅助作用。(2)极细晶白云岩的单位表面积溶蚀量一般大于细晶白云岩的,在晶粒相同的情况下,白云岩的溶蚀量与Ca O和Mg O的含量分别成正比,且Mg O的含量影响较Ca O大。(3)施秉白云岩溶蚀速率不仅受岩石矿物颗粒粒径大小的控制,还受岩石内部孔隙结构特征的影响,颗粒粒径越大,孔隙度越高,连通性越好,越有利于水溶液进入,溶蚀量也就越大。(4)施秉白云岩的溶蚀特性是多种因素综合作用的结果,必须把各个因素分离开来,从宏观和微观角度逐个作详细的分析研究,然后综合起来,才能对喀斯特发育规律有更深入的了解。

The Experimental Study of Dolomite Dissolution and Pore Characteristics in Shibing, Guizhou

With dolomite in Shibing of Guizhou Province as the study object, the authors analyzed its dissolution characteristics and pore characteristics macroscopically and microscopically. Some conclusions have been reached: (1) In many factors that influence the development of Shibing karst, the most fundamental factor is mineral composition, the most critical factor is water, and pore characteristics play a supporting role; (2) The dissolution amount on per unit surface area of superfine grain Shibing dolomite is generally greater than the amount of fine-grained dolomite rock sample. Under the same circumstances of grain dissolution principle, the dissolution amount of dolomite is in positive proportion with CaO and MgO content and the influence of MgO content is larger than that of CaO content. (3) The dissolution rate of Shibing dolomite is not only controlled by particle size of the mineral particles, but also by the internal pore structure characteristics of the rock. The larger the particle size, the higher the porosity, the better the connectivity, the more the beneficial solution seeps into pore, and the greater the amount of dissolution; (4) Dissolution of dolomite is the result of many factors, and all factors must be separated one by one to make a detailed analysis from the macroscopic and microscopic view. On such a basis, more information about the regularity of the karst development can be obtained through a comprehensive study.