广东碳酸盐溶洞发育的控制因子

THE CONTROLLING FACTORS OF KARST CAVES DEVELOPMENT IN GUANGDONG PROVINCE

广东省碳酸盐溶洞主要分布在粤北的韶关、清远两市。基岩岩性、地貌位置、水文条件、地质构造和气候条件是该地区溶洞发育的主要控制因子。广泛分布于华南岩溶山区、多级台地、山间盆地的晚古生代厚层碳酸盐岩是溶洞发育的物质基础 ;充沛的降水和活动频繁的地下水是溶洞发育的动力因子 ;褶皱核部。

Karst caves in Guangdong Province, South China, are distributed mainly in Shaoguan and Qingyuan. Karstification intensely happened in pure and thick carbonate rock strata. The density and the dimension of the caves are evidently connected with the geomorphic feature and water resources. Big caves increase in karst mountains, platforms, river valley of plains between-mountain basins and the areas abounding in drainage. The great and long caves are distributed usually over riverside or upper and middle reaches, while the small ones along the lower reaches and far away from the riverbank. Geological structures are important factors in cave development. Many caves lay in cores and limbs of the folds, and often parallel or coincide with the fold axis. The karstification processes occur along the belts of fracture and fault too. Because impacted by the interrupted vertical movement and controlled by the releasing base level of the karst, they often form horizontal caves having many layers in river bank. Some caves have storey textures, which indicate the period and phase of the karstification. The investigation reveals that climate conditions such as precipitation, evapotranspiration and air temperature are the major factors of caves growing. Under normal conditions, when the climate is damp and hot, with abundant rainfall and high temperature, karstification is intensely developed.