贵州绥阳响水洞洞穴壶穴形态的形成与发育

Formation and Development of Karst Cave Pothole Forms:An Example from Xiangshui Cave in Suiyang County,Guizhou Province

为探究响水洞壶穴的形成和演化的机理,对白云岩地区洞穴壶穴形态特征(长轴长、短轴长、深度、长轴所对应的走向及洞道走向等)进行了详细测量,并运用统计学分析方法从定量的角度描述了洞穴壶穴的形成和发育过程。结果表明,壶穴的形成和发育过程不仅与流速有关,还与洞道走向、洞道宽窄、弯曲程度和流水特征有关;壶穴的空间分布与洞道走向有着密切的关系,因其形态受节理构造、流水形式等作用控制,其长轴走向具有一定的选择性;对壶穴长、短轴作对数变换后之间具有很好的线性关系,其回归曲线是幂<1的函数曲线;而对长轴和短轴与深度作对数变换后之间相关性较差,回归曲线分别是幂<1和幂>1的曲线,故而在壶穴发育的过程中,其形态和流水作用的形式也是随机的;喀斯特洞穴壶穴是地下河下切的侵蚀形式之一,在下切强烈的洞段,其形成时间相对较短,且发育不充分,难以长久保存,因此现代地下河的壶穴即是现代壶穴。对喀斯特地区地下河道中壶穴的分析和研究,丰富了岩石坑穴的研究,对岩石地貌学的研究具有一定的意义。

In order to study the mechanism of the formation and evolution of Xiangshui Cave potholes in Guizhou Province, this article presents the detailed measurements of their morphological characteristics, the length of the long and short axis, depth and the orientation of the corresponding long axis to the orientation of the caves and then describes quantatively the formation and the development of the caves by statistical analysis. The results show that the formation and development of the cave potholes is not only related to flow velocity, but also to the cave orientation, width and bending as well as the flowing water features. Also, the spatial distribution of the potholes is closely related to the cave orientation for the cave forms are subject to the joint structures and flow forms and the axisis show certain selection. The development of the caves has a good linear relation with the long and short axis, whose regression curve is a function curve of power 〈 1 while, the correlation between the long axis, short axis and depth is poor, whose regression curve is the curve equation of power〈1 and power〉1. Therefore, the cave shapes and flow forms can be random during the cave development. The karst cave is one of the erosion forms of underground river pothole by down cutting, and so in the lower part, the formation time is relatively short, and development is not very good enough for long-term preservation. This indicates that the modern underground river cave potholes should be the modern ones. The analysis of the karst underground river pothole may enrich the study of rock pitholes and rock geomorphology researches.