喀斯特地区洞穴壶穴形态的形成与发育

摘要

Riverbed potholes in karst caves are significant indicators of micro-scale geomorphic evolution as well as underground drainage development.They has been known as convincing evidences of interaction between subsurface flow and cavern riverbed conditions.In this study,in-depth investigation were mobilized to explore the formation and feature of cavern pothole.A number of 108 caves were selected for survey in a section of Loushanguan dolomite underground riverbed of Suiyang Shuanghe cave system,Guizhou province.Results confirmed there are two forms of underground riverbed potholes,plunge pothole and eddy pothole.Their sizes,shapes,and distribution were controlled by underground hydraulic effects and evolution of subterranean drainage.Riverbed potholes appeared to be a relative regularity in formation as compared with those of potholes growing on ground surface riverbed.It was interpreted a long-term stabile cavern environment,a ultimate formation of cavern pothole as well as its ensuing evolution,all of those have derived from a combined function of underground hydrodynamic conditions,cavern drainage system,lithology,and alluvial deposits.This research will provide scientific proofs and insights for the formation and development of cavern pothole landscape,and it will enrich and refine researches on the characteristics and origins of caves at different geomorphological locations,with varied lithologic properties.Also the research achievements will form solid scientific basis for further investigation on cavern microrelief evolution and do contribute to development of cave hydrodynamics.%喀斯特洞穴河床壶穴是记录洞穴微地貌演化、洞道走向、水流与地下河床边界条件相互作用的关键性证据之一.通过对贵州绥阳双河洞穴系统,属娄山关组白云岩地下河段108处洞穴壶穴的形态及分布特征进行实地仔细观察和分析发现:该区地下河河床壶穴分为两种形式即跌水壶穴(plunge holes)和旋转流壶穴(eddy holes).它的规模、形态及分布特征规律性较地表河床壶穴强,主要受水动力、洞道走向控制.由于洞内气候环境长期稳定,洞穴河床壶穴的形成与演化主要是水动力条件、洞道走向、岩性、洪冲积物综合作用的结果.本研究结果将丰富与完善壶穴不同地貌部位、不同岩性特征及成因,为洞穴河床壶穴形态的形成与发育提供科学论证,为洞穴微地貌演化过程及洞穴水动力研究发展提供科学依据.