锅穴一定是第四纪冰川的标志吗?  

ARE ALL POTHOLES MARKERS OF QUATERNARY GLACIATIONS?

作　　者：周尚哲[1] 

机构地区：[1]华南师范大学地理科学学院,广州510631

出　　处：《第四纪研究》2006年第1期117-125,共9页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:40371013)资助

摘　　要：锅穴地貌现象在西方地学界已有长足的研究,在中国地貌学界也并不陌生。锅穴通常形成于山区溪流河床,也形成于风化风蚀、石灰岩溶蚀、湖滨海岸浪蚀等作用。北美、北欧末次冰期大冰盖覆盖过的地方有冰水形成的锅穴。因此,锅穴是一种多成因的地貌现象。见到锅穴而不加多方辨别论证,一概说成是冰川形成,显然是十分危险的。风化和溶蚀形成锅穴属于物理化学作用,而流水和浪蚀形成锅穴属于水动力作用。关于水动力如何形成锅穴,西方地学界早就形成了公认的解释。冰水锅穴经过反复研究也确认,其形成机理与山区河流无异,均属湍急流水在河床局部形成环流驱动沙砾长期磨蚀的结果。既非西方人19世纪提出的“Mou lin Hypothesis”能够成功解释,更非眼下国内少数人倡导的“滴水穿石”能够说明。河谷跌水比想象的冰川终端冰崖缺水更加有利。Numerous publications have shown that potholes with various origins have been well studied in the international geomorphological field. Potholes formed by glacial melting water certainly have been discovered from North America and Scandinavia, where they were covered by ice sheets in the LGM. Potholes however have been also confirmed to be formed by abrading action of pebbles and cobbles that are carried by eddy in turbulent streams, by salt weathering and wind erosion in arid environment, by corrosion in karst areas, and by ocean and lake erosions as well. It is thus dangerous to say, without distinguishing, that all potholes were of glacial origination. The salt weathering and corrosion are results of physical and chemical processes while current and wave erosions are caused by hydraulic power processes. The mechanics of formation of glaco-fluvial pothole was thought to be of no difference from those formed in mountaineous river valleys. They could be explained neither by Moulin Hypothesis nor by Glacial Terminal Fall Hypothesis. Any geomorphological phenomenon should be associated with its geographical environment.

关 键 词：锅穴 冰臼 第四纪冰川 

分 类 号：P534.63[天文地球—第四纪地质学]