The development of karst landscapes in Vietnam

Abstract

The main factors controlling the development of tropical karst landscapes in Vietnam are structural and Iithological properties of carbonate rocks, tectonic movements, and the position of ground-water levels. Corrosional undercutting and the subsequent gravity collapse of rocks is the chief mechanism involved in the retreat of karst walls and the formation of flat-floored karst depressions. This mechanism comes into action when the negative forms produced by vertical corrosion reach the ground-water level and it is effected by agressive swamp waters or, at sea level, by subsaline marine waters. The role of tropical climate is important in providing huge amounts of solvent by means of heavy rainfalls and by elimination of frost splitting, which in temperate climatic zones is the most effective factor acting upon the exposed limestone walls.