ABSTRACT
The term “karst valley” was introduced by Cvijić (1893) who provided a fourfold classification into pocket, blind, semi-blind, and dry valleys. Blind and dry valleys were subdivided into primary valleys, formed by allogenic rivers flowing from impermeable rock, and secondary valleys, formed in the bed of a normal karst river. Roglic (1964) argued that the term “karst valley” should be discontinued because strictly valleys are the result of water flowing overly the surface and are formed by fluvial, as opposed to karstic processes. Sweeting (1972, p.103) suggested that many would find this an overly pedantic view but that karst valleys should be recognized as “the most important of the landforms occurring in the karst which are not produced by true karst processes”. Her fourfold classification into through (allogenic), blind and half-blind, pocket, and dry valleys is followed in this review. Valleys are a feature of most karst regions, the exceptions ‘being areas of polygonal karst where the whole surface is pitted by dolines, although even here there may be vestiges of former valley networks. However, there are also some karst regions where the surface is dissected by a dense network of valley systems forming a fluviokarst (see separate entry).
