Veress Márton: A Bakony természettudományi kutatásának eredményei 23. - Covered karst evolution... (Zirc, 2000)

KARSTIFICATION

Valley evolution through cavity exposure gradually stops. This is cause by the decreasing rate of valley incision with the removal of cover sediments. Thus, cavity formation and, as a result, valley evolution slows down. Cavity exposure is sometimes only typical of some sections of superimposed-regressional valleys instead of their whole length. Such sections are indicated by groups of cave remnants. The branching of these caves in various directions points to the one-time groups of cavities. The position of the group of cave remnants related to the channel is an evidence of the influence of stream erosion, whether the latter affected the margin or the interior of the former group of cavities (Fig. 59). This subtype of karstification is characteristic of the valleys incising in the area of the Sűrű Mountain Group. The valley evolution subtypes with collapse dolines and through cavity exposure are usually not distinct spatially. Thus, for instance, in the area of the Sűrű Hill, Dudar, landforms of cavity exposure and collapse doline origin appear next to each other and it shows that the subtypes alternated. (Here human intervention has changed the morphology of collapse dolines in many sites.) All these allow that on blocks originally in low positions karstification resulting in collapse dolines was replaced - as a consequence of uplift - karstification with valley evolution through cavity exposure if patches of cover sediments were preserved in the catchments of valleys. Valley evolution exclusively through cavity exposure is only possible if the karst water table was in low position related to the carbonate basement even in the initial stage of development.