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

KARSTIFICATION

Fig. 16. Development and karstification of depressions Legend: a. untilted carbonate basement, no denudation in broader environment, no depression, no karstification; b. untilted carbonate basement, denudation in broader environment, depression development, karstification on its edge on exhuming side; c. tilted carbonate basement, no denudation in broader environment, no depression, karstification on elevated cones because of the reworking of local sediment; d. tilted carbonate basement, exhumation in the broader environment, depression formation, karstification on its edge on exhuming side; 1. carbonate rock; 2. cover sediment; 3. original surface of cover sediment; 4. sheet wash undifferentiated; 5. sheet wash partly in intervals between cones; 6. karstification along hidden rock boundary; 7. material transport in depth The depressions are referred to pseudodepressions (Picts. 16, 17; Fig. 20) and true depressions (Picts. 19,20,22; Figs. 18,55). The basin of interior drainage is a pseudodepression if there are no landforms with interior drainage on the carbonate terrain under cover sediments or if the area of this landform is smaller than that of the pseudodepression. (The complete surface erosion of coversediment patches is hindered by the elevations of gradually exhuming carbonate rock around the pseudodepression.) A true depression is a closed basin with a landform of interior drainage (further: paleokarst depression) under the cover sediments. A preconditon to the development of both pseudodepressions and true depressions is that cover sediments should be removed from their environment by sheet wash or stream erosion (Figs. 17, 18). After the carbonate rock outcropped, further removal from the surface is prevented by the edge of the basin (for both types) or, in case of pseudodepressions, the joint base of cones or the frost-shattered debris between cones. During material transport to depth, pseudodepressions reach various stages of development. Half-enclosed (Fig. 19) and then completely enclosed (Picts. 16,17; Fig. 20) depressions are produced. Within enclosed depressions a growing proportion of karst features (dolines-with-ponor) are fossilized. A mature depression results (Fig. 21) with more and more covered karst depressions (Fig. 22). Because of material transport to depth at more and more sites of karstification, the immediate surroundings of the previously fossilized