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

KARSTIFICATION

Such a type of karstification is common on the Tés Plateau (Figs. 53, 54, 55). Here several stages of karstification must have occurred with interruptions when non-karstic geomorphic evolution prevailed. (The non-karstic stages were modified by the products of the previous phase of karstification, while non-karstic evolution, denudation or accumulation, also had an effect on the following stage of karstification.) The probable stages of geomorphic evolution are the following (Fig. 56). - Ponor development through bathycapture (true capture) on the floors of superimposed valleys along rock boundaries (allogenic karstification). The retreat of captures produced doline rows. - The subsequent uplift of the plateau resulted in the complete removal of teh Csatka Gravel Formation, probably through pedimentation. The superimposed valleys were partially truncated. - In the area of interfluvial ridges (or in terrains without valleys) authigenic karstification was active (probably with doline formation). - As a consequence of loess formation and the subsequent sheet wash (removing eg. matter from the neighbouring valley slopes), swallow dolines fill in and become covered. Dolines formed during authigenic karstification fill in only partially since those formed on interfluvial ridges or in terrains without valleys hardly any sediment could accumulate. - In the fossilised features postgenetic (in fossil ponors) or syngenetic (in fossilised dolines) karstification begins. The streamsink caves or alluvial streamsink caves and avens in the mountains developed during allogenic karstification. It is indicated by the large dimensions of caves, the erosional sections in caves and the partial or entire absence of collapse material in the upper part of aven-like features. Indirect evidence is supplied by the gravels or red clay in some fossilised karst features. (The latter points to the existence of these landforms even between the pedimentation and loess deposition stages.). The relict karstification in the recent past and in the present generates cavernation, which is, in fact, chimney formation. Chimney formation is largely affected by the cavities and passages developed during allogenic karstification. It means that chimneys originate under surface depressions but develop from below, fromm the previously formed passages towards the surface. Syngenetic karstification probably occurs in fossil dolines where the chimneys, developing from cavities to the influence of infiltration, rise close to the surface of the carbonate rock if the depression nature is preserved (water from the environs collects here) and if the sediment fill is permeable (Fig. 12, 56).