Non-karstic Caves of the Cserhát Mountains
The 3000 km2 Cserhát Mountainsform the hill countryof the North Hungarian Mountains between the Börzsöny and MátraMountains. The major part of the landscape consists of low hills formed of sandstone and clay. In the south-western area of the region, tectonic upheaval has caused Triassic limestone blocks to rise from the younger sediments.In the middle and eastern areas of the mountains andesite rift volcanoes appear.
The caves of the region are very diverse as a consequence of the varied geomorphology, the different rock formations and the complex development of the landscape (repeated uplifting, sinking and volcanic activity).About120 karst caves are known in the Triassic limestone blocks, whichcoverless than 1% of the area (20 km2).
The 24 non-karstic caves have developed mainly insedimentary formations and subordinately in volcanic rocks. Six caves occurin calcareous, in quartziferous or in marly sandstone. In marly clay andin compact clay (called "slir" locally) 3 caves have been listed.
Five caves have developed in andesite. Tree moldcaves occur in rhyodacite tuff beyond the Hungarian border in Slovakia and in andesit-conglomerate- sandstone formation near Nógrádszakál village. Seven other caves are known in the surrounding of Nógrádszakál village also in andesit-conglomerate - sandstone formation. Ten artificial caves in andesite tuff and in loess have also been listed, because they are considered as caves by the local population.
Three of the four cave in andesite are syngenetic.They have been formed by a volcanic steam explosion ( Függ õ-kõi Cave, "Dupla-üreg" and the now destroyed Sámsonházi Bubble Cave), which are witnesses to the intensity of the Miocenevolcanic activity. The fourth non-karstic cave, the Sárkányfürdõ Cave has been formed by the lateral erosion of Cserkúti Creek.
One cave is known in andesite agglomerate. The 21m long Erd õkürti Andesite Cave opensin a quarry. It appears to be a syngeneticcave. On the swampy moorlandfalling hot volcanic gravel heated upthe swamp water, pressure of the steamwhich was generated as a result of this caused a hollow to form in the andesiticgravel.
In the marly clay, in sandstone, and in compactclay, the caves are usually formed as a result of rock fragmentation. TheFels õpetényi Cave and the PappenheimCave are the results of this break down. The Bercel-hegyi Cave isthe result of erosion, while the Sz õlõ-hegyi Caves were formed by collapse.The Betyár Cave in Szentkút has undergone a complex development. Erosion, dissolution and rock fragmentation have all played part in the formation of this cave.
In several non-karstic caves in the CserhátMountains (Betyár Cave, Függõ-kõiCave and Pappenheim Cave) paleontological excavations were carried out.As a result of these excavations 35 species of molluscs and 100species of vertebrates have been found from the Würm to the Holoceneperiods.
The following caves are longer than 10 m in theCserát Mountains:
|
1. |
Betyár Cave |
Carbonateous sandstone |
Mátraverebély |
61,7 |
/±6 m |
|
2. |
Remete Caves |
Sandy, clayey marl |
Mátraverebély |
32,7 |
/+2 m |
|
3. |
Felsõpetényi Cave |
Quartziferous sandstone |
Felsõpetény |
30 |
/+28 m |
|
4. |
"Kõlyuk" |
Sandstone |
Kishartyán |
22 |
/+2 m |
|
5. |
Erdõkürti Andesitecave |
Andesite agglomerate |
Erdõkürt |
21 |
/-2 m |
|
6. |
Pappenheim Cave |
Sandstone |
Buják |
11,5 |
/+2,5 m |
The total length of the non-karstic caves is 207m and the lengthof the artificial caves is 33 m.
