Róka-hegy Cave

Róka-hegy Cave is one of the highly protected caves of Hungary. It is located in the Pilis Mountains within the Danube–Ipoly National Park. It became famous primarily because of its minerals. The cave entrance is currently buried.

Description

The cave opened on a plot between houses number 20 and 24 on Kormorán Street at the top of Róka-hegy, the southeasternmost peak of the Pilis Mountains, but its entrance is currently made inaccessible, filled in and therefore impassable. The cave begins after a well‑ringed, 14‑metre‑deep artificial shaft.

Its upper part formed in Eocene limestone, the lower part in Triassic limestone. The meeting of the two rocks is at the narrow, artificially widened section called Cápaszáj. The cavity formed due to the intrusion of mixed, lukewarm water. The water followed a roughly 10‑centimetre‑thick calcium carbonate layer and an almost perpendicular crack. This calcium carbonate layer is visible throughout the cave. The cavity formation occurred in the older Pleistocene stage or at the end of the Pliocene. The passage in the Triassic limestone is much larger than the passage in the Eocene limestone. Its deepest point is filled with rock debris.

The precipitation seeping in from the surface caused the many speleothems, which are relatively undeveloped and small. In the passages there are pea‑stones, which in the upper part of the cave formed by condensation dissolution, and in the lower part formed and grew due to evaporation, later small dripstones grew on them. The cave contains spherical chambers, spherical columns and also pea‑stones that originated on dripstones. Its special value is the crown‑shaped pea‑stone first described from here, which occurs in large numbers.

The mine system also described barite appearing in tabular crystals, strongly sparkling crystalline gypsum sand, branching, twisted and needle-like gypsum formations, limonite nodules formed from marcasite, mountain milk, branching, yellowish‑white‑light‑brown cauliflower‑like pea stones, crystal aggregates composed of 1–5 centimetre long, radiating aragonite needles, radiating calcite, lublinite, aragonite, goethite and straw‑dropstone.

From the passages Bartha Zsuzsanna identified 13 algae species. Of these, three were already reported from the Mátyás‑hegy cave by Palik Piroska, two from the Pál‑völgy cave by Suba Éva, four occurred in the Béke cave, and two also occurred in the Baradla cave according to the research of Claus György.

Loksa Imre found four springtail species, including Folsomia candida, which has been found in Hungary only from caves, a few fly species such as the blue hoverfly, and a beetle species in the cave, as well as an exactly undetermined Trechus species.

The cave is essentially a steeply sloping mine system and a spherical chamber system, whose final section is a deep vertical passage about 25 metres deep.

Among the three highly protected caves of Üröm, one is this cave, the other two are the Amphitheatre cave and the Üröm water‑draining cave.

The cave occurs in literature under the names Crystal Cave (Kordos 1984), Fox Cave (Csulák 1982), Róka-hegy Cave (Kordos 1977), Rókahegyi stalactite cave (Németh 1975), Rókahegyi-cave (Barátosi 1959), Rókahegyi cave (Szilvássy 1960), Rókahegyi sulphuric cave (Bertalan 1976), Rókahegyi sulphuric cave (Szilvássy 1960), Rókahegyi-crystal cave (Leél-Őssy 1958), Rókahegyi crystal cave (Bertalan 1976) and Rókahegyi new cave (Bertalan 1976). In 1977 the cave was first called Róka-hegyi-barlang in the literature. The Róka-hegyi-barlang is identical with the cave mentioned as the ancient spring cave of Romaifürdő in the October 1959 issue of the Karst and Cave Research Bulletin (this identification appeared in the December 1959 issue of the Karst and Cave Research Bulletin and comes from the editor, Balázs Dénes). The nearby Róka-hegyi Crystal Cave also has name variants Crystal Cave and Rókahegyi new cave.

Research History

In the study published in 1958 and written by Sándor Leél-Őssy, this cave may be described under the name Rókahegyi-crystal cave. According to the description, the entrance of the cave is located in a large stone quarry at the K end of Róka-hegy, at an altitude of about 220 m above sea level. At the cave entrance a large, characteristic sulphur spring funnel can be observed, which is clearly visible from a distance. It was opened by stone mining and the originally closed cavern was discovered. Part of the cave was mined, which is now about 30 m long and about 10 m deep. The characteristic sulphur-formed cave (old sulphur spring funnel) was formed in Dachstein limestone. It is now very deteriorated, dry and becoming blocked. György Kertai wrote about the many pea‑sized aragonite crystals in the cave, which have precipitated from the sulphur waters. The limestone in the cave crumbles a lot because of the sulphur effect. A map sketch was attached to the study, showing the Kevély mountain group. The map sketch shows the geographical location of the Rókahegyi-crystal cave. In the drawing and the text the cave is marked with the number 1.