Fazekas-hegyi Cave

Fazekas-hegyi Cave is one of the caves located on Fazekas Hill in the Danube–Ipoly National Park, in District II of Budapest.

Description

The cave entrance is in a former, now non‑operational stone mine dug into the southern side of Fazekas Hill in District II of Budapest. It is easily reachable by car from the stone quarry, because Torda Street ends almost at the quarry. The Fazekas-hegyi Cave, located in the Buda Landscape Protection Area, has an arched, natural, slope‑axis‑oriented entrance 1.2 m wide and 1.25 m high, lying at the foot of a rock wall in the western part of the stone mine. Above the Fazekas-hegyi Cave, in the rock wall, is the entrance to the Fazekas-hegyi Upper Cave. Both caves lie along the same well‑defined tectonic fissure and could be joined together.

Formed in Upper Triassic Dachstein limestone, the Fazekas-hegyi Cave is 10.5 m long, 0 m high, 4.4 m deep, with a vertical extent of 4.4 m and a horizontal extent of 7.1 m. The cave’s location and formation were determined by a significant tectonic fissure, followed by the direction of the cavity system’s development. The cavity was created by tectonic displacement, dissolution below the karst water level, corrosion and collapse. The sloping, tunnel‑like section beyond the entrance has a ceiling of flintstone, but at the bottom of the slope and in the interior the ceiling and the southern side wall consist of large collapse blocks and clayey sediment. The floor of the interior of the cave is also filled with red clay, while its front part is characterized by humus‑rich, plant‑debris sediment. The entrance area of the cave is greenish due to an algal‑moss coating. Many pieces of trash are found in this area, but since the quarry is very littered, it is also fortunate that the cave has not been filled with garbage.

The fissure-shaped cave floor slopes and the characteristic cross-section type is the fissure cross-section. Dome, breccia zone and ancient artifacts can be observed in the cavity system. The formations are mainly characteristic of the middle part of the fissure-like cave, they are not spectacular and are currently not developing. The mineral filling is massive, consisting of pea‑sized clastic deposits, dripstone clastic deposits and calcium carbonate layers. Rounded, solution‑eroded forms are not characteristic of the free‑standing wall surfaces. The clay filling in the interior of the cave could be easily removed (traces of such work are also visible), but the work would be hazardous because of the risk of collapse; therefore this activity could only be carried out with great caution and with ceiling support. The cave, which can be visited without a permit, is accessible by an easy walk and is easily traversable.

In the literature the cave occurs under the names Fazekas‑cave (Bertalan 1976), Fazekashegyi cave (Bertalan 1976), Fazekas‑hegyi‑fissure cave (Kordos 1984), Fazekashegyi water sink (Bertalan 1976) and Fazekas‑hegyi‑water sink (Kordos 1984). In 2004 the cave was called Fazekas‑hegyi‑cave for the first time in the literature.

Research history

In the 1963 Karst and Cave Research Bulletin, in the report of the BEAC Cave Research Group on its 1962 work, it is written that in 1962 the group members found sulphuric traces in the tectonic fissure of the Dachstein limestone on Fazekas‑hill (Hűvösvölgy), in the quarry facing Torda Street. According to geological maps, freshwater limestone is present in the area. From the presence of the sheet‑like calcite in the fissure and the freshwater limestone discoverable nearby, the group members inferred the existence of a sulphuric‑origin cave. From the fissure they were able to explore about 10 m downwards at an angle from the fissure entrance. Sulphuric traces appeared at the end of the fissure, where they proceeded a few metres further between collapse blocks. The work on Fazekas‑hill was halted because it was life‑threatening. The work can only be continued if appropriate equipment is available.

The 1964 Karst and Cave Investigation Bulletin states that on Fazekas Hill in Budapest's District II there is a quarry facing Torda Street. In the quarry, the Dachstein limestone has a small stone cell in its tectonically pre‑formed fissures, which the nearby residents use as a cellar. The BEAC Nature Hiking Section Cave Investigation Group began exploratory work in the stone mine in 1962, opening a water‑origin cavity system. The group members continued the work on Fazekas Hill in 1963. In about 360 hours they removed 10 m³ of rubble and thus advanced about 10 m. A small accident occurred during the work. Because of the accident the work could have been continued only with insurance, but since they lacked the financial means for this, they temporarily finished the work. They began the geological and mineralogical processing of the site, the precise surveying, leveling and mapping of the area. They will most likely finish the cartographic work in the spring.

The 1964 book titled Geological Excursions Around Budapest mentions that in the large quarry on Fazekas Hill at the intersection of Uzsoki Street and Tordai Street the great corrosive work of water can be observed. The fissures, cracks and even larger cavities in the stone mine, some of which are a few meters deep, walkable in size and generally ending in a dome, indicate that the cracks formed by crustal movements were widened by the dissolving action of surface water.

There are fissures, cavities, caves on the old large limestone mine’s eastern wall. These show the water’s corrosive work in those places where deeper crustal movement previously occurred. Above house number 7 on Uzsoki Street three larger cavities draw attention. One of these leads to the DNy. On the quarry’s western rock wall a stalactite formation can be seen, above which a water intake entrance about 5 m high and 0.6–0.8 m wide is located. Here and in the nearby places it would be worthwhile to carefully excavate to verify whether there are larger cavities, possibly a cave as well. The abundant cave‑like clay debris blocks the way.