József-hegyi No 4. Cave

József-hegyi No 4 cave is one of the caves located in the Budai Mountains of the Danube–Ipoly National Park, in District II of Budapest.

Description

The cave is situated on Józsefhegyi Road on József Hill, with a vertical axis entrance that is developed and closed with a steel plate door.

The cave lies between the József-hegyi cave, the József-hegyi 2–3 cave and the Molnár János cave.

In 2009 the cave was called József-hegyi No 4 cave for the first time in the literature. In the literature the cave also appears as József-hegyi 4th numbered cave (Adamkó, Leél-Őssy 2011), József-hegyi/IV. cave (Adamkó, Leél-Őssy 2009) and Kádár cave (Adamkó, Leél-Őssy 2011).

Research history

According to the 2009 report of the Rózsadomb Kinizsi Cave Research and Mountaineering Sports Association, on 13 November 2008, due to replacement of a water‑pressure pipe in front of 11 Józsefhegyi Road in District II of Budapest, an unknown, especially large, 2 m high and 4 × 1.5 m spherical chamber emerged on the road surface, from which warm air flowed intensely. The association cleared the fissure leading down the slope (to K) from the spherical chamber. After 4 m the passage split.

One branch continued gently downwards toward K. The association members excavated this branch for about 7 m. The other branch turned into a series of loose spherical chambers toward DK, and 7 m below the road surface led into a nearly 1 m wide fermentation zone oriented K–Ny‑i. In this zone, next to the rock wall, the members proceeded down almost 2 m, but further excavation was not promising because there was little air exchange.

A passage less than 1 m in diameter is typical on both branches. Only one or two chambers are larger. In the cave, pea‑sized stones were seen in a few places. 2 m from the chamber, to the ENE, in the pipe‑laying trench, the part of the cave called Ágyúcső was discovered during debris removal; it is a gently curving conduit source tube. The 0.8–1.0 m diameter passage was completely filled with clay and debris. Spectacular white calcite crust pieces, 4–5 cm thick and resembling cauliflower, emerged from it. The passage became almost vertical about 3 m deep, in a large chamber. In winter the entrance side facing ENE was very icy. It seemed promising to develop this part of the cave. Richárd Kovács surveyed the cave on 24 November 2009, and using the survey data prepared the cave plan map and a longitudinal section map. According to the survey the cave is 31 m long and 8.5 m deep.

The association’s 2011 report states that it is located on the road section before numbers 11–13 Józsefhegyi út. The cave was discovered by the members in October 2009 during gas‑pipeline laying. After the first examination the cave remained open for more than half a year, during which the ceiling‑side wall of the first chamber collapsed and became dangerously unstable. A large water main pipe was routed over the passages on the Danube side, making the cave unstable. The research permit for the cave was withheld on the recommendation of the Danube–Ipoly National Park Directorate and the association did not receive it. The cave entrance was sealed, and the unstable entrance part was filled with concrete, reinforced and secured. In February 2011 the association began intensive exploration of the cave and removed about 50 m³ of marl, clay and kaolinous debris to the surface.

Although relatively far from the Molnár János Barlang, the association hoped that unexplored passages could be accessed between the two caves. Based on a nearby drilling installed by the association in 1984, the marl is only a few 10 m thick here, so it is probably necessary to dig deeper to discover new passages. The members explored at two end points: partly directly cleaning the hot water breakthrough shaft beneath the entrance, partly at the bottom of the spherical chamber series, deepening the cave under the walkway. At both excavation points they reached about 15 m depth.

Adamkó Péter compiled the floor plan map of the József-hegyi No 4 cave (Kádár-cave) on 19 October 2011, which presents the cave at a scale of 1:53. The map indicates the east direction. According to Groma Klára’s 2011 manuscript, the József-hegyi No 4 cave located in Budapest District II, on the parcel with cadastral number 15153 and cadastral numbers 4762‑77, is 31 m long, has a vertical extent of 8.5 m and a depth of 8.5 m. The association’s 2012 report includes a site plan on which the location of the József-hegyi No 4 cave and the nearby caves can be observed.

In the table listing caves discovered on Rózsadomb and its surroundings since 1995, published in a 2018 issue of Földtani Közlöny and compiled on the basis of the 2017 data of the National Cave Register, it can be seen that the József-hegyi No 4 cave, discovered in 2009 and with cadastral number 4762‑77, is 31 m long and has a vertical extent of 8.5 m. The cave description in the study states that in the summer of 2009 a water pressure pipe was laid on Józsefhegyi út. In the chalky Buda marl a trench opened 1.5 m deep, revealing a spherical chamber 2.5 m in diameter, whose bottom was filled with debris. After removing the collapse, Peter Adamkó, Szabolcs Leél‑Őssy, Csaba Leél‑Őssy, Zsolt Leél‑Őssy and junior Peter Adamkó entered a sloping passage. On the DK side of the pit another large closing spherical chamber opened, beneath which a nearly 2 m diameter, completely filled spring water pipe descends.

At a depth of barely 3–4 m it crosses Józsefhegyi út, and there the initially broken sloping passage splits in two. One branch leads almost vertically downwards among spectacular dissolution forms. This was excavated to a depth of 12 m, but the passage disappears in a clay‑bentonite fill, with no cave draught. Unfortunately, the research pit remained open for more than a year, and the sloping Józsefhegyi road directed precipitation straight here. The cave behaved almost like a water sink and the shaft filled again with a large amount of carried debris. The end of the spring water pipe was lost in the bentonite fill, as was the other excavation point.