Lengyel Pit

The Lengyel Gorge is a spectacular entrance cave located in the Gerecse Mountains within the Danube–Ipoly National Park, in the Gerecse Landscape Protection Area. Deneves also occur in its passages.

Description

The Lengyel cave, situated on the southern edge of the Gerecse, in the outskirts of Tatabánya, on the east‑southeast part of the Kő‑hegy plateau, is about 30 m from a fenced and vertical, axis‑oriented entrance. It is located on flat terrain, in a forest, and has a natural, irregularly shaped entrance measuring 7.5 × 3.5 m.

The gorge‑like entrance shaft is 3.5 m wide and 7 m long. Its base is formed by a scree floor at a depth of 17.5 m. At a depth of 14.5 m a short passage leads to the top of the 7.5 m deep White Shaft. From the base of this shaft a narrow, winding passage with small drops descends stepwise to the lower part of the Flag‑Bell. The bell is 12 m high and has a short side passage at the top. Here beautiful dripstone formations can be observed. From the base of the bell a horizontally extending passage, 0.6–1.2 m wide and on average 0.8 m high, changes direction several times and ends in a narrowing after 17 m.

The cave’s upper Triassic thick‑bedded Dachstein limestone, along the EN‑DNy, ENy‑DK and K‑Ny fault lines, was probably formed by dissolution below the karst water level. Based on its sandy‑gravel fill, it may have later functioned as a short‑term water sink. The air temperature averages around 7 °C, but even in the lower part it varies between 4 °C and 9 °C. This is due to an extremely strong inflowing air current that develops in winter. The carbon‑dioxide content of the air reaches about 5 % in summer and autumn. During heavy precipitation, strong drips and trickles occur. Larger puddles also form at the bottom of the Flag‑Bell and in the terminal passage.

The Gerecse Cave Exploration and Nature Protection Association conducted bat observations in the Lengyel Gorge, during which they determined the presence of 2 bat species; the small mouse-eared bat and the pond bat among the group members. Based on the observation data and the occasionally found fresh droppings, it can be considered an occasional winter bat roost with a small number of species and individuals.

In 1979 the cave was first called Lengyel Gorge in the literature. The Polish word entered its name because of the nearby Polish Cave. The cave also appears in the literature as II. sz. mine (Lendvay 1979), Polish Cave II. sz. mine (Juhász 2007), The Polish Cave II. sz. mine (Lendvay 1979), Polish Cave II. sz. mine (Székely 1994) and Gorge Cave (Lendvay 1979).

Research history

In the 1961 edition of the Karst and Cave Exploration Bulletin, a study written by Norbert Bathó includes the Lengyel Gorge according to the 1979 manuscript of Ákos Lendvay. The study publishes that the direction of one blocked passage of the Polish Cave points to the nearby collapsed II. sz. mine, which was considered the second entrance mine of the cave before the discovery of the eighth level. This hypothesis was also supported by the strong clay blockage appearing on the eighth level and the animal bones found in the clay at that level. In the 1967 edition of the Karst and Cave Exploration Bulletin, according to a publication by Ákos Lendvay, there are two other research sites near the entrance of the Polish Cave, the I. and II. numbered mines. The I. mine is located 80 m from the Polish Cave, the II. mine 170 m away. Both are very unstable, dangerous workplaces, but for the air exchange of the Polish Cave a second, possibly third entrance could probably be uncovered from these mines.

In the 1974 Karst and Cave Research Bulletin it is written that the Fényes Elek Cave Research Group worked in the area of the Lengyel cave from April 8 to 14, 1974. (In the manuscript written by Ákos Lendvay in 1979 it is mentioned that this part of the publication concerns the Lengyel gorge.) According to the group report published in the first half‑year volume of the MKBT Report 1975, the Fényes Elek Cave Research Department dismantled the 1st and 2nd numbered shafts of the Lengyel cave in 1974, but among the debris they managed to reach only 2–3 m deeper by the department members.

The 1979 report of the Kőbánya Cave Research and Mountaineering Department states that near the Lengyel cave, within a roughly 100 m diameter circle, there are two more caves, the Summer cave and the Lengyel gorge. The Lengyel gorge, cave survey number 4630/23, is located about 30 m D from the Lengyel cave. It is a cave chamber opening 7–8 m long, 4–5 m wide and 2.5 m high. The department largely removed the stones that had fallen to the floor. Around 1973 others may also have worked in the cave. The downward‑going trench on the north‑east side was blocked by two huge rock blocks, which the department’s cave investigators reached by blasting behind. The members blasted a fissure up to 4–5 m in length, which continues. It was considered an encouraging exploratory investigation. It was also called the Bathó Norbert and Lendvay Ákos II shaft. Further names of the cave are the Lengyel cave II shaft and Gorge cave (Lendvay 1965).