Solymári quarry No 1 Cave

The Solymári quarry No. 1 cave is one of the caves located in the Budai Mountains of the Danube–Ipoly National Park, in Solymár, on Zsíros Hill.

Description

From the centre of Solymár, about 2 km to the DNy, near the well‑known and tourist‑map marked Solymári‑Devil’s Hole, under its main entrance and on the side of the large, no longer operating stone quarry, is the Solymári quarry No. 1 cave. It is situated in the Budai Landscape Protection Area. The entrance to the cave is relatively close to the quarry entrance, at the eastern edge of the quarry, in a rock outcrop appearing on the upper part of the bauxite waste dump, at an altitude of 327 m above sea level. The entrance, 1.9 m wide and 0.9 m high, is of natural origin, horizontal in axis direction and of triangular and irregular shape.

The cave, reachable by an easy walk and then on difficult (steep) terrain, was formed in Upper Triassic Dachstein limestone. The freely viewable cave is easily walkable. The cave’s spatial form is of a rock‑tube type. Its slope is horizontal and its characteristic cross‑section type is an ellipse. A dome, a seed‑mirror and a breccia zone are visible in the cave.

In the spherical‑chamber‑like cave there are few mineral formations, only indistinct, corroded calcite crusts, pea‑sized, montmorillonite‑altered, earthy, colourless stalactite encrustations can be observed. The rock mass is very fractured. Next to the entrance there is an externally projecting fault plane, which probably meant that tectonics played a large role in the formation of the cave. Later it was altered by freeze‑thaw rock disintegration. Because of the freeze‑thaw, disintegration processes the cave floor is partly covered by rock debris and partly by a clay (to a lesser extent humus‑containing) filling material. Most certainly corrosion and dissolution processes were the main cavity‑forming factors in the main stage of the cave’s formation. The cave is probably a remnant, a leftover part of an older and larger cave.

Research history

The book published in 1958 titled *Budapest természeti képe* mentions that in Pál Jablonkay’s 1935 book there is a note that at the same level as the Solymári spherical chamber opening, on the quarry wall there are still 6–8 other openings visible. According to Sándor Láng these have since been excavated and openings of karst passages can be observed at other points. Based on the openings in the quarry wall, Pál Jablonkay thought that there was once a polje here. Sándor Láng says this is impossible based on the surface forms.

In the manuscript completed in 1976 and written by Károly Bertalan it reads that the solymári quarry gas source vents are located on Solymár in the Buda Hills, on Sziklás Hill. These are situated in the quarry beneath the Solymári Devil's Hole. The vents were discovered by the exploitation of the mine. The part of the manuscript concerning the gas source vents was written based on two literary works. In the national cave list of the book *Caves of Hungary* published in 1984, the summary name Solymári quarry gas source vents appears among the caves of the Buda Mountains. Related to the list, the geographic location of the caves of the Dunazug Mountains is shown on a 1:500 000 scale map, which displays the geographic location of these cavities.

Attila Gazda surveyed the cave and, using the survey data, on July 19 2004 compiled the floor plan map, longitudinal section map and cross‑section map of Solymári quarry No 1 cave (Solymár, cave‑cadastral unit 4773). The maps present the cave at a scale of 1:100. The map sheet marks the east‑west direction. On the floor plan map the longitudinal and cross‑section positions in the cave can be observed.

Attila Gazda wrote the cave register sheet for the National Cave Register on August 16, 2004. The register sheet states that the Solymári quarry No. 1 cave is located in Solymár, Pest County, in the Buda Hills, in cave cadastral area 4773. The cave entrance is in a quarry, in a rock pit, at an altitude of 327 m a.s.l. The surveyed cave is 2.6 m long, 2.6 m horizontal extent, 1.4 m vertical extent, 1 m high and 0.4 m deep. The mineral deposits of the slightly altered cave are practically intact. Its floor is trodden, deepened. Csaba Egri prepared the cave photographic documentation for the National Cave Register on August 25, 2004.