Cadernos Lab. Xeolóxico de Laxe Coruña. 2013. Vol. 37, pp. 11 - 36 ISSN: 0213-4497

Geological sketch and the non-karstic caves of the Mountains in

ESZTERHÁS, I.1 and SZENTES, G.2

(1) Köztársaság út 157, H-8045 Isztimér, Hungary, [email protected] (2) Alte Frankfurter Str. 22 b, D-61118 Bad Vilbel, Germany, [email protected]

Abstract

The about 4000 km2 Bakony Mountains form the most extensive region of the Trans-Danubien Mountains between and Marcal River. They have a typical medium relief, including plateaux of various heights, and denudated fault blocks interspersed with inter mountain basins. In the southern and western areas of the mountains, basalt cones and basaltic sheets are frequently found. In the central area, the variously sloping landscape is inclined towards the blocks. Limestone and dolomite predominate, and there are extensive karst regions and numerous karst caves. Of course, from the point of view of the non-karstic caves, these regions are insignificant. Significantly smaller is the occurrence of quartziferous (sandstone and conglomerate) and basalt rocks, however 147 non-karstic cave are known in these rocks and, in addition, 35 artificial cavities, considered as caves, are listed. The authors describe the geology, the geomorphology and the non-karstic cave development of the Bakony Mountains. Furthermore, typical examples of the caves have been selected and presented according to the different rock formations and development types.

Key words: sandstone; geyserites; gas bubble; explosion cave; geyserite cave; tectonic cave; atectonic cave; break down cavity; consequence cave; talus cave; cavity between basalt columns; alkaline solution cave; ice cave; flooded cave.Abstract 12 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

INTRODUCTION As a result of systematic research by the Volcanspeleological Collective, 147 natural The Bakony Mountains form a section non-karst caves and 35 artificial cavities of the 4000 km2 of the Trans-Danubien have been listed in the Bakony Mountains. Mountains between Lake Balaton and Fifty-six non-karstic caves have developed Marcal River. They have a typical medium in basalt. Forty-one caves are listed in the relief, including plateaux of various heights, geyserite of the Tihanyi Peninsula. Thirty- and denudated fault blocks interspersed with two non-karstic caves appear in the Miocene intermontane basins. In the southern and calcareous conglomerate and 10 caves are western areas of the mountains, basalt cones known in the Pannonian quartziferous and basaltic sheets are frequently found. sandstone. Furthermore, 7 caves have In the central area, the variously sloping developed in basaltic tuff and one in loess. landscape is inclined towards the blocks. Artificial cavities have generally been dug in Limestone and dolomite predominate, basalt tuff and loess (Fig. 1). and there are extensive karst regions and The present study intends to summarize numerous karst caves. Of course, from the the development of the non-karstic caves point of view of the non-karstic caves, these and to demonstrate their speleological regions are insignificant. significance. CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 13

Fig. 1. Location of the non-karstic caves or the clusters of non-karstic caves in the Bakony Mountains

SKETCH OF THE GEOMORPHOLOGY Mountains and the Balaton Upland. Other less significant areas of the mountains are The Bakony Mountains make up the Keszthelyi Mountains, the the most extensive region of the Trans- Basin and the Bakony Foreland (Fig. 1). The Danubien Mountains (3974 km2) which Northern and Southern Bakony Mountains extends from the Zala River Valley to the are divided by the Veszprém- Móri Trench and from Lake Balaton to Trench, while the Veszrém – Ngyvázsony the . The mountains Trench separates the Southern Bakony are divided into three main areas along Mountains and the Balaton Upland. The NE–SW trending fault lines, the Northern Tertiary and Quaternary uplifts formed Bakony Mountains, the Southern Bakony the present elevation of the region. Young 14 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

tectonic movements uplifted the land more buried limestone layers. Fertile basins are and more towards the north. The highest also to be found in the western area. An point of the mountains is Mount Kőris unusual surface formation, an altiplanation 701 m above the sea level, which rises in the surface, is the “Stone Sea” in the Kali Basin, north of the region. The main constituents whilst Castle Hill at Sümeg, a western block of this region are the karstic limestones and of the Southern Bakony, is composed of dolomites. Many characteristic surface and Cretaceous limeston. subsurface karstic forms are to be found in The Keszthelyi Mountains, the the covered and in the opened karst regions westernmost part of the Bakony Mountains, (JUHÁSZ, 1987). are adjacent to the Balaton Uplands. The The Northern Bakony Mountains make mountains consist of limestone and dolomite up the the highest and most extensive area in blocks, which are bordered on either side by the region. The land itself is a forest covered steep multiple faults. Between the blocks karst, which is dotted with many romantic several small basins are to be found. In the valleys. The creeks eroded the covering north-western part of the basalt formation gravel sheet and have cut deep canyons into the Mount Tátika Group occurs. the underlying limestone or dolomite. The The volcanic series of the Balaton largest basin is the loess covered Zirci Basin, Upland is an intra-plate monogenetic which is surrounded with the large blocks of volcanic formation. The volcanic landforms the Northern Bakony Mountains. Surface are composed of denudated maars, tuff water occurrence is insignificant, therefore, rings, spatter cones, lava lakes, valley- settlements are to be found only near the filling lava flows and lava fields. The basalt karst springs. The easternmost parts of has broken through and covered the loose the mountains are the Tési Plateau and the Pannonian sediments of the Tapolca Basin. Bodajki Block. This is a karst region with The overlying hard basalt trap has prevented creeks and dry valleys, with barren rock denudation and thus has developed witness surface and patches of forest with sinkholes buttes. In some witness buttes, for instant and caves. on Mount Szent György, spectacular Southern Bakony is surrounded by the columnar basalt forms occur. Volcanic towns of Veszprém – Devecser - Sümeg and activity has played an important role in Tapolca. The eastern part, the Veszprémi the formation of the Tihanyi Peninsula. Plateau, is a barren dolomite plateau from The Inner Lake and the Outer Lake are the 250 to 300 m above sea level. In the western apparent remains of two calderas (BUCKÓ, part limestone is dominant and contains 1970). Several hundred geyser cones have many diverse karstic features. South of developed as a result of postvolcanic activity the Séd Valley a layer of gravel covers a (CHOLNOKY, 1931). The base formation basalt plateau. The 601 m high Mount Kab of the peninsula is the yellowish white and Mount Agár are the most extensive Pannonian sand and clay, which crops out in stratovolcanoes in the region. The basalt is the steep banks of the Lake Balaton. In the underlain by limestone and pseudokarstic postvolcanic period erosion has significantly depressions which appear on the basalt denuded the volcanic forms themselves surface due to karstic corrosion of the and revealed the fossil surface beneath the CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 15

Pannonian sediments. Recent valley patterns Hauptdolomite. In the Northern Bakony and alluvial fans have developed over the Mountains, the Dachstein Limestone complete Bakony Mountain range. appears in a narrow belt. The Lower- the Middle- and the GEOLOGICAL SETTINGS Upper Jurassic formations are to be found throughout over in the Bakony Mountains. The Bakony Mountains are basically Limestone and marl series are typical of the composed of sedimentary rocks, which Lower Jurassic among others on the Tési have been superimposed by young basaltic Plateau. Also associated with the Lower formation and geyserite in the Tihanyi Jurassic period it is the black shale-related Peninsula (GYALOG, 2005). manganese ore deposit near the village of The oldest formation is the Ordovician Úrkut. The red ammonitic limestone is a and Silurian series of phyllite and clay schist typical Middle Jurassic formation in the near the village of Alsóörs in the Balaton central region of the mountains. Limestone Upland. series also occur in the Upper Jurassic. Permian red sandstone and conglomerate Cherty limestone was deposited in the overlie the folded Palaeozoic bedrock with Lower Cretaceous period in the Zirci Basin. angular unconformity. Large Permian Limestone was deposited in the Middle outcrops are to be found in the eastern part Cretaceous period. In the Upper Cretaceous of the Bakony Mountains and in the Balaton marl, claey marl and coal seams formed near Upland. The thickness of the formation is the settlements of and Csehbánya. A some 800 m (JUHÁSZ, 1987). unique formation, which is economically The Triassic sequences have typical important, is the Lower Cretaceous bauxite, classical stratigraphy. The Lower Triassic which occurs extensively in the central strata are composed of clay shale and marl region of the mountains. layers interspersed with thin laminated In the Eocene, terrestrial red clay is limestone and dolomite. This formation overlain by coal measures in the Northern can be observed in the Southern Bakony Bakony Mountains, which are, in turn, Mountains and in the Balaton Upland. In overlain either by Eocene Nummulites the Middle Triassic, thick bedded dolomite Limestone or by algal carbonate platform has been deposited, associated to a lesser sediments. The Nummulites Limestone often extent with limestone. This dolomite forms overlays the bauxite deposits (GYALOG, the Veszprémi Dolomite Plateau. Near 2005). Allothigene bauxite accompanied the town of Balatonfüred, light coloured by marl and claey marl has deposited in the drab, bedded, nodular Füredi Limestone is Oligocene. characteristic, which reflects a basin facies The Miocene sedimentary sequence is development. The Upper Triassic thick either basin fill in the intermontane basins or bedded limestone and dolomite are to be occurs in the rims of the basins. Coarse sand found throughout the Bakony Mountains. and conglomerate together with calcareous The most prevalent and thickest rock is a sandstone form the Lower Miocene in the carbonate platform formation, the thick Eastern Bakony Mountains, which is overlain bedded, light grey Great Dolomite or by claey, sandy coal seams in the Várpalotai and 16 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

Szentgáli Basins. Extensive Lajtha Limestone various basalt tuff outcrops are to be deposits represent the Middle Miocene in found. As a result of numerous phases of both the Western Bakony Mountains and in volcanic activity, the thickness of the basalt the Tapolcai Basin. Coarse-grained calcareous formation varies from 50 to 200 metres. In sandstone and conglomerate are to be found the crater basins and in the depressions of in the central and southern part of the the tuff rings, oil shale occurs, originating mountains, and are significant as regards non- from the algae which have settled there. karstic cave development. The post volcanic activity has created the The topset beds of the basins are limnic geyserite in the Tihanyi Peninsula. The sandy and claey sediments, which were basalt, basalt tuff and the geyserite are the deposited in the Upper Pannonian Stage of most significant of the rocks surrounding the Pliocene. In some places, quartziferous the non-karstic caves in the Bakony sandstone occurs, which is suitable for non- Mountains (Fig. 2). On the mountain sides, karstic cave development. accumulated loess is the most characteristic In the Upper Pannonian, intensive formation from the Pleistocene. The basalt volcanism has occurred, which soft deposit offers a suitable material to has resulted in alkaline basalt and basalt construct artificial caves and cellars, but tuff. Occasionally the basalt structure is one natural cavity is also known in the scoriaceous. The witness buttes and tuff loess. rings in the Tapolcai Basin and the basalt Colluvium, redeposited tuff, fluvial sand plateau of Mount Kab embellish the and pebbles together with swamp deposits basalt landscape. In the Balaton Upland, such as turf were deposited in the Holocene.

Fig. 2. Geological map of the surrounding rocks of the non-karstic caves in the Bakony Mountains CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 17

NON-KARSTIC CAVE DEVELOPMENT to show the diversity of the non-karstic IN THE BAKONY MOUNTAINS caves. Up to 2011, 147 natural non-karstic caves and 35 artificial cavities have been The petrographic structure of the listed in the Bakony Mountains. The total mountains is very varied. As a consequence, the length of the natural non-karstic caves 1000 caves which are to be found show diverse is 991 m. The longest caves are the 151 m appearance and development (BERTALAN, long Pulai Basalt Cave (Fig. 6, Pict. 4), 1958; ESZTERHÁS, 1983, 1984). The the 72 m long Halász Árpád Cave (Fig. 8) majority of the rocks are karstic limestone and the 51 m long Kapolcsi Pokol Hole and dolomite, therefore, approximately 85% (Fig. 5, Pict. 3). Eighty-four non-karstic of the caves are karstic. The most significant caves have developed in sedimentary rocks karstic caves are the 4000 m long Csodabogyós such as sandstone, conglomerate, geyserite Cave, the 3600 m long Alba Regia Cave, the and loess, while 63 caves have formed in 2400 m long Cserszegtomaji Well Cave and basalt and basalt tuff (ESZTERHÁS and the hydrologically important Spring Cave of SZENTES, 2004, 2009, 2010). Héviz. The nonkarstic caves according There are also numerous non-karsic to their development can be classified caves. Within the framework of this study into 16 genotypes with four categories we cannot describe all of these caves. We (ESZTERHÁS, 1993; OZORAY, 1960; only intend to present some examples SZENTES 2010) (Table I.). 18 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

Genotypes of the Caves Examples:

I. Syngenetic caves

1. Gas bubble cavities Gas bubble cavity in the Castle Hill of

2. Explosion Caves

a) steam explosion caves Explosion Cave near the village of Gödrös

3. Caves in geyserite. Tihanyi Spring Cave

II. Postgenetic Caves

1. Caves originated through mass movement

a) Tectonic caves - Caves formed parallel to the rim of the Kapolcsi Pokol Hole outcropping rock - Caves developed perpendicular to the rim Lower Cave of Kőudvar of the outcrop - Caves formed along the downcast faults of Pulai Basalt Tuff Cave the basalt layers b) Atectonic caves Vadlány Hole

c) Break up Caves Pulai Basalt Cave Basalt Quarry Cave near the village of Badacso- d) Consequence caves nytomaj e) Talus caves Little Sárkány Ice Cave

2. Fragmentation caves

a)Caves originated through temperature and moisture variation

- Fragmentation caves Kő-hegyi Cave

- Cavities between basalt columns Lépcső-menti Cave

3. Caves originated through chemical weathering Upper Hole of the Aranyház Geyser Cone in a) Alkaline solution caves Tihanyi Peninsula III. Complex cave development

Gas bubble + Artificial Halász Árpád Cave

Geysirite deposition + Alkaline solution Csúcs- hegyi Spring Cave in Tihanyi Peninsula

IV. Artificial cavities Cave Monastery in Tihanyi Peninsula

Table I.: Genotypes of the non-karstic caves in the Bakony Mountains CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 19

The syngenetc cavities, which formed developed concurrently with the geyserite concurrently with the processes of the rock deposition on the Tihanyi Peninsula. Only formation, belong to the first category. Three the central part of the geysirite, caves are different types of syngenetic caves occur in syngenetic, their further cave development the Bakony Mountains. Three gas bubble due to alkaline solution. Unfortunately, 20 cavities open in the Castle Hill of Szigliget geyser cones with caves were demolished for and on Mount Kab. Four caves are the result building material in the first part of the 20th of a steam explosion and 41 caves have century.

Table I.: Genotypes of the non-karstic caves in the Bakony Mountains Fig. 3. Survey of the Kő-hegyi Cave 20 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

Fig. 4. Survey of the Tihanyi Spring Cave CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 21

Fig. 5. Survey of the Kapolcsi Pokol Hole 22 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

Most of the non-karstic caves have formation, and caves have formed along the postgenetic origin and show various downcast faults of basalt layers. Twenty- genotypes. one tectonic caves have formed parallel The tectonic caves originated through to the rim of the outcropping rock in the mass movement, and were formed as a Bakony Mountains. The most significant result of the shifting of the rock masses. are the 51 m long Kapolcsi Pokol Hole (Fig. Thirty-four tectonic caves are known in 5, Pict. 3), the 39 m long Remete Cave near the Bakony Mountains. The basalt surface the village of Zalaszántó and the 26 m long forms steep rims, because of the intense Araszoló Cave. Twelve tectonic caves have denudation of the surrounding sediments. developed perpendicular to the rim of the As a consequence of that, the basalt layer outcrop. The denudation of certain parts lost the support and cracks are forming of the basalt rims varies. The blocks which in the basalt. The cracks develop into denudate faster, down fault and separate caves after the further denudation of the themselves from the neighbouring basalt sediments. Finally, some rims break down layers, forming perpendicular faults to the and collapse. Three different orientations rim. The dilatation of the dominant faults of the potential cave developing cracks results in this type of tectonic caves. Such can be distinguished, in consequence of caves include the Lower Cave of Kőudvar, that three different types of tectonic caves the Gyöny-tavi Cave near the village of are to be found. These are the caves which Köveskál and probably the partly collapsed have developed perpendicular to the rim Bél-féle Sárkány Cave. The Pulai Basalt Tuff of the outcrop, caves which have formed Cave has formed by the downcast faults of parallel to the rim of the outcropping rock basalt layers.

Pict. 1. Entrance to the Csúcs-hegyi Spring Cave in the geyser cone CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 23

Atectonic caves were formed by the Kőkamra and the 7 m long Basalt Street dilatation of the cracks as the rock mass Niche. moved down the slope. Five of these caves Break up Caves form when the roof of a can be observed in the Basalt Street on cavity loses its stability and collapses partly Mount Kovácsi. From the rim, basalt blocks or completely due to the lower layers being have separated off, and are sliding down on washed out. The original cavity becomes the convex slope of the sandstone and marl filled with debris and in the upper part surface. The sliding induces cracks in the develops a new hollow, the so-called break basalt blocks, which can widen into cave up cave. The most significant break up size as they slide further. Caves originating cave in the Bakony Mountains is the 151 from such dilatation are the 24 m long m long Pulai Basalt Cave (Fig. 6, Pict. 4) Vadlány Hole (Fig. 7. Pict. 5.), the 12 m long (ESZTERHÁS, 1986).

Pict. 2. Remains of the Explosion Cave of the Castle Hill of Szigliget

The consequence caves are a particular holes in the higher elevations of a system. example of caves which have originated In the Bakony Mountains, only one through collapse. The natural collapse of consequence cave is known, the 3 m long ceilings in artificial cavities (mine, cellar, Basalt Quarry Cave near the village of dungeon) may form apparently natural . 24 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

Pict. 3. Kapolcsi Pokol Hole

Pict. 4. Pulai Basalt Cave, in the background disc-shaped isingerit can be seen on the wall CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 25

Three talus caves represent the hegyi Cave (Fig. 3) near the village of pseudocaves in the Bakony Mountains. The Szentbékálla, in the Kerek-kő Cave near Little Sárkány Ice Cave and the Big Sárkány the settlement of , which has Ice Cave on Mount Szent György and the developed in sandstone and in Northern Gyöngy- tavi Pseudocave near the village Cave near the village of Ajkarendek which of Köveskál are to be found between the has formed in conglomerate. The specific accumulated basalt blocks below the basalt fragmentation of the basalt forms cavities rims. between basalt columns. These are narrow, Fifty-four caves have developed through high caves or shafts. Seventeen cavities fragmentation in the Bakony Mountains. between basalt columns are listed among the Fragmentation through temperature and basalt columns of the rims. In Mount Szent moisture variation attacks the basalt, the György, the Lépcső-menti Cave (Pict. 7) and sandstone and the conglomerate, which the Kilátó-alatti Cave, in Mount Badacsony results in smaller caves and rock shelters. the Hedera Cave, the Cirmos Cave and in Thirty-seven caves have formed through Mont Somlyó the Sziklakonyha Cave are typical fragmentation. The rock forming to be found between the basalt columns. In minerals react to altering physical influences Mount Tátika, the Fekete-oszlopos Cave (temperature, moisture) with different has formed between the basalt colums which volumetric expansions, which cause tiny have slid apart. In the Bakony Mountains, it cracks, then holes which occur in the is difficult to separate the cave development place of fragmenting minerals. These type originating from altiplanation, from that of fragmentations are to be found in Kő- origination from fragmentation.

Pict. 5. Basalt blocks in Vadlány Hole 26 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

Fig. 6. Survey of the Pulai Basalt Cave CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 27

Chemical weathering has resulted in of the organic acids. Alkaline solution has the formation of different types of solution been partly responsible for the formation caves. Acidic solution, which forms cavities of what were originally syngenetic geysirite in karstic rock, is not the subject of the caves in the Tihanyi Peninsula. The geysirite present study. The non-karstic rocks (basalt, formation is diverse as regards the deposition geyserite, sandstone) contain large amounts and the chemical reactions of the solutions. of silicate. In the nature, the resulting acid can The precipitated and consolidated silicate not dissolve the siliceous material. Solution (geysirite) dissolves, if the pH value of the is only possible in an alkaline environment. solution exceeds 8. Accordingly, solutions The lye on the surface or in the subsurface over pH8 produce geyser activity in the 41 zone can originate from postvolcanic geyserite caves alkaline solution occurred activity or, rarely, from the decomposition (ESZTERHÁS, 1987-b).

Fig. 7. Survey of the Vadlány Hole 28 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

Another cave development category is formation, the “Stone Sea” of Mount Kő is the complex cave development. It is possible to be found at 207 m above the sea level to in each individual caves to detect several the west of the village of Szentbékálla. Here cave forming factors. Nevertheless, it is the most characteristic rock figure is the necessary to create a category where the Kelemen Stone. The covering rock slab of presence of several cave forming factors are the stone formation is subject to movement. approximately equivalent. In this case, it is The 2.5 meter wide and 90 cm high entrance difficult to define the main factor. Such a to the Kő-hegyi Cave (Fig. 3.) opens in the cave is the 72 m long Halász Árpád Cave south-western side of Kelemen Rock. The (Fig. 8) on Mount Kab. The cave is partly cave is a 3.25 m long gradually narrowing, artificial because a series of gas bubble lenticular niche. The surrounding rock cavities have connected to the tunnel of a is Pannonian siliceous sandstone. The mining company. We can also include here cementation of the sandstone is uneven. the geysirite caves in the Tihanyi Peninsula, The fragmentation of the loosest part of the which have formed partly syngenetically sandstone has resulted in a cave. with geysirite deposition and partly In several locations of the Bakony postgenetically by alkaline solution. Mountains, calcareous or siliceous Some artificial cavities are considered conglomerate occurs. Thirty-two small to be caves by the local population. In the caves are known in conglomerate formation. Bakony Mountains, 28 cave-dwellings in Mount Ajka near the village of Ajkarendek loess have been listed. Nineteen of these is composed of Miocene marly limestone, cave-dwellings have collapsed, only 9 which is overlain by Upper Pliocene cavities of the Tatár Holes near the village marly, limy quartz and limestone pebble of are still in existence. In the conglomerate. Three caves are to be found in Peninsula, a Cave Monastery was the conglomerate at the boundary between carved in the basal tuff nine centuries ago. the two rock layers. The most characteristic Seven cavities of the monastery can still be is the 6.5 m long crawling passage of seen. Northern Cave. The cave development began DESCRIPTION OF SOME CHARAC- with the formation of a cavity through the TERISTIC CAVES ACCORDING TO THE loosening and eroding of the underlying TYPES OF CAVE DEVELOPMENT AND sediments. The resulting small cavities in the THE SURROUNDING ROCK fragmented conglomerate, gradually formed into larger cavities. The present study has selected and Geysirite occurs mainly on the Tihanyi reviews the 18 most significant and Penninsula. Smaller outcrops of geysirite characteristic caves of the 147 natural non- are located in the Koloska Valley and karstic caves and 35 artificial cavities in the near the village of Pula. It is reputed that Bakony Mountains. originally 130 – 150 geyser cones existed on Ten caves open in sandstone. Each of the Tihany Peninsula. Seventy-nine cones the 10 sandstone caves have developed by were identified in 1983, but many of them fragmentation through temperature and were partly demolished (ESZTERHÁS moisture variation. A peculiar surface 1987-b). Since the development of the CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 29

geyserites, caves are dependent on the geyser We describe the most characteristic ten cones, many of these caves are the victims basalt caves. of quarry operations. Recently, 22 geyserite Two gas bubble cavities formerly caves or the ruins of geyserite caves were existed in the basalt dyke of Castle Hill at identified. The most important caves are the Szigliget Village. One of the cavities has Csúcs-hegyi Spring Cave and the Tihanyi been completely demolished. The remains Spring Cave. of the other cavity in columnar basalt, the The Tihanyi Spring Cave is a gated so-called Explosion Cave of Castle Hill of show cave (Fig. 4). The fourteen metre long Szigliget (Pict. 2) still exists (ESZTERHÁS, cave is composed of two chambers and two 1987-a). The surface of the bell shaped, 130 bigger niches. The walls are decorated with cm long hole is perfectly smooth. An 85 cm spectacular solution forms, which also form long syncline in the foreground indicates the vault of the ceiling. In the first chamber, the original 215 cm length of the cavity. At two striking joints and a layered hydro- the end of the hole, a 5-6 cm diameter tube quartzite formation overlain by compact dipping down at an angle can be observed, limy-siliceous geyserite can be observed. which probably marks the place of inflow of Some solution forms are covered with the blowing gases. secondary calciferous coatings. Near the cave The 51 metre long Kapolcsi Pokol Hole entrance and in the second chamber, walnut (Fig. 5, Pict. 3) has formed parallel to the rim and apple-sized opal concretions can be seen. of the outcropping basalt (ESZTERHÁS, The artificial widening in the cave crops out 1984-a, 1985). The basalt is underlain by a nicely the structure of the geyser cone. loose sandstone layer and its rim has broken The Csúcs-hegyi Spring Cave (Pict. 1) away. The basalt blocks have not slid down opens in the Tihanyi Peninsula in the western on the slope, but leant against the bedrock, side of Mount Nyereg. The entrance to the forming a tectonic cave, which is parallel cave is 3.2 m high and 2.7 m wide. Behind to the verge. In the sandstone, thick basalt the entrance runs a 4.2 m long and 3 m wide blocks dam up the seeping water, which oval chamber. There is no vaulting, in the emerges in the cave as a spring. This spring wall only minor salient and flares appear. feeds a small lake. The size of the lake varies, From the chamber a 6.5 metre high and because after the water reaches a certain 20 – 25 cm diameter chimney opens to the level a siphon system drains it. surface. Between the chimney and the cave On the western slope of Mount Tátika entrance a 4.3 m high blind chimney rises. there is a similar original tectonic cave, the The surrounding geysirite is made up of 39.2 m long Remete Cave. Behind the 1.2 cellular hydro-quartzite with minor lime m wide and 3 m high entrance a gradually content. Compact chalcedony occurs in a narrowing, funnel-shaped corridor leads 3-4 m section of the chamber. On the hydro- to the high and narrow main passage. The quartzite surface solution forms, there are vertical extent of the cave is 20.4 m, but traces of the cave having developed in an the average width is only 40-50 cm. The alkaline solution. cave wall is composed of columnar basalt. Fifty-six caves have formed in the The basalt columns are coated with white alkaline basalt in the Bakony Mountains. calcite speleothems, which stems from the 30 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

overlaying calcareous sand (ESZTERHÁS, The atectonic Vadlány Hole (Fig. 1987-a). 7, Pict. 5) is the most remarkable cave The Lower Cave of Kőudvar is to be on the Mount Kovácsi. The irregular found also in Mount Tátika. Behind the 1 quadrangular entrance shaft to the cave is m high and 60 cm wide entrance runs a 5.1 a 45 degree slope, which is divided into two m long crawling passage. The significance of openings by a jammed rock slab. Beneath the cave is the perpendicular development to the shaft a 2.7 m wide chamber opens out, the rim of the basalt outcrop (ESZTERHÁS, which continues in a 6.8 m long, 1 m wide 1988-a). and 2 – 2.8 m high rectangular Entrance The 151 meter long and 21 m deep Pulai Passage. The walls are composed of Basalt Cave (Fig. 6, Pict. 4) is a break up cave fragmented gray basalt. The cave belongs (ESZTERHÁS, 1985). The 25-30 m thick to the atectonic development group of basalt is underlain by soluble limestone. the postgenetic caves (ESZTERHÁS, Along the cracks in the basalt, seeping 1988-b; OZORAY, 1960; SZENTES, water has dissolved holes in the limestone, 1971). The depths of the cave have formed into which the basalt layer has broken. The concurrently with the Basalt Street on the cave is accessible through a narrow shaft, surface. The basalt layer lost its support, which leads to a bigger chamber. From tipped out and slid down on the concave this chamber various small passages and slope. This movement has generated shafts open in different directions. The parallel and perpendicular expanding cave wall shows nicely the different basalt cracks to the main strike of the Basalt layers, which are the witness to the several Street. One of the perpendicular cracks thousand years of volcanic activity. In the forms the longitudinal extent of the cave cave, a rare silicate mineral can be found, the and several smaller parallel cracks can be disc-shaped isingerit. observed in the wider parts of the cave. CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 31

Pict. 6. Ice formations in summer in Big Sárkány Ice Pict. 7. Lépcső-menti Cave between the basalt Cave columns in Mount Szent György

The Basalt Quarry Cave near the village enough to form an ice crust on the basalt of Badacsonytomaj is to be found in the wall blocks. The speed of the outward flowing of an abandoned basalt quarry. The cavity air is 5 – 15 m/sec, which spasmodically is a 5 m wide and 2.4 m high niche. The speeds up sometimes in every few minutes. embayment of the hole is 2.9 m. The small In winter, the inflowing air does not cause cavity is the only consequence cave in the ice coating. Nearby, in the 31 m long Bakony Mountains. The hole was created by Big Sárkány Ice Cave the ice coating can a break down during quarry operation. similarly be observed (Pict. 6). The Little Sárkány Ice Cave opens on The cavities between basalt columns the northern side of Mount Szent György are specific fragmentation caves of the between the debris of collapsed basalt basalt rims. With favourable climatic and columns (ESZTERHÁS, 1994-b). The petrographic conditions the basalt rim can entrance to the cave is 2 m wide and 1 m sometimes form 20-30 m high columns. The high. The zigzag labyrinth is passable for fragmentation results in single columns, a length of 6.7 m. The cave is a so-called which collapse later in the ultimate stages of dynamic ice cave. In the summer season their development. If the gravel can trickle (March-September), the temperature of the from between the gaps in the columns, outward flowing air is below freezing point, then high, narrow cavities form. Seventeen therefore, the condensed water gets cold cavities between basalt columns have been 32 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

listed in the Bakony Mountains. Most of the year, only in a very dry summer of them are to be found on Mount Szent is 20-25 m passable in the upper section. György, for instance the 37 degree sloping, A complete study was carried out in the 2.3 m long and 7.6 m high Lépcső-menti year 1987, after pumping the water out Cave (Pict. 7). from the cave. The results have not clearly One of the most significant non-karstic proved the origin. Probably, the holes were cave in the Bakony Mountains is the Halász a range of gas bubble cavities, which were Árpád Cave (Fig. 8). Halász Árpád was a connected artificially during the mining geologist and cave explorer in the region. operation and were used as a shelter and a The cave is a 72 m long horizontal passage store. In some places on the wall ropy lava 4-5 m beneath the surface. Two shaft formations and conical lava speleothems entrances lead to the cave (ESZTERHÁS can be seen. After the mining operations 1988-c). The cave is filled with water up were abandoned, groundwater has filled up to the entrance shafts for the greater part the cavities.

Fig. 8. Survey of the Halász Árpád Cave

In the basalt tuff, 7 caves have been with 3-4 mm sized calcite pizolites, which listed. The most interesting is the Explosion have been completely looted. The cave Cave near the settlement of Gödrös. The 3 has developed through steam explosion m high and 1.5 m wide entrance to the cave (ESZTERHÁS, 1988-c). Due to a opens in the wall of an abandoned quarry. decrease in pressure, the streaming hot The 6.5 m deep cave is a 16 m long maze. water, which was of volcanic origin and The basalt tuffite walls were decorated travelling upwards, suddenly volatilized. CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 33

The consequent explosion stretched apart had no surface connection, was opened by the loose, pyroclastic rock. In this way, an quarry operations in 1930. irregular-shaped hole was formed which The Pulai Basalt Tuff Cave opens near the was filled with a hot solution. From this highway between the towns of Veszprém and solution precipitated minerals cemented the Tapolca. The 10 m long low, but wide crawling walls of the hole and deposited the calcite passages of the cavity have been formed by pizolite coating. The cave, which originally the downcast faults of basalt layers.

Fig. 9. Survey of the No. 2 Monk’s Dwelling in the Tihanyi Peninsula 34 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

Pict. 8 Monk’s Dwelling in Tihanyi Peninsula

As well as the 35 artificial cavities was devastated by collapses and looting. in the Bakony Mountains it is worth Recently, as a scheduled monument, the considering the Cave Monastery, the so- ruins have been partly renovated. called monk’s dwellings (Pict. 8.), which Near the village of Balatonkenese there have been carved in the basalt tuffite of the were once 28 holes carved in the loess Tihanyi Peninsula (ESZTERHÁS, 1987- wall, but today only nine cavities remain. b; MEDNYÁNSZKY, 2009). The No. 2 The local people call them Tatár (Tartar) Monk’s Dwelling (Fig. 9) is a complex hole. Holes, however, their origin most probably The base area of the 3 m high main chamber is not from the age of the Tartar Invasion is 6 x 3.5 m. Behind the chamber a 2.5 x 1.3 (1241-42), and this is just a folk tale m sized cell opens where a carved grave is to (MEDNYÁNSZKY, 2009). The cavities be found in the bottom. In the MiddleAges, were mentioned first in the year 1676. The between the years 850 and 1350 active biggest hole is the No. 7 Tartar Hole. The religious life took place in the monastery. hole consists of two chambers, one 6 m long Orthodox hermits from Greece lived here, and the other 5 m long. Memorials and wall and hollowed out their reclusories, chapel scrapes identify many cavity-dwellers and and dining-room. Later, the monastery at the present time the hole is used as an was abandoned and through the centuries occasional bivouac place. CAD. LAB. XEOL. LAXE 37 (2013) Geological sketch and the non-karstic caves 35

SUMMARY Értesítő (48. köt. 1. füzet), Budapest p. 225- 227. The Bakony Mountains are the most ESZTERHÁS, I. (1983). A Bakony complex geological region in Hungary. barlangjai (Caves of the Bakony The mountains are composed of numerous Mountains) - in Mészáros: Bakony, sedimentary (chemogenic, clastic, and Balaton-felvidék - Medicina Könyvkiadó, biogenetic) and volcanic (basalt and basalt Budapest p. 45-71. tuff) rock formations. As a consequence, ESZTERHÁS, I. (1984). Lista a Bakony the speleology of the region is diverse. barlangjairól (List of the Caves in There are a large number of horizontal the Bakony Mountains) - Folia musei and vertical, wholly or partly flooded, cold historico-naturalis Bakonyiensis, p. or thermal water originating karstic caves. 13-30. The non-karstic caves, which number 147, ESZTERHÁS, I. (1985). A Kapolcsi Pokol- have developed through gas bubble, steam lik (The Kapolcsi Pokol Hole) - Folia explosion, and geyserite deposition. There musei historico-naturalis Bakonyiensis, are also tectonic, atectonic, break up, Zirc p. 39-42 talus, fragmentation and alkaline solution ESZTERHÁS, I. (1986). A Pulai- originating non-karstic caves. Some of bazaltbarlang és környéke (The Pulai them are flooded and two of them have ice Basalt Cave and its surrounding)- Karszt coating. és Barlang (I. füzet), Budapest p. 23-32. ESZTERHÁS, I. (1987-a). A Bakony BIBLIOGRAPHY bazaltbarlangjai (Basalt Caves in the Bakony Mountains) - Föld és Ég (22. évf. BERTALAN, K. (1958). Magyarország 12.sz). Budapest p. 360-364. nem karsztos eredetű barlangjai (Non- ESZTERHÁS, I. (1987-b). A Tihanyi- karstic Caves of Hungary) - Karszt- és félsziget barlangkatasztere (List of the Barlangkutatási Tájékoztató (jan-jún), Caves in the Tihanyi Peninsula) – Ba- Budapest: p.13-21. kony Természettudományi Kutatásának BUCKÓ, E. (1970). A Tihanyi-félsziget Eredményei (18. köt). Zirc p. 1-84. geomorfológiája, In Bialik: Magyarázó ESZTERHÁS, I. (1988-a). A Tátika a Balaton környéke 1:10.000 bazaltbarlangjai (Basalt Caves in Mount építésföldtani térképsorozatához – Tátika) – Folia musei historico-naturalis Tihany. (Geomorphology of the Tihanyi Bakonyiensis (7. sz.) Zirc, p. 13-22. Peninsula, In Bialik: Explanatory Note ESZTERHÁS I. (1988-b): A Kovácsi-hegy for the Engineering Geological Map bazaltbarlangjai (Basalt Caves in Mount of Lake Balaton Region – Tihany, 1 : Kovácsi) Folia musei historico-naturalis 10 000) Hungarian Geological Survey Bakonyiensis (7. sz), Zirc, p. 23-36. Publication, Bp. 1970. p. 47-55. ESZTERHÁS, I. (1988-c). A magyarországi CHOLNOKY, J. (1931). Tihany, morfológiai bazaltbarlangok kutatottságának ered- megfigyelések (Morphologicalményei (Results of Basalt Cave Research Observations In Tihany Peninsula) - in Hungary) – Karszt és Barlang (1988 I. Matematikai és Természettudományi füzet), Budapest p. 15-20. 36 Eszterhás and Szentes CAD. LAB. XEOL. LAXE 37 (2013)

ESZTERHÁS, I. (1984-a). A Pokol-lik (The Hungary, Part I-II., XIV. Syposium on Pokol Hole) – Lychnis, a Vulkánszpele- Vulcanspeleology, Queensland, Australia ológiai Kollektíva kiadványa, p. 2010, Proceedings, p. 179-196. 28-35. GYALOG, L. (2005). Magyarázó ESZTERHÁS, I. (1984-b). Magyarország Magyarország fedett földtani térképéhez, jégbarlangjai (Ice Caves in Hungary) 1:100 000 (Az egységek rövid leírása), – Lychnis, a Vulkánszpeleológiai (Explanation Note for Geological Kollektíva kiadványa, Kapolcs p. 36-42. Map of Hungary, 1 : 100 000, Short ESZTERHÁS, I. (1993). Genotypes of descriptions of the units) Budapest, caves in volcanic rocks in Hungary – Hungarian Geological Survey. Conference on the karst and research JUHÁSZ, Á. (1987). Évmilliók emlékei – activities of educational and research (Relics from Millions of Years) Gondolat institutions in Hungary, Jósvafő p. 81-86. Kiadó, Budapest p. 1-562. ESZTERHÁS I. and SZENTES, G. OZORAY, G. (1960). The genesis of non-karstic (2004). Magyarország nemkarsztos natural cavities as elucidated by Hungarian barlangjainak katasztere – (A List examples –Karszt- és Barlangkutatás (II. of Non-karstic Caves in Hungary) kötet), Budapest p.127-136. http//:geogr.elte.hu/nonkarstic MEDNYÁNSZKY, M. (2009). Magyaror- ESZTERHÁS, I. and SZENTES, G. (2009). szági barlanglakások (Cave-dwellings in Overview of the Non-karstic Caves in Hungary) – TERC Kereskedelmi és Szol- Hungary, 15th International Congress of gáltató Kft. Budapest p. 89-91, 177- 182. Speleology, Kerrwille, Texas, USA 2009, SZENTES, G. (1971). Caves formed in the Proceedings, Vol. 3, p.1474 - 1480 volcanic rocks of Hungary – Karszt- és ESZTERHÁS, I. and SZENTES, G. (2010). Barlangkutatás (VI. kötet), Budapest p. Caves formed in Volcanic Rock in 117-129.