Outline of Romanian Karst

Outline of Romanian Karst

About 2% of the land surface of Romania consists of karst. This low percentage is due to Pliocene and Quaternary deposits which overlie the old formations, including the karst forming rocks, in broad regions. More than 12,000 caves are known, most of these being well decorated with speleothems having a great aesthetic value. The most important karst regions of Romania lie in Apuseni Mountains (western part of the country) and in southern Carpathians (Aninei Mountains and Mehedinti Plateau). Karst features are to be found as well, in many other regions of the country (Rodnei, Bucegi, Piatra Craiului, Retezat Mountains and Dobrogea).

The longest underground system (Wind Cave, over 45 km) is located in the northern part of Padurea Craiului Mountains. The cave is developed in four distinct levels; the lower one carry an active stream. The attractions of this cave consist in its various kinds of gypsum speleothems and in so-called "Racovita Meanders". The cave is closed and can be visited just in the presence of a guide provided by the Speleological Club CSA Cluj-Napoca, via Cluj Speleological Institute.

The second long cave of Romania is Humpleu cave with over 35 km of galleries and a total denivelation of about 315 m. It has a 5 km long underground stream with more than 30 sumps. The main characteristics of the cave are the wide dimensions of the cavern, the volume of its rooms (up to 2,000,000 cubic meters in The Giants Room - 537/111/35 m -), as well as the richness and the variety of the speleothems (almost all types of calcitic and aragonitic speleothems). Remarkably are the scalenohedric megacrystals of calcite reaching 30-80 cm in length and over 30-50 kg weight. The cave lodges traces of the cave bear.

The deepest cave in Romania (-560 m) is Avenul din Grind (Grind Shaft), located in Piatra Craiului Mountains.

Romania has five glacier caves. The most interesting and visited is "Ghetarul de la Scarisoara" (Apuseni Mountains). It has a 75,000 mc ice block being the third largest glacier cave in the world. Samples of pollen that were extracted from the lowest ice layer gave an age of 3,500 years.

Karst developed on evaporite

Salt and gypsum (less widespread) occur frequently in Miocene formations. These massifs sometimes outcrop, but mostly are overlain by non-karst-forming rocks. Typical dissolution forms (i.e. lapies, dolines, natural bridges or even blind valleys) develop when salt outcrops. The second long cave in salt in the world (over 3.5 km) is located in Subcarpatii Vrancei. Where the salt is in the basement rocks, collapse sinks or suffusion phenomena maybe produced at the surface by underground solution, thus provoking dolines or karstic collapse sinks and valleys. This category also comprises forms resulting from the activity of man, e.g., collapsed salt mines with sinkhole ponds and potholes. Lapies, dolines and small sized caves are to be found on gypsum and anhydrite. Owing to the rapidity of the dissolution, these forms display only an ephemeral existence.

Volcanic rock karst

In the volcanic formations of the east Carpathians, a few known caves are regarded as karst features. As a matter of fact some are lava caverns with opal, while the other ones are formed by the underground erosion of tuffs among the layers of cemented agglomerates. Few lapies and dolines formed on andesites, by dissolution of feldspars.

Thermo-mineral karst

This karst represents a particular case, exhibiting a different genetical process involving only karstic circulation, as observed in the Baile Herculane Springs, and in the Mangalia and Geoagiu areas. The natural and artificial salt lakes in karstic depressions seem no less important.

Speleothems and their mineralogy

Over 50 minerals were identified in various cave environments, many of them being cited for the first time from Romanian caves (i.e. ardealite, anhydrite, bassanite, jarosite, vaterite). Among these, Crisite is a new amorphous mineral species described for the first time from Bolhac Cave (Padurea Craiului Mountains). It appears along the underground stream bed, covering both sandy alluvia and its limestone borders. The analysis to which the white-yellowish mineral has been subjected, allowed to assign it to the group of hydrated aluminum sulphate-silicates.

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The picturesque scenery, the wild forest covering several karst zones, gorges and particularly the caves are first class attractions. We welcome you to come and visit our karst and caves.

The present text is a compilation of informations published in different articles by: Marcian BLEAHU, Pompei COCEAN, Ica GIURGIU, Bogdan-Petroniu ONAC, Vasile SENCU.