Commune: Wieliczka (pow. wielicki, woj. małopolskie)
Framework element or context represented:
Mineralogical phenomena in the salt mine.
Primary geological/geomorphological interest:
Two caves with walls and roofs covered by halite crystals.
Comparative assessment justification:
Unique crystal caves within Miocene salt deposit.
Protection status and accessibility:
First protective regulations in 1928 and 1949; the nature reserve based on the Law of Nature Protection established in 2000. Crystal Caves is most important part of the Wieliczka Salt Mine - World Heritage UNESCO (1978). Buffer zone 3181850 m3 (117.9 m a.s.l. to the surface at 260 m a.s.l.)
Character of site: Caves.
Area: 457600 m3.
Altitude: 146.2 - 190.2 m a.s.l.
Lithology: sandstones, conglomerates, breccias, gypsum (anhydrites), other evaporite rocks, silstones, claystones
Discipline: Mineralogy, Geology of mineral deposits
Process Age: *all periods
Bedrock Age: Quaternary, Neogene, *all periods
Description of primary interest:
Folded saliferous Miocene deposits accessible in Wieliczka Salt Mine are spread in Carpathians trust front near Cracow. Two Crystal Caves occur in the eastern part of mine about 80 m under the surface. They were discovered in 1898-1899. The first detailed description and act protected are dated at 1928. Lower cave is natural void with a lengthened upward shape 706 m3 in volume. Upper part of its walls and the roof are covered with halite crystals. About 7 m above this, the upper cave 1000 m3 in volume is situated. It shape has been disfigured by old mining works and the remaining fragments of crystalline covers are conserved. The edges of crystals attain 26-34 cm but in most cases this size does not exceed 20 cm or 10 cm. Halite specimens originating from Crystal Caves as the model examples of the crystallography and its exceptional transparency are most valuable mineralogical collections of museums in different countries. The geological structure called the Crystal Caves Dome is composed with Badenian salt series of Wieliczka Formation and undersalt beds consist of claystones, siltstones and sandstones with anhydrite and gypsum. Crystal Caves is situated within the Wieliczka Formation, in the contact zone of its salt stratiform part and overlying megabreccia one. Origin of voids is connected with fissures enlarged by processes of salt dissolution. Halite crystals from caves are much younger than salts of Wieliczka deposit. Dating by the uranium-thorium method point out the time of recrystallization on cool periods of mezo and neo-Pleistocene.
Literature:
ALEXANDROWICZ Z. (ed) 2000–Crystal Caves in the Wieliczka Salt Mine (English sum.). Studia Naturae 46: 1-205. ALEXANDROWICZ Z., BRZEŹNIAK E. 1997–Threat of the Crystal caves environment in Wieliczka Salt Mine (English sum.). Folia Geogr. ser. Geogr.-Physica 28: 59-78. KREUTZ S.1928–La Grotte à Cristaux de Wieliczka en tant que première réservation souterraine en Pologne (French sum.). Zabytki Przyr. Nieożywionej Ziem Rzeczypos. Pol. 1: 17-23. MÜLLER A. 1928–Sur la découverte d’une Grotte à Cristeau dans les mines de Wieliczka. Situation de la Grotte (French sum.). Zabytki Przyr. Nieożywionej Ziem Rzeczypos. Pol. 1: 24-29. PAWLIKOWSKI M., WIEWIÓRKA J. 1988–The Crystal Caves in Wieliczka (English sum.). Ochrona Przyrody 46: 383-394.