Optymistychna ( uk, Оптимістична: meaning "optimistic", also known as Peschtschera Optimistitscheskaya) is a
gypsum
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. ...
cave
A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...
located near the
Ukrainia
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian invas ...
n village of
Korolivka,
Chortkiv Raion,
Ternopil Oblast
Ternopil Oblast ( uk, Тернопі́льська о́бласть, translit=Ternopilska oblast; also referred to as Ternopilshchyna, uk, Терно́пільщина, label=none, or Ternopillia, uk, Тернопілля, label=none) is an obl ...
.
Approximately of passageways have been mapped within.
As a result, it is the
longest cave
This list of longest caves includes caves in which the combined length of documented passageways exceeds . In some of these caves, passageways are still being discovered.
Geographical distribution
Caves are found around the world. The largest ...
in
Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...
and the fifth-longest cave in the world, after
Mammoth Cave
Mammoth Cave National Park is an American national park in west-central Kentucky, encompassing portions of Mammoth Cave, the longest cave system known in the world.
Since the 1972 unification of Mammoth Cave with the even-longer system under F ...
,
Sistema Sac Actun
Sistema Sac Actun (from Spanish and Yucatec Maya meaning "White Cave System") is an underwater cave system situated along the Caribbean coast of the Yucatán Peninsula with passages to the north and west of the city of Tulum. Discovery of a connec ...
,
Jewel Cave
Jewel Cave National Monument contains Jewel Cave, currently the third longest cave in the world, with of mapped passageways. It is located approximately west of the town of Custer in Black Hills of South Dakota. It became a national monument ...
and
Sistema Ox Bel Ha
Sistema Ox Bel Ha (from Mayan meaning "Three Paths of Water"; short Ox Bel Ha) is a cave system in Quintana Roo, Mexico. It is the 2nd longest explored underwater cave in the world and ranks fourth including dry caves. As of January 2022 the surv ...
. It is also the longest
gypsum
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. ...
cave in the world.
History
The
cave complex
A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...
was discovered by the
speleologist
Speleology is the scientific study of caves and other karst features, as well as their make-up, structure, physical properties, history, life forms, and the processes by which they form (speleogenesis) and change over time (speleomorphology). ...
s of the Lviv
speleological
Speleology is the scientific study of caves and other karst features, as well as their make-up, structure, physical properties, history, life forms, and the processes by which they form (speleogenesis) and change over time (speleomorphology). ...
club "Cyclope" in 1966. It was entirely unknown before then.
There have been more than 50 expeditions since then, but exploration has slowed significantly in recent years, and very little surveying is currently being done.
The cave is located very close to the
Priest's Grotto or Ozerna Cave, the eleventh-longest cave in the world at , but the two caves have not yet been found to be connected.
In 2008, the cave was recognized as a
Natural Wonder of Ukraine.
Geology
![Optymistychna Cave RB](https://upload.wikimedia.org/wikipedia/commons/b/b8/Optymistychna_Cave_RB.jpg)
The entire cave lies under a 2 km square area in a layer of
Neogene period
The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...
gypsum that is less than thick.
The passages tend to be fairly small, no more than wide and tall for most, although at intersections they can be up to tall.
They are often choked with mud. They comprise a dense network on several levels, making Optymistychna known as a "maze cave".
Optymistychna's gypsum bed is topped with a limestone layer, which has seeped through into the cave via erosion and formed into
calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...
speleothem
A speleothem (; ) is a geological formation by mineral deposits that accumulate over time in natural caves. Speleothems most commonly form in calcareous caves due to carbonate dissolution reactions. They can take a variety of forms, depending on ...
s.
At other places, the gypsum has formed crystals, often tinted a multitude of colors by
mineral salt
Halite (), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pi ...
s. In some areas, large
gypsum rosettes have formed, colored black by
Manganese oxide Manganese oxide is any of a variety of manganese oxides and hydroxides.Wells A.F. (1984) ''Structural inorganic chemistry'' 5th edition Oxford Science Publications, . These include
* Manganese(II) oxide, MnO
* Manganese(II,III) oxide, Mn3O4
* Mang ...
.
Notes
See also
*
List of longest caves
This list of longest caves includes caves in which the combined length of documented passageways exceeds . In some of these caves, passageways are still being discovered.
Geographical distribution
Caves are found around the world. The largest ...
References
External links
Official site of Optimistic caveChapter II.9, Gypsum Karst in the Western Ukraine by Alexander Klimchoukarticle appearing in: International Journal of Speleology, vol. 25, #3-4, 1996, p. 263-278.
{{DEFAULTSORT:Optymistychna
Geography of Ternopil Oblast
Gypsum caves
Caves of Ukraine
Natural heritage sites in Ternopil Oblast