Optymistychna
Locationnear Ukrainian village of Korolivka, Chortkiv Raion, Ternopil Oblast
Coordinates48°44′33″N 25°59′37″E / 48.74250°N 25.99361°E / 48.74250; 25.99361
Length230 km (140 mi)[1]
Discovery1966
Geologygypsum

Optymistychna (Ukrainian: Оптимістична: meaning "optimistic", also known as Peschtschera Optimistitscheskaya)[2][lower-alpha 1] is a gypsum cave located near the Ukrainian village of Korolivka, Chortkiv Raion, Ternopil Oblast.[3] Approximately 264 km (164 mi)[4] of passageways have been mapped within.[1] As a result, it is the longest cave in Eurasia and the sixth-longest cave in the world,[5] after Mammoth Cave, Sistema Sac Actun, Jewel Cave, Shuanghedong and Sistema Ox Bel Ha. It is also the longest gypsum cave in the world.[1][6]

History

The cave complex was discovered by the speleologists of the Lviv speleological club "Cyclope" in 1966. It was entirely unknown before then.[7] 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.[3] The cave is located very close to the Priest's Grotto or Ozerna Cave, the eleventh-longest cave in the world at 130.4 km (81.0 mi), but the two caves have not yet been found to be connected.[1]

In 2008, the cave was recognized as a Natural Wonder of Ukraine.[8]

Geology

Speleothems inside Optymistychna Cave.

The entire cave lies under a 2 km square area in a layer of Neogene period gypsum that is less than 30 metres (98 ft) thick.[7][9] The passages tend to be fairly small, no more than 3 metres (10 ft) wide and 1.5 metres (5 ft) tall for most, although at intersections they can be up to 10 metres (33 ft) tall.[7] 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 speleothems.[7] At other places, the gypsum has formed crystals, often tinted a multitude of colors by mineral salts. In some areas, large gypsum rosettes have formed, colored black by manganese oxide.[7]

Notes

  1. ↑ This English transliteration was used during the Soviet era but is now deprecated.

See also

References

  1. 1 2 3 4 White, William Blaine; Culver, David C. (2012). Encyclopedia of Caves. Academic Press. p. 830. ISBN 9780123838322.
  2. ↑ Herb, Jan Conn (1977). The Jewel Cave Adventure: Fifty Miles of Discovery under South Dakota. p. 230. ISBN 0-914264-20-6.
  3. 1 2 "Optimistic cave. Speleotourism. Active and extreme tourism. Travel". www.cave-ua.narod.ru. Retrieved 2017-06-28.
  4. ↑ Guden, Bob. "World's Longest Caves". Caver Bob. Retrieved 5 November 2020.
  5. ↑ "OPTYMISTYCHNA IS THE LONGEST CAVE IN UKRAINE - Information Portal Good News". ukrainegoodnews.com. Retrieved 2017-06-28.
  6. ↑ Guden, Bob. "World's Longest Caves". Caver Bob. Retrieved 5 November 2020.
  7. 1 2 3 4 5 Scheffel, Richard L.; Wernet, Susan J., eds. (1980). Natural Wonders of the World. United States of America: Reader's Digest Association, Inc. pp. 282. ISBN 0-89577-087-3.
  8. ↑ Optimistic Caves Archived 2009-03-24 at the Wayback Machine
  9. ↑ Warren, John K. (2016-05-18). Evaporites: A Geological Compendium. Springer. p. 677. ISBN 9783319135120.
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