Optymistychna Cave
{{Short description|Gypsum cave system in Korolivka, Ukraine}}
{{Use dmy dates|date=January 2025}}
{{Infobox cave
| name = Optymistychna
| photo = Optymistychna Cave.jpeg
| location = near Ukrainian village of Korolivka, Chortkiv Raion, Ternopil Oblast
| coords = {{Coord|48|44|33|N|25|59|37|E|display=inline,title}}
| discovery = 1966
| geology = gypsum
| website = {{URL|http://optymistychna.com/en/}}
}}
The Optymistychna ({{langx|uk|Оптимістична|lit=optimistic}}, also known as Peshchera Optimistitscheskaya){{cite book|title=The Jewel Cave Adventure: Fifty Miles of Discovery under South Dakota|url=https://archive.org/details/jewelcaveadventu00conn|url-access=registration|author=Herb, Jan Conn|author-link=Jan and Herb Conn|date=1977|isbn=0-914264-20-6|page=[https://archive.org/details/jewelcaveadventu00conn/page/230 230]}}{{Efn|This English transliteration was used during the Soviet era but is now deprecated.|name=|group=}} is a gypsum cave located near the Ukrainian village of Korolivka, Chortkiv Raion, Ternopil Oblast.{{Cite web|url=http://www.cave-ua.narod.ru/engl/hist_op.htm|title=Optimistic cave. Speleotourism. Active and extreme tourism. Travel.|website=www.cave-ua.narod.ru|access-date=2017-06-28}} Approximately {{Cvt|264|km|}}{{cite web |last1=Guden |first1=Bob |title=World's Longest Caves |url=http://www.caverbob.com/wlong.htm |archive-url=https://web.archive.org/web/20060515145704/http://www.caverbob.com/wlong.htm |url-status=usurped |archive-date=May 15, 2006 |website=Caver Bob |accessdate=5 November 2020}} of passageways have been mapped within.{{Cite book|url=https://books.google.com/books?id=alDky3N0CmkC&q=Optymistychna&pg=PA830|title=Encyclopedia of Caves|last1=White|first1=William Blaine|last2=Culver|first2=David C.|date=2012|publisher=Academic Press|isbn=9780123838322|pages=830|language=en}} As a result, it is the longest cave in Europe and the seventh-longest cave in the world,{{Cite web|url=http://ukrainegoodnews.com/optymistychna_is_the_longest_cave_in_ukraine.html|title=OPTYMISTYCHNA IS THE LONGEST CAVE IN UKRAINE - Information Portal Good News|website=ukrainegoodnews.com|access-date=2017-06-28}} after Mammoth Cave, Sistema Sac Actun, Jewel Cave, Shuanghedong and Sistema Ox Bel Ha. It is also the longest gypsum cave in the world.{{cite web |last1=Guden |first1=Bob |title=World's Longest Caves |url=http://www.caverbob.com/wlong.htm |archive-url=https://web.archive.org/web/20060515145704/http://www.caverbob.com/wlong.htm |url-status=usurped |archive-date=May 15, 2006 |website=Caver Bob |accessdate=5 November 2020}}
History
The cave complex was discovered by members of the Lviv speleological club "Cyclope" in 1966. It was entirely unknown before then.{{Cite book|title=Natural Wonders of the World|url=https://archive.org/details/naturalwondersof00sche|url-access=registration|publisher=Reader's Digest Association, Inc|year=1980|isbn=0-89577-087-3|editor-last=Scheffel|editor-first=Richard L.|location=United States of America|pages=[https://archive.org/details/naturalwondersof00sche/page/282 282]|editor-last2=Wernet|editor-first2=Susan J.}} There have been more than 50 expeditions since its discovery, 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 {{Cvt|130.4|km|}}, but the two caves have not yet been found to be connected.
In 2008, the cave was recognized as a Natural Wonder of Ukraine.[http://7chudes.in.ua/info/364.htm Optimistic Caves] {{webarchive|url=https://web.archive.org/web/20090324200537/http://7chudes.in.ua/info/364.htm|date=2009-03-24}}
Geology
File:Optymistychna Cave RB.jpg
The entire cave lies under a 2 km square area in a layer of Neogene period gypsum that is less than {{Convert|30|m}} thick.{{Cite book|url=https://books.google.com/books?id=8e80DAAAQBAJ&q=Optymistychna+cave&pg=PA676|title=Evaporites: A Geological Compendium|last=Warren|first=John K.|date=2016-05-18|publisher=Springer|isbn=9783319135120|pages=677|language=en}} The passages tend to be fairly small, no more than {{Convert|3|m|4=0}} wide and {{Convert|5|ft|order=flip}} tall for most, although at intersections they can be up to {{Convert|10|m}} 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 speleothems. 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.
Notes
{{notelist}}
See also
References
{{Reflist}}
External links
{{Commons category}}
- {{Official website|http://optymistychna.com/en/}}
- [https://web.archive.org/web/20110722053819/http://www.ijs.speleo.it/pdf/6.64.25_Klimchouk_Ukraine.pdf Chapter II.9, Gypsum Karst in the Western Ukraine by Alexander Klimchouk] article appearing in: International Journal of Speleology, vol. 25, #3-4, 1996, p. 263-278.
{{Seven Natural Wonders of Ukraine}}
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