Cave exploration. Small and large caves of the world, types of caves and what they are interesting for

Caves are the last unexplored frontier of our planet, mysterious world, which only the most desperate daredevils dare to look into. Labyrinths stretch for miles under our feet underground caves and tunnels. Today the caves remain the most little explored places on the planet, and yet people rarely manage to descend into the dark dungeons first. The strangest and least known animals on Earth already live here...

Postojna Yama, Slovenia
Caves can be divided according to their origin into five groups. These are tectonic caves, erosion caves, ice caves, volcanic caves, and, finally, the most large group, karst caves. Caves, in the entrance part, with suitable morphology (horizontal spacious entrance) and location (close to water) were used by ancient people as comfortable dwellings.

Most of these caves. It is karst caves that have the greatest length and depth. Caves are formed due to the dissolution of rocks by water. Therefore, karst caves are found only where soluble rocks occur: limestone, marble, dolomite, chalk, as well as gypsum and salt.
Limestone, and even more so marble, dissolves very poorly with pure distilled water. The solubility increases several times if dissolved water is present in the water. carbon dioxide(and it is always dissolved in water, in nature), however, limestone still dissolves slightly, compared to, say, gypsum or, moreover, salt. But it turns out that this has a positive effect on the formation of extended caves, since gypsum and salt caves not only quickly form, but also quickly collapse.


Leak formations in Katerloch Cave, Austria.

Such caves can arise in any rocks as a result of the formation of tectonic faults. As a rule, such caves are found in the sides of river valleys deeply cut into the plateau, when huge rock masses break off from the sides, forming sagging cracks (sherlops). Seizure cracks usually wedge together with depth. Most often they are covered with loose deposits from the surface of the massif, but sometimes they form rather deep vertical caves, up to 100 m deep. Sherlops are widespread in Eastern Siberia. They are relatively poorly studied, and probably occur quite often.

Caves formed in insoluble rocks due to mechanical erosion, that is, worked out by water containing grains of solid material. Often such caves are formed on the seashore under the action of the surf, but they are small. However, the formation of caves, worked out along the primary tectonic cracks by streams going underground, is also possible. Quite large (hundreds of meters long) erosional caves are known, formed in sandstones and even granites.

Lava cave, Hawaii.

These caves are formed during volcanic eruptions. The lava flow, cooling down, is covered with a solid crust, forming a lava tube, inside of which molten rock is still flowing. After the eruption has already, in fact, ended, the lava flows out of the tube from the lower end, and a cavity remains inside the tube. It is clear that lava caves lie on the very surface, and often the roof collapses. However, as it turned out, lava caves can reach very large sizes, up to 65.6 km long and 1100 m deep (Kazumura Cave, Hawaiian Islands).

A typical gallery in Mammoth Cave, Kentucky.


It's funny, but mammoths have never been found in the cave. Just English word mammoth also means "huge". Back in the 19th century, this cave was discovered in Kentucky under the Flint Ridge. At first, saltpeter was mined in it, but one day the deposits were depleted and a certain entrepreneur bought that place. With the help of servants, he tried to explore the depths of the dungeon, but failed. By the beginning of the 20th century, as many as 5 tiers and more than 200 grottoes, galleries and passages were discovered in the cave. Their total length was as much as 500 kilometers! End of this underground country so still not found. But the Mammoth Cave cannot boast of special beauties or miracles. Its arches consist of red limestone, which practically does not form streaks, so there are fewer figured stalactites than in other caves, much more modest in size. Although the visual range is poor, the places are called loudly - one of the corridors is called Broadway, and the underground river is called Styx. However, there is something that guides are happy to demonstrate to guests - stone sculpture, reminiscent of the profile of the mother of President George Washington. So that tourists do not leave their autographs on the walls, they are given a special Hall of Records. Respectable guests can leave not a wall inscription, but a respectable business card. From largest city Kentucky, Louisville can be reached by car in 4-5 hours, and the closest city in the cave is the city of Brownsville

241,595 m - length -192.6 m - depth

232,000m-length -15.0 m-depth All speleologists in the world know the Optimistic Cave, and it is not surprising - in terms of the length of the labyrinth, this is the largest cave on the continent and the second largest in the world after the American system Flint-Rich and Mammoth.


218 450m-length -193.9m-depth (Wind Cave), cave in the north in the north-east. foothills rocky mountains(Black Hills Mountains), South. Dakota (USA). Entrance at the bottom of Wind Cave Canyon. Known since 1881. The natural entrance has a diameter of 0.35 m; a shaft with an elevator was built for sightseers. A voluminous labyrinth with a dense network of galleries. The length is over 120 km, the elevation difference is 172 m. The cave is worked out in limestone thermal waters rich in minerals. Equipped for excursions.

209 600m-length -488.9m-depth Lechuguilla (eng. Lechuguilla) - a cave in the national park carlsbad caves. One of the longest caves in the world (210 km) and the deepest cave in the continental United States (−489 m). The cave is unique in its origin and variety of crystalline mineral deposits. The name of the cave corresponds to the name of the canyon in which the entrance is located, and that, in turn, is named after the Latin name of the common local view agaves (Agave lechuguilla).

183 600 m-length -108.5 m-depth (Fisher Ridge), labyrinth-type karst cave in the ridge. Fisher in zap. foothills of the Appalachians, Kentucky (USA). Has three entrances. The length is more than 113 km, the height difference is 60 m. Numerous int. wells connect a multi-level complex of galleries. The river is drained. Green River. Known since 1981. The edge passages are located only 250 m to the east of the Mammoth Cave. Visited by natives 800-1200 years ago.
Ox Bel Ha,Mexico
182 150 m-length -33.5 m-depth Bull Bel Ha (Mayan meaning "three ways of water"; officially System Ox Bel Ha) is a cave system in Quintana Roo, Mexico. It is the longest explored underwater cave in the world.

175 664 m-length -355.1 m-depth

- a cave in the Western Caucasus, which is the second deepest cave in the world (-1753 mi, considered the most difficult in the territory of the former USSR and the most difficult siphon-free cave in the world. It is located in one of the spurs of the Bzybsky ridge in the thickness of reef Jurassic limestones.

Three large underground waterfalls: Irkutsk (the height of the two knees of the waterfall is 45 m), Record (25 m) and Olympic (32 m). A giant blocky collapse in the bottom part is the blockage of the Metrostroy, 127 m high. Most of The route to the bottom part runs along an underground river (the length is more than 7 km, the water flow in low water is from 50 l/s in the upper reaches, up to 200 l/s in the bottom part). The Diamond Gallery is a side passage of the cave at a depth of 750 m, covered with large gypsum crystals for 100 m. Flower way - a passage in a blocky blockage, covered with white crystals

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New Athos cave is a formation in karst rocks in Abkhazia, it is included in the list giant caves in the world.
The ancient abyss on the side of the mountain is called the abyss by many, it was studied in 1961. mini-expedition (4 people). Soon the New Athos cave gained fame, and tourists began to head towards it.

The New Athos cave consists of 9 large cavities, where tourists come. They are attracted by interesting formations inside, similar to skulls, figures, etc. The New Athos cave is interesting, as we have already said, for its size, as well as the legends associated with it, for example, that angels once lived in it.

Big Oreshnaya Cave is largest cave Russia by the length of passages and the volume of underground spaces. This is the largest conglomerate cave on the planet. The conglomerates consist of boulders and pebbles of variously colored limestones and dolomites cemented with reddish-brown calcareous sandstone. They are of variable strength and porosity, subject to dissolution and collapse, to the point of becoming a sticky, reddish brown, sandy clay.

- a cave in the Urupsky district of the Karachay-Cherkess Republic. The most deep cave in the territory Russian Federation. Depth - about 900 m. Length - about 3000 m. (The cave has not been fully explored, so these figures can be increased).
The entrance to the cave is located in the upper reaches of the river. Atsgara, which is the first right tributary of the river. Urup is a hole in the ledge of a ruined limestone rock ledge. The absolute height mark of the entrance is 2825 m above sea level.
Discovered and first examined in August 1994 by a group of speleologists from Rostov-on-Don, Cherkessk and Donetsk

Genetically, the cave can be attributed to the class of corrosion-erosion caves. Morphologically, it is a series of wells (the most significant is the Grand Prix, 65 m deep), alternating with small sub-horizontal passages. Starting from a depth of -630 m (from the Magnitny Hall), the path through the cave runs through the blockage with a vertical amplitude of about 200 m. ).

Ordinskaya cave - located on the eastern outskirts of the village of Orda Perm Territory, on the left bank of the river. Kungur. It is embedded in gypsum and anhydrite of Permian age. Consists of "dry" and underwater parts. The length of the dry part is 300 meters, underwater - 4600 meters. To date Orda cave is the longest flooded cave in Russia. In addition, part of the cave is the longest siphon in the CIS - 935 meters.

The Orda Cave is located in the bowels of Kazakovskaya Gora, a hill with a plateau-like flat top, skirted by the Kungur River. The height of the hill does not exceed 50 m. On its surface there are large sinkholes, in one of which, located on the southern steep slope, is the entrance to the cave

Dolganskaya Yama and Dolphin caves are wintering grounds for bats. Here is the most numerous [source not specified 83 days] colony of wintering bats in Siberia (more than 2000 individuals).
Dolganskaya karst system- the only known complex of voids in Russia in permafrost with a year-round positive temperature. It is a testing ground for geological, biological, paleontological, hydrogeological, glaciological, microclimatic and geomorphological observations. Studied since late 1970s

Rock paintings in Lascaux cave, France.
Primitive people used caves all over the world as a dwelling. Even more often, animals settled in the caves. Many animals died in the cave-traps, starting from steep wells. The extremely slow evolution of caves, their constant climate, and protection from the outside world have preserved a huge number of archaeological finds to us. These are pollen of fossil plants, bones of long-extinct animals (cave bear, cave hyena, mammoth, woolly rhinoceros), cave drawings ancient people (caves Kapova in the Southern Urals, Divya in the Northern Urals, Tuzuksu in the Kuznetsk Alatau), tools of their labor (villages Strashnaya, Okladnikova, Kaminnaya on Altai-human remains of different cultures, including Neanderthals, up to 50-200 thousand years old ( cave Teshik-Tash in Uzbekistan, Denisova cave in Altai, Cro-Magnon in France and many others).
Water, as a rule, is found in many caves, and karst caves owe their origin to it. In the caves you can find drops, streams and rivers, lakes and waterfalls. Siphons in caves often complicate movement, require special equipment and special training. Often there are underwater caves. Air in the caves
In most caves, the air is breathable due to natural air circulation, although there are caves in which you can only be in gas masks. For example, guano deposits can spoil the air. cave deposits
There are mechanical (clay, sand, pebbles, boulders) and chemogenic deposits (stalactites, stalagmites, etc.).
Some caves are equipped for visiting tour groups(the so-called showcavesFor this, in the part of the cave, the most spacious and rich sinter formations, walkways, ladders, bridges are laid, electric lighting is created, in some cases, if the entrance part of the cave is a technically difficult area, tunnels are made. On the territory of the former USSR, the most famous caves are Marble in the Crimea, Kungurskaya in the Urals, Novoafonskaya in Abkhazia.

All the beauty opens up if you go down a little below the recession of the water, where a narrow valley of decent depth has formed, from which you can see the holes leading to the Sablinsky caves. Surprising is the fact that all Sablinsky caves are of anthropogenic origin, looking at them, it is impossible to assume this. However, this is true - the Sablinsky caves were created in the process of making glass, they were dug out, because the glass industry needed a lot of sand. This explains the similarity internal device, which, by the way, does not detract from their merits at all.

This cave complex also includes Pigeon Cave and Yale Coba. Once, in 1825, this cave was visited by the famous Russian playwright A.S. Griboyedov, one of the lower corridors of the cave is named after him.

One of the most beautiful and famous caves in the CIS are

Kungur caves, so named because of the city of Kungur, located in Perm region. The Kungur caves are the real dwelling of the Snow Queen - covered with ice and hoarfrost, they leave an indelible impression of themselves.


Kungur caves attract many tourists, who later tell about huge icicles, about feeling like in a real fairy tale, about how, opening their mouths with admiration, they wandered along the passages.


Kungur cave is one of huge caves on Earth and the only cave in the Russian Federation specially designed for tourists. This incredible natural object, surrounded by many legends, is located in the Urals, between Perm and Yekaterinburg. Researchers claim that the Kungur cave is almost 10-12 thousand years old.

Kapova cave is located in old rock in Bashkortostan, where ancient drawings dating back to the Paleolithic have been preserved. The Kapova Cave was first discovered in the middle of the 18th century, but it was examined in detail already in the middle of the 20th century, when huge galleries with cave paintings were found.


The age of this cave with an underground river is more than 2 million years. It was discovered and explored by the leader of the Maori tribe, Tane Tinorau, and the English surveyor Fred Mays in 1887.





Salt caves have been known for a long time, but it was in the UK that the first artificial salt cave.
The gentle sounds of the waves on the shore, the reassuring rustle of sand under your feet, the invigorating freshness of the salty air. Closing your eyes, you can imagine yourself on the beach. Open them and look around - there is a salt cave around you, and you are not sitting on sand, but on salt, salt on the walls, and in the air, and everywhere.

Dolgorukov massif


The caves are a system with a length of 2.5 km and are not deep, only 25 meters. Opened by the founder of speleology Edouard Alfred Martel.


In 1935, classical music concerts began to be organized here, after lighting was installed and an electric imitation of dawn over water was created.

Along with the usual route to Cango, you can also take the so-called "Adventure Tour" through hard-to-reach passages.

There are over 150 limestone caves in Bermuda, but the most famous are the Crystal Caves. They got their name from the crystal clean water flowing under their vaults. The water is so clear that you can even see the bottom of the caves, the depth of which sometimes reaches 17 meters.
It is believed that the caves were formed during ice ages when the sea level was 100-130 meters lower. Rain water seeped through the soil, and the resulting underground stream with high acidity dissolved the limestone. As a result of this process, voids appeared in the caves. The dripping water formed stalactites and stalagmites.
When the water level in the seas rose, these voids were filled sea ​​water, and the formation of caves stopped.

This cave system is located in the Blue Mountains. The natives call them "Binumea" - which means "Dark Places". They believed in the healing properties of the water of the underground river and brought sick people here.


The widest and highest cave "Lukas" is the most visited. The entrance fee to each cave is taken separately, and than harder route- the more expensive.

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The present underworld- this is how you can describe the cave of the Yellow Dragon, which is located in famous nature reserve Zhangjiajie. Lighting is installed everywhere here, which gives this place a simply unreal look. One gets the impression that you are visiting some fairy-tale character.
The cave itself is very large, with several levels, each with its own unique illumination. At the bottom there is a river that you can go down by boat. We are sure you will remember this trip for the rest of your life!

The cave is located in a remote area of ​​the Selma plateau, about 1600 m above sea level, in Oman. It was discovered in 1983 by Don Davidson, a geologist who studied water resources. Davidson died ten years later, leaving Oman for good to go hiking in the Andes. He rented a car and left a note saying where he was going. Nobody ever saw him again.


By the name of the limestone plateau "Kras" (Karst) in Slovenia are called all the karst caves in the world. Included in the UNESCO World Heritage List, the Škocjan Caves are the most enchanting sight on this plateau.


Majestic karst grottoes, 30 waterfalls and a 2.5 km deep underground gorge are part of this cave system. Its total length is 6 km.

Here you can see: fantastic calcite columns and stalagmites in the Cave of the Winds, and underground river 108 km long in the "Pure Water Cave".


IN " Deer Cave", thanks to a hole in the ceiling, a piece of land appeared covered with lush vegetation, illuminated by the sun. This place is called -" Garden of Eden ".

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"Giant ice world"- this is the name of this cave system, which is located 40 km from Salzburg, translated from German. They were first explored in 1879 by scientist Anton Posselt. Since then, the Eisriesenwelt caves have become one of the most popular tourist places, which is visited annually by about 200 thousand people.


Pride national park USA in New Mexico - Carlsbad Caves have long been known in the world of travelers. First of all, they are appreciated for their stunning stalactite sculptures of the most extraordinary form and unique grottoes! What is only the grotto of the Green Lake, in which the water is of a malachite color.

But people who are terribly afraid of bats are unlikely to like these caves, because there are about seventeen species of them here!

This report is available in high definition.

People very rarely explore the vast and unexplored, but not National Geographic photographer Stephen Alvarez, who has been exploring and photographing the largest and deepest caves in the world throughout his career.

Cave exploration by Stephen Alvarez.

A cave is a cavity in the ground that communicates with the surface by one or more inlets. (Photo by Steven Alvarez):

The largest caves are complex systems of passages and halls, often with a total length of up to several tens of kilometers. (Photo by Steven Alvarez):

Caves according to their origin can be divided into 5 groups: tectonic, erosional, ice, volcanic and, finally, the largest group - karst. Let's talk about them in more detail. (Photo by Steven Alvarez):

(Photo by Steven Alvarez):

As already mentioned, the vast majority of caves - karst. It is these caves that have the greatest length and depth. (Photo by Steven Alvarez):

Karst caves are formed due to the dissolution of rocks by water, so they are found only where there are soluble rocks: limestone, marble, chalk, gypsum or salt. (Photo by Steven Alvarez):

Tectonic caves can occur in any rocks as a result of the formation of tectonic faults. They are found in the sides of river valleys deeply cut into the plateau, when huge massifs of rock break off from the sides, forming cracks. (Photo by Steven Alvarez):

These fissures sometimes form quite deep vertical caverns up to 100 meters deep. (Photo by Steven Alvarez):

3rd type of caves - erosion. They are formed in the rocks due to mechanical, that is, "cut" by water containing grains of solid material. Often such caves are formed on the seashore under the action of the surf, but they are small. (Photo by Steven Alvarez):

Spectacular ice caves are formed in the body of glaciers by melt water. (Photo by Steven Alvarez):

Melt water forms passages, sometimes passable for humans. The length of such caves can be several hundred meters, the depth - up to 100 meters or more. (Photo by Steven Alvarez):

Also, ice caves can be formed in the glacier at the exit point of underground thermal springs located under the glacier. Hot water can create voluminous galleries in the ice. Thermal ice caves are found in Iceland, Greenland and reach quite large sizes. (Photo by Steven Alvarez):

The last type is volcanic caves. They occur during volcanic eruptions. The lava flow, cooling down, is covered with a hard crust, forming a lava tube. After the end of the eruption, lava flows out of the tube from the lower end, leaving a cavity inside the tube. (Photo by Steven Alvarez):

Lava caves can be very large, up to 65.6 km long and 1,100 m deep. (Photo by Steven Alvarez):

In addition to lava tubes, there are vertical volcanic caves - the vents of volcanoes. (Photo by Steven Alvarez):

The living world of the caves is not very rich, however, some animals are found here. Firstly, these are bats that use caves as shelter or for wintering. Moreover, bats often fly into remote and hard-to-reach places in caves, navigating well in narrow labyrinth passages. (Photo by Steven Alvarez):

In addition to bats, insects, spiders, shrimps, salamanders and fish live in some caves. All cave species adapt to complete darkness, and many of them lose their organs of vision. (Photo by Steven Alvarez):

As is known from history, primitive people used caves all over the world as a dwelling. Even more often, animals settled in the caves. (Photo by Steven Alvarez):

Usually water is found in many caves, and karst caves owe their origin to it. Often there are beautiful ones. We have already talked about them in detail. (Photo by Steven Alvarez):

(Photo by Steven Alvarez):

In most caves, the air is breathable, although there are caves where you can only be in gas masks. (Photo by Steven Alvarez):

In addition to caves, which by definition have access to the surface, there are closed underground cavities in the earth's crust. The deepest underground cavity with a length of 2,950 meters was discovered by drilling on the coast of Cuba. (Photo by Steven Alvarez):

In, except for the Earth, caves were found on and. (Photo by Steven Alvarez):

(Photo by Steven Alvarez):

(Photo by Steven Alvarez):

(Photo by Steven Alvarez):

One summer I found myself in a cave for the first time, and in the famous cave of Petralona, ​​located in northern Greece. This cave is of great importance in the field of anthropology and paleontology - it is here, according to Greek scientists, that the skeleton of the oldest Neanderthal man in Europe, who lived in Europe more than 700 thousand years ago, was found. And since then, the question of the cradle of humanity, where humanity nevertheless originated, has been controversial, despite numerous studies and collected evidence.

But most of all, this Greek cave struck me with its size and beauty. Here I first saw a cave lake, stalactites, stalagmites and stalagnates. Passing from hall to hall of this cave, I thought how it happens that “icicles” - stalactites - hang from above. Why do they have such bizarre shapes and do not melt? And below, like trees, other “icicles” grow - stalagmites. What do they grow out of if there are stones around? Why don't they fall? Why are they both hard and brittle at the same time, but wet to the touch? What if you grow a stalagmite or stalactite at home and decorate your room? Or such a curiosity can be useful in everyday life?

After returning home, I decided to investigate this issue. And I had to start with studying the “habitat” of these amazing cave formations - from the caves themselves. There was also a lot of interesting and exciting here. I still had the initial idea and information after visiting the Greek cave. Our guide was very interesting and told in detail about the cave in which I was. But how are the caves themselves born? And why exactly in them, and nowhere else, do stalactites and stalagmites appear? What are these stalactites made of?

In the course of my research, in order to solve the tasks set, I had to study scientific articles and the results of speleological research. Speleology is a science that deals with the study of caves. In addition, I decided to conduct an experiment on growing a stalactite at home.

And in order to understand the nature of stalactites and stalagmites, first I needed to learn everything about caves - what are they and how do they form? I found the necessary theoretical information in encyclopedias and on Internet sites.

Caves. Their education.

A cave is a natural cavity in the upper thickness of the earth's crust, which communicates with the earth's surface by one or more outlets passable for a person. The largest caves are complex systems of passages and halls, the total length of which often reaches several tens of kilometers. Caves are an object of speleology study.

Caves have long been associated with the history of human development. Even in the Stone Age, caves saved people from the winter cold. But even after the ancient people stopped using the caves as dwellings, the caves were surrounded by an aura of the unusual and strange. The Greeks believed that the caves were the temples of their gods - Zeus, Pan, Dionysius and Pluto. In ancient Rome, it was believed that nymphs and sorceresses lived in caves. The ancient Persians and other peoples believed that the king of all earthly spirits, Mithras, lives in the caves. Today, the vast and beautiful caves attract tourists.

In nature, there are no two identical caves. Caves form in different ways. However, all the largest caves in the world are formed in a similar way. Some large caves began to be created 60 million years ago. Rains poured, rivers overflowed, and monolithic mountains slowly collapsed, and large voids appeared inside the hills, mountains and rocks (Appendix 1).

The rock in which the caves arise is limestone. This is a soft rock, it can be dissolved by weak acid. The acid that breaks down limestone comes from rainwater. Falling raindrops take carbon dioxide from the air and soil. This carbon dioxide turns water into carbon dioxide.

Therefore, acid rain watered limestone for millions of years. They constantly dripped onto the mountains, and cracks began to appear on them. And the rains continued to pour. The water flowed, widening the cracks. She found new cracks in the monolith. The cracks widened into tunnels. Tunnels crossed, niches appeared. After millions of years, the caves took their shape. And the water made the caves bigger and bigger.

Some caves have holes in the ceiling (Appendix 2). They formed in the place where water once accumulated, which then broke into the cave. In the caves you can find rows of galleries going one above the other. Streams of water flow through some caves, in others - after their formation, the water goes down, and the cave dries up.

Caves are hidden everywhere: in the mountains, just in stony soil, composed of soft rocks. Caves are built not only by water, but also by wind, sea surf, and volcanic lava. Caves remain after the extraction of rock salt. There are also ice caves, only they are short-lived.

Types of caves.

The caves can be divided according to their origin into five groups. These are tectonic, marine, glacial, volcanic and, finally, the largest and most common group, karst caves.

Tectonic caves can occur in any rocks as a result of the formation of tectonic faults. As a rule, such caves are found in the sides of river valleys deeply cut into the plateau, when huge rock masses break off from the sides, forming cracks (sherlops), which in turn usually converge with depth like a wedge. Sometimes they form rather deep vertical caves up to 100 m deep. This type of caves is widespread in Eastern Siberia.

Sea caves arose under the influence of splashing waves on stone cliffs along the coast (Appendix 3). Sea waves containing grains of solid material (pebbles, fine sand) dissolved the cliffs. They were destroyed, undermined from year to year by the surf. Separate caves are located under water. They are usually the result of the activity of groundwater, washing out soft rocks, for example, the same limestone.

Glacial caves are found in many glaciers and are formed inside the glaciers by melt water (Appendix 4). Glacial melt water is absorbed by the glacier along large fissures or at the intersection of fissures. At the same time, passages are formed along which a person can sometimes pass. Such caves have the shape of a well and reach a depth of 100 meters or more. In 1993, a giant glacial well "Izotrog" with a depth of 173 meters was discovered and explored.

A special type of glacial caves are caves formed in a glacier at the point where underground thermal waters come out. Since the water is hot, it is able to make voluminous galleries. Such caves are located not in the glacier itself, but under it, since the ice melts from below. Thermal glacial caves are found in Iceland, Greenland and reach considerable sizes.

Volcanic or lava caves occur during volcanic eruptions (Appendix 5). The lava flow, cooling down, is covered with a solid crust, forming a lava tube, inside of which molten rock is still flowing. After the eruption has already, in fact, ended, the lava flows out of the tube from the lower end, and a cavity remains inside the tube. It is clear that lava caves lie on the very surface, and often the roof collapses.

However, lava caves can reach very large sizes. Such, for example, as the Kazumura Cave in Hawaii - 65.6 km long and 1100 m deep. And the largest volcanic cave in the world Cueva de Loe Verdes is located on one of the Canary Islands.

Karst caves are the majority of such caves (Appendix 6). It is karst caves that have the greatest length and depth.

Caves are formed due to the dissolution of rocks by water. Therefore, karst caves are found only where soluble rocks occur: limestone, marble, chalk, gypsum and salt. Limestone, and even more so marble, dissolves very poorly with pure distilled water. Solubility increases several times if dissolved carbon dioxide is present in water, and in nature it is always dissolved in water. However, all the same, limestone dissolves poorly, compared, say, with gypsum or, moreover, salt. But it turns out that this has a positive effect on the formation of extended caves, since gypsum and salt caves not only quickly form, but also quickly collapse.

Caves are a special world that has no analogues on the surface. There is neither winter nor summer in the caves. The temperature is always the same. In cold caves, it ranges from +2 to +8 degrees, and in warm and hot - from +15 to +28.

It turns out that the air in the caves is sterile. It has a thousand times fewer germs than on the surface. It turns out that radioactive isotopes of carbon penetrate into the caves along with underground waters. They cause the glow of stalactites, ionize the air, kill microbes.

The longest cave in the world - Flint Mammoth - is located in the USA, in the state of Kentucky. The length of all its corridors is more than 550 kilometers. And the deepest cave is located in Abkhazia - the cave of Krubera-Voronya. A person can go down to 2 kilometers into it.

Despite the fact that so much is already known about caves, more discoveries lie ahead of scientists. Each cave has passages, crevices and corridors that cave travelers - speleologists - do not yet know about. They think that they have already studied everything, but suddenly one day they notice a gap behind a stone blockage, and behind it is a corridor, beyond which there are several more meters of cave beauty.

As a result of these studies, it can be concluded that there are several types of caves, but the most common are karst. For the formation of a cave, a sufficient amount of water precipitation and a successful form of relief are necessary, that is, precipitation from a large area must fall into the cave, and the entrance to the cave must be located noticeably higher than the place where groundwater is discharged.

Stalactites, stalagmites and stalagnates

Water is a great power. She grinds stone when she makes her way, she builds galleries, and then she leaves them, undermines rocks, and they sink, collapse, move. This is how the caves themselves are born. However, water is not only a builder, but also an artist, a sculptor!

Caves are in different rocks, and water brings different particles into them, builds from different materials: from calcite, gypsum, rock salt. The dissolution and destruction of sedimentary rocks by water is called karst - the karst process.

The karst process is two-faced: water dissolves rock in one place, transfers it to another, and there it creates beautiful sinter formations from the same rock - stalactites and stalagmites.

Stalactites (from the Greek stalaktós - flowing drop by drop), are drip-drop formations hanging in the form of conical icicles, draperies, curving fringe or hollow tubes from the vaults and upper parts of the walls of karst caves or other underground voids (Appendix 7).

Stalagmites (from the Greek. stálagma - a drop), drip-and-drop formations of columnar, conical and other shapes, rising from the bottom of caves and other underground karst cavities (Appendix 8).

Stalagnates are sag-drop formations in the form of columns that appear in caves when stalactites and stalagmites join (Appendix 9).

How are they formed? A raindrop, seeping through a crack in the rock, dissolves a piece of stone. Thus, each such drop contains particles of limestone or other minerals. By dissolving limestone, water takes away the mineral calcite from it. A drop of solution saturated with calcite through the smallest cracks reaches the ceiling of an already created cave and hangs on it (Appendix 10).

Gradually, very slowly, the drop evaporates, and the piece of calcite or other mineral brought by it with the thinnest film settles on the ceiling. After some time, the next droplet comes to this place and again deposits calcite. Growing, grains of calcite first turn into a thin transparent and empty tube inside. Why empty? Yes, because the drop itself is empty inside.

But then a grain of sand gets into the drop and clogs the tube. Then other drops begin to flow around this tube from all sides, and a stone icicle grows, the same as the ice one - a stalactite.

But the drops come unevenly from one side or the other, and the stalactite is not quite round. And then it rains on the surface, the water becomes dirty, the stalactite darkens. The rain has stopped, the water is clear again, and the next layer of stalactite has become a different color. If you cut it, then the cut will have the same rings as a tree, but not annual ones. It's just that in spring and autumn there is more water, and the stalactite grows faster. The water is darker, and the ring is darker, there is less water, and growth has stopped (Appendix 11).

I even found the chemical formula for the formation of a stalactite. Here it is: CaCO3 + H2O + CO2 Ca2+ + 2 HCO3

But not all calcite settles on the ceiling and gives growth to the stalactite. Under their own weight, some of the drops fall to the floor, and a stalagmite grows from below towards the stalactite. When a stalactite and a stalagmite join and grow together, a calcite column is formed - a stalagnate. And stalactites, and stalagmites, and columns are very large - tens of meters in height and several meters in diameter.

Water drops, falling on them, form streams that flow around the columns from all sides, and then there are streaks in the form of ribs. If the drops flow down the wall of the cave, then no less amazing streaks appear on it in the form of stone waterfalls, flags and other fantastic formations.

Sometimes streaks of completely unexpected forms appear in the caves. Stalactites suddenly begin to grow at random, creating bizarre stone weaves. Surprisingly beautiful stone and gypsum stalactite flowers appear on the floor and on the walls - corallites, crystallictites and helictites (Appendix 12).

Where there is an imbalance in the flow of the solution - for example, it drips from above, but so little that the drops immediately spread like a film - hybrid forms arise, the stalagmite blooms with a bush. In this case, a wide variety of transitional forms, polymineral forms, and much more arise. For example, you can find formations that exactly copy the architecture of wasp nests. And the gypsum web, which is thinner than a human hair, crumbles into dust at the slightest fluctuation of air.

Billions of drops over millions of years have created in the cave a whole forest of stalactites, stalagmites, fantastic interior decoration of columns and openwork stone curtains, flags and waterfalls (Appendix 13).

On the floor of the cave, flowing water also deposits calcite and forms "baths" that vary in shape and color. The smallest particles of salts of various minerals and metals - copper, cobalt, iron - make the stains pink, yellow, blue, red, carrot, black. Very rarely found in the "baths" the so-called cave pearls. It is formed in the same way as the sea, but not in the shell. Sometimes cave pearls reach three to five centimeters in diameter - almost like a ping-pong ball - but this is very rare.

A wide variety of stalactites can be found in karst caves. For example, tubular stalactites, they are pasta. The channel, which runs along their entire length, for centuries automatically suggested to researchers that the stalactite is fed through this channel. But it turned out that this was not the case at all. It turned out that the channel is just a consequence of crystallization along the perimeter of the detached drop. That is why new stalactites, growing in place of the broken ones, do not continue the original pipe, but grow slightly to the side, where it is more convenient for water to drip.

The most spectacular of the stalactites are draperies (Appendix 14) that appear on sloping walls. It is then that the growing stalactite begins to influence the point of separation of the drop, and it becomes mobile, moving along the slightest whim of the water stream and fixing in its dashingly swirling form the direction of these jets, where they should flow.

When a mineral changes, say, calcite to gypsum, the cave also changes, and beyond recognition (Appendix 15). Gypsum has a different crystallization chemistry. Therefore, in such a cave, gypsum formations “grow” - “crystal chandeliers” (Appendix 16) and gypsum “snow-covered firs”.

They form in an extremely remarkable way. The cave also has dry and wet seasons, and gypsum is a highly soluble mineral. When moisture settles on the surface, the gypsum dissolves. When the moisture evaporates, the gypsum crystallizes. Water "likes" to settle in depressions, and to evaporate from ledges is elementary physics. And then it turns out that the inner cavity of the stalagmite continues to dissolve, and the outer surface - to grow, moreover, branched bushes of crystals. Those same “snow-covered firs” appear. When the wall becomes thinner so that the stalagmite no longer holds its own weight, then “dying”, it falls into itself, providing its own “reserves” of gypsum for the growth of other formations.

It takes a lot of time to create all this extraordinary underground beauty. Scientists have calculated that, on average, a stalactite grows by four tenths of a millimeter per year and grows by only four centimeters in a hundred years. And in 100 years, a stone icicle will appear at this place - a stalactite 4 centimeters long. And every 100 years, the stalactite will grow by the same amount. And below, where the drop fell, a stone tower will grow - a stalagmite. After millions of years, the stalactite and stalagmite will unite and turn into a sparkling column. This means that a man who broke a meter-long stone icicle destroyed what nature had been creating for about two and a half thousand years!

Thus, in the course of the study, I learned that stalactites, stalagmites and stalagnates are drip-leak formations in caves. The process of formation of stalactites and stalagmites is a complex chemical process, which consists in the fact that water dissolves the rock, transfers it to another place and after a while deposits it back, creating sinter formations. This process takes hundreds, thousands of years.

Other mysteries of the caves

Paleontology is the science that studies fossil plants and animals. Fossils are the remains of animals that lived millions of years ago, which have survived to this day. It is mainly through the study of fossils that we know what the animal world was like hundreds of millions of years ago.

At the beginning of my work, I already said that the study of caves is of great scientific importance in paleontology, mineralogy, anthropology, and archeology. This is confirmed by the loudest and most interesting discovery of the 20th century - the discovery of the Petralona cave in northern Greece. I myself was in this cave, and it became the starting point for me in studying the mechanism of formation of caves and stalactites. Therefore, I want to briefly talk about it (Appendices 17-24).

In 1959, on the peninsula of Halkidiki, in northern Greece, at an altitude of 250 meters above sea level, at the foot of Mount Katsika, an entrance to a cave was discovered. It all happened quite by accident, a shepherd named Petralona was tending sheep in the area. Once, having heard the quiet murmur of water, I decided to carefully examine the foot of the mountain and stumbled upon the entrance to the cave. Further research was undertaken by specialists, in particular the famous Greek anthropologist Aris Poulianos, who later built a paleontological museum next to the cave and even sometimes conducts excursions himself. I was lucky, I also saw him when I was on a tour.

The area of ​​the cave is 10 thousand square meters, the total length of the corridors (passages) is 1,500 meters. The tourist route, open to the public, is still only 600 meters. The finds that were discovered inside this cave made a real revolution in anthropology. In 1960, a year after the discovery of the cave itself, a skull and skeleton of an ancient European, a Neanderthal man, called archanthropus, was discovered inside. The results of the first study of the skull were presented at the International Congress of Anthropologists in Moscow in 1964 and made a great impression on specialists.

In addition, petrified bones, stone tools, animal remains - bears, hyenas, turtles, rhinos, lions and even a giraffe were found in the cave. And another unusual find from the Petralona cave is traces of fires and ash, which is 1 million years old. According to scientists, these are the oldest traces of the use of fire by man.

Until recently, it was believed that the age of mankind is 3.5-4 million years, and Africa is the homeland. However, the finds from the Petralone cave and their dating give the right to assume that the cradle of mankind is South-Eastern Europe, and man appeared 11-12 million years ago in Greece. All finds from the Petralona cave are exhibited in the anthropological museum built next to the cave.

In fact, there are a lot of mysteries and mysteries in the caves. As I found out in the course of my research, the animal world of the dungeons is unusual and interesting. Even primitive man knew and painted on the walls of animals that lived in caves - a cave lion, a hyena, a cave bear. By the way, rock paintings also carry a lot of interesting information for scientists (Appendix 25).

Ancient animals died out long ago, people left the caves, but the caves themselves were not empty. Serious biological research into the underworld began only in 1831, when the first cave beetle was found. Since then, many different cave creatures have been discovered - both aquatic and terrestrial. These are troglobionts, which means "living in caves" - crustaceans, fish, wood lice, centipedes, spiders, false scorpions and other insects.

The adaptation of living organisms to cave life is very complex and diverse. Compared to their terrestrial relatives, they have longer and thinner bodies, more elongated legs and antennae, they are transparent and colorless. Since there is no light in the caves, they do not need sight, and therefore they do not have eyes. In the caves there are blind beetles, fish, amphibians, crayfish and even blind and wingless flies. The air in the caves is saturated with moisture, and therefore troglobionts can live both in water and on land.

According to scientists, animals and insects went into the caves due to climate change on Earth, namely during a cold snap. Thus, the majority of modern cave dwellers are representatives of past eras, living fossils that are no longer found on the surface, but have retained the appearance and habits of bygone millennia.

However, most lovers of the dark spend only part of their lives underground. For example, butterflies only hibernate in caves. And some species of grasshoppers, leading a nocturnal lifestyle, are there all day. The cave bear also belonged to them, because the cave was for him only a place of rest. The hyena and the lion spent even less time in the caves. Unlike the cave bear, they never went far into the depths of the cave, but stayed at the entrance.

Treasures of the caves - another mystery and mystery of the caves. For many millennia, legends and tales have been talking about treasures hidden in caves. Under the ground, more than once, the bones of lost treasure hunters were found, who never managed to find the treasured treasures. One of the caves in the Czech Tatras is called the Cave of the Treasure Seekers. And how many legends are made about pirate treasures hidden, including in caves. But in every legend there is some truth.

CONCLUSION

The object of my research was the caves and their mysteries, the main of which are stalactites, stalagmites and stalagnates, the mechanism of their formation and the possibility of creating in domestic conditions, that is, at home. At the beginning of the work, I intended to conduct an experiment on such cultivation. I thought that by studying the nature and mechanism of stalactite formation, I could do the same myself. But even in the course of theoretical research, I realized that it is impossible to grow a real stalactite at home.

In order to grow a stalactite, several very essential conditions are required. Namely - a cave with a certain relief and microclimate, a constant flow of water, the presence of carbon dioxide, and most importantly - several hundred and even thousands of years. Human life is not enough to repeat such an unusual and beautiful phenomenon as a stalactite or stalagmite. There is only one thing left - to admire and cherish.

Based on the results of my research, I can draw the main conclusion - there are such natural phenomena that a person should study, protect, but it is not at all necessary to repeat them or use them in their life. Perhaps someday people will invent a time machine or a time accelerator and then they will be able to artificially accelerate the natural process of stalactite growth, but the next question arises, is it necessary?

Why do I need this knowledge? Can they be useful to me in life? I think yes. And mainly, in order to better understand the world around us, to see and appreciate the beauty that nature can create. And yet - suddenly the climate on the Planet will change dramatically again and people will again have to return to the caves. With this knowledge, it will be easier for me to get used to it myself and help others.

A large number of secrets and mysteries are always associated with caves, because this is a whole world of magic, silence and silence. Even in ancient times, caves were used to shelter humans and animals, and some were even considered the abode of the gods. In nature, there are no two identical caves, because some have lakes, others have halls with grottoes, wells, glaciers and waterfalls. For many thousands of years, rainwater has destroyed the stone, forming stalactites and stalagmites of bizarre shape. In some caves, calcite is formed in the form of pearls, flowers, thin twigs, crumbling at the slightest touch. We present to your attention a rating of the most amazing and beautiful caves in the world.

1Giant Crystal Cave, Mexico

A cave of giant crystals in Mexico was discovered by ordinary miners who were working in the south of the country. At the depth of a three-hundred-meter mine, they discovered a cave, literally strewn with huge crystals from the inside. The crystals in the caves are translucent, and their color varies from bright white to golden. The crystals are rectangular or cylindrical in shape, and their length reaches several meters. The base of the cave is stone, which indicates its ancient origin. The huge crystals in it were formed by nature over several million years. Apparently, the room of the Crystal Cave was previously filled with rock, which was gradually washed away by underground waters, after which such unusual formations remained.

2. Na Pali Coast Cave in Kauai, Hawaii

The Hawaiian island of Kauai was formed over 5 million years ago as a result of volcanic activity in the area. One of the most spectacular sights of the island is the coast of Na Pali. Here, the rocks practically hang over the sea, and exotic plants grow on their surface and various birds nest. In addition to picturesque volcanic mountains and evergreen beaches, tourists are attracted here by mysterious caves. For many centuries, sea waves methodically carved volcanic rocks, thus forming the caves of Hawaii. In the caves you can enjoy virgin nature and sea views.

3. Melissani Cave, Greece

The Melissani cave, located on the Greek island of Kefalonia, was forgotten for several centuries and was remembered only in 1951, when the Greek Giannis Petrohelios again found and opened it. Indeed, even in Greek mythology, this cave was mentioned as the dwelling of the nymphs. The reason for such a violent fantasy of the ancient Greeks is quite understandable - the cave with its turquoise lake surrounded by dense forest looks truly fabulous. Melissani Cave has a stone base, on which there are shallow azure waters, at the top there is a huge stone dome with a huge hole through which sunlight enters deep into the cave, creating amazing reflections on its walls. The entrance to the Melissani cave is also very picturesque - it is overgrown with greenery, and the "door" is decorated with natural brownish stone "plaster".

4. Skocjan Caves, Slovenia

One of the most famous karst cave systems on our planet is the Škocjan Caves. On the beautiful Kras Plateau, located in the southwest of Slovenia, these wonderful caves are officially recognized as a nature reserve and a World Heritage Site. Shkocyansky caves owe their appearance to the local river with the name "River" flowing through it, which for centuries "cut down" the caves in karst deposits. However, as a result of water erosion, several arches of the cave collapsed, forming karst failures "Mala Dolina" and "Velika Dolina", separated by a natural bridge. On the territory of Velika Dolina, the River goes underground, appearing on the surface after 34 kilometers already in Italy. In addition, there are many dangerous funnels, dips and small waterfalls on the territory of the Shkocyan Caves. The largest European grotto, the Martel Hall, is also located in the caves.

5. Marble Caves in Chile Chico, Chile

High in the Andes is one of the deepest lakes in the world - Lago General Carrera (Chilean name) or Lago Buenos Aires (Argentinean name), since the lake is located on the border of Chile and Argentina. Not far from the Chilean city of Chile Chico are the famous Marble Caves. Although the walls of the caves are not made of marble at all, but of limestone, but against the background of turquoise water, its vaults, which have white and blue tones of color, look very impressive. Thanks to this natural beauty, thousands of tourists come to see the Marble Caves every year. Small pleasure boats bring tourists here, allowing you to see all the splendor of the shades of the cave, as well as look into the natural windows, as if melted in the walls of the labyrinth of the Marble Caves - boats can no longer drive there. In addition to the amazing Marble Caves, fishing lovers also come to the lake, because its waters are rich in trout and salmon, as well as some other types of fish.

6. Mammoth Cave in Kentucky, USA

Mammoth Cave is located in the US state of Kentucky. This unique karst cave has a unique microclimate. The cave was discovered about 4,000 years ago; the remains of ancient torches are still found in it. The cave was used by local tribes for various purposes. American scientists have discovered the mummy of a man who died in this cave more than 2,000 years ago. After numerous studies, scientists came to the conclusion that a person was engaged in gypsum mining here. A rare species of shrimp, crayfish and blind fish have been found in an underground river. In addition, flocks of bats live in the cave. Since the end of the 19th century, Mammoth Cave has become a tourist attraction, for which electric lighting was installed throughout its entire length. However, if you wish, you can walk through the cave as in ancient times - with a paraffin lamp.

7. Cenotes of the Yucatan Peninsula, Mexico

Cenotes are peculiar formations in caves that appear in the rocks under the influence of water. South of the Mexican resort of Cancun, located on the Yucatan Peninsula, is one of the most beautiful cenotes. According to some reports, in ancient times Yucatan was an underwater reef. After the water left, huge caves remained. The caves and grottoes of the Yucatan are completely underground. There are no land rivers on the peninsula - they all flow underground. Once upon a time, the Mayan peoples considered cenotes sacred and drank water from them during religious ceremonies. Tourists from all over the world come to the Yucatan to swim, dive and admire the underground scenery. And ancient stalactites and stalagmites make the underwater world truly fabulous. Through the cracks of the caves, sunlight penetrates into the cenotes, giving them a special beauty.

8. Blue Caves, Greece, Zakynthos Island

On Zakynthos, one of the largest Greek islands, there are amazing Blue Caves. Among tourists, the island has gained popularity due to its scenic area, including beaches and villages. In the village of Volimes is located the Blue Cave, which can only be reached through the sea, however, as well as to most of the island. If you visit the Blue Cave at sunset or sunrise, you can enjoy the blue color of the sky and ocean reflected in it. For many years of water erosion, the rocks have taken on the appearance of amazing natural arches. Due to the unusual light effects of the Blue Caves, this place is one of the most visited in Greece. In addition to the beautiful caves, Zakynthos has a famous beach, considered one of the best in the world.

9. Fingal's Singing Cave, Scotland

For many centuries on the island of Staffa (the island belongs to the group of the Inner Hebrides) in Scotland, the rains and the sea have formed one of the largest caves in the world - Fingal's Singing Cave. The cave owes its name to the famous Scottish poet James MacPherson. According to legend, the giant Fingal, in order to connect Scotland and Ireland, built a dam, along which a huge giant passed into his dwelling, while Fingal lay down to rest before the fight with him. However, his wife was resourceful and said that it was the baby, the son of Fingal, who was sleeping. The huge giant imagined the size of the father of this "baby" and fled in fear, destroying the dam behind him. According to legend, Staff Island is part of this dam. The second reason for this name of the cave is the Geltian meaning of the phrase "Cave of Melodies". The name was given to the cave due to the fact that during the surf, the cave hall repeatedly repeats the sounds of the sea, as if singing!

10 Skaftafell Ice Cave, Iceland

On the edge of glaciers, amazingly beautiful structures are often formed - ice caves. In Iceland, on the lagoon of the Svinafellsjokull glacier, there is the famous Skaftafell Cave. Over the past centuries, the glacier has compressed so much that it has almost no air bubbles, due to which almost all sunlight is absorbed, except for the blue fraction visible inside the cave with the naked eye. Although such blue ice is possible only when the upper layer of the glacier is washed away, for example, in winter. However, such light is found in floating icebergs and other ice caves. Skaftafell cave has a seven meter entrance on the shore. At the end of the cave narrows to one meter. However, it is not safe to visit ice caves, as they are constantly transforming and can collapse at any moment. Only in winter visiting such caves is relatively safe. As ice caves move with the glacier, crackles can often be heard inside them.

Caves are cavities formed in the upper part of the earth's crust as a result of natural processes. The scientific language describes these mysterious objects so prosaically. However, true connoisseurs of caves will always have living words for them.

So, for example, Alfred Begley, a Swiss cave explorer, spoke about them: “Under the earth's surface in absolute darkness there is such a huge world that we can talk about a new continent.”

Geographic feature. Significance of the caves

The importance of caves for a person is difficult to overestimate. After all, it was the caves that became the first homes for primitive people, so revealing the secrets kept by the caves helps to add the missing puzzles to the picture of human history and evolution.

The great cognitive value of the caves is evidenced by the increased interest in speleology in recent decades, both from researchers and from tourists and adventurers. Around the world, the number of caves prepared for tourist visits is growing.

Of great importance for agriculture are karst cave cavities, since their presence leads to the withdrawal of groundwater to a great depth, the drying up of the upper layers of the soil, which must be taken into account when planning agricultural work. And some caves with a microclimate characterized by extremely low temperatures are used as large "refrigerators" for storing food and various materials.

The caves are of great importance for the extraction and research of various minerals and some iron ores.

Characteristics of the caves

Caves are protected from the outside world, have a constant internal climate, and evolve extremely slowly. These characteristics make them invaluable for archeology: the caves have preserved for us the remains of ancient people, the bones of extinct animals and pollen from plants.

The speleofauna is not particularly diverse, and yet there are animals and plants that settle mainly in caves or only in them. These are bats, perfectly oriented even in the longest and most intricate underground passages, some insects, shrimps and other crustaceans, spiders, fish and salamanders. Cave dwellers adapted to complete darkness are often completely blind and devoid of pigment.

Cave deposits are divided into mechanical and chemogenic. Mechanical deposits are clay, block blockages, sand, pebbles; chemogenic - stalactites and stalagmites that adorn ancient cave galleries.

Types of caves

Exist artificial(man-made) and natural(formed by natural processes) caves. Natural caves are divided by origin (leading process) into the following five types.

Karst. The largest group. They are the most beautiful, deep and extended. The process of their formation is a consequence of the dissolution of various rocks in water (gypsum, limestone, chalk, salt, marble, etc.). It is in karst caves that stalactites, stalagmites, as well as helicates and amazing cave onyx are formed.

Erosive. Similar in their formation process to karst caves, however, erosional caves are formed as a result of mechanical erosion, i.e. washed out with water containing solid grains (sand, stone fragments, etc.). Often formed along the coastline.

Tectonic. Formed at the sites of tectonic faults. Most common in the sides of river valleys, deeply wedged into the plateau.

Volcanic. They are formed as follows: during a volcanic eruption, the lava flow, cooling down, is covered with a crust, forming a lava tube. Inside the pipe, lava continues to flow for some time, which leads to the formation of a cavity. Volcanic caves also include caves formed by the vents of volcanoes.

Glacial. Formed in the body of glaciers. Among glacial caves, there are caves formed by melt water, caves formed in glaciers at the outlet of subglacial and intraglacial waters, as well as caves formed in glaciers at the outlets of subglacial thermal springs.

The biggest caves

(Shondong Cave)

The largest cave in the world is a cave discovered in 2009 Shondong in Central Vietnam (Quang Binh province). More famous, but smaller mammoth cave located in Kentucky, USA. It is a system of karst caves formed in a limestone layer.

In Russia, the longest is Botovskaya, whose length reaches 60 km. In Romania is movile cave- one of the three caves in the world, formed as a result of the impact on the rock of sulfuric acid. The cave is unique in that it is a closed ecosystem, isolated from the Earth's ecosystem.

The deepest cave

(Krubera Cave)

The deepest cave in the world - Krubera cave or crow- located in Abkhazia (Gagra Range). The cave branches into two branches: the depth of one is 2,196 m, the depth of the other is 1,300 m. It was discovered in 1960.

The longest cave

The longest in the world is the one already mentioned above. Mammoth cave system(Kentucky, USA). Its length is 627,644 m. Mammoth Cave lies in the foothills of the western Appalachians and in the explored part has 20 large halls, the same number of deep mines and about 225 underground passages.