What is the meaning of the words "karst cave"? How did these beautiful natural objects form? You can find answers to these questions in this article. In addition, here we list the world's longest karst caves (you can also see photos of these underground voids). Curiously, most of them are located in the United States.
A cave is ... The meaning of the words "karst cave"
These underground voids from ancient times served as a dwelling for animals, as well as primitive people. They hid them from the cold and wild predators. Interestingly, caves were discovered not only on Earth, but also on the Moon, Mars. Let us first clarify the meaning of the words “karst cave”.
This phrase consists of two parts: "cave" and "karst".
- A cave is any underground cavity of natural origin.
- Karst is both a process and the result of the destruction (dissolution) of certain rocks by aggressive (in chemical composition) groundwater.
The term "karst" itself comes either from the German word karst, or from the name of the plateau in Slovenia (Kras), where these natural phenomena are especially pronounced.
What is a karst cave?
This type of cave is the most common among all other underground cavities. What is a karst cave and how is it formed?
There are two main definitions. According to the first, this is a natural cavity (void) in the upper part of the earth's crust, which is connected to its surface by one or more entrances. According to the second definition, a karst cave is an underground cavity of natural origin, which is not illuminated by the Sun, but is accessible for penetration from outside.
The caves are studied by a special science - speleology, material for which is often mined by the so-called speleotourists.
How are karst caves formed?
Caves of this type are formed due to exogenous processes, namely, due to the dissolution of rocks by water. It is worth noting that karst caves are present only in those areas of the Earth where unstable rocks occur, which are easily dissolved by water. Among these are gypsum, salt, chalk (kaolin), dolomite, marble and limestone.
Worst of all others, limestone and marble are destroyed. Caves in these rocks form a very long time. On the other hand, they are better preserved than others. For example, gypsum caves very often collapse and collapse.
An important role in the formation of underground voids is played not only by the chemical composition of water (it must have an increased concentration of carbon dioxide), but also by the presence of cracks and extended faults in the earth's interior. They, as a rule, are those axial lines along which caves form.
Most of the caves studied are relict type systems. This means that the water has already left these underground cavities. Nevertheless, it is she who acts as the sculptor who forms the internal "microrelief" of the cave. Underground water, saturated with sulfates and carbonates, lays them on the walls, floor and arches of underground cavities. That is what forms what we call stalactites and stalagmites. Very often, these growths take on strange and bizarre shapes that look even more unusual in the darkness.
The main types of caves
According to the mechanism of genesis (formation), apart from karst, tectonic, volcanic, erosion, and also glacial caves are distinguished.
Underground cavities are also classified by size (total length and depth), as well as by the type of rock in which they are formed. So, there are caves:
- limestone;
- gypsum;
- Cretaceous
- saline;
- caves in conglomerates and so on.
TOP 5 of the longest caves on the planet
Four of the five longest caves in the world are located in the United States, another in Ukraine.
Mamontov Cave (about 630 km) is the longest cave system of the Earth. It was formed in limestones 10 million years ago. Each year, the length of the cave increases, as cavers explore its new corridors.
Jewel Cave (257 km) - Located in South Dakota, near the city of Custer. Its unique feature is calcite crystals, which cover the walls of all underground corridors with a thick layer.
Optimistic Cave (231 km) - a multi-level network of labyrinths in Ukraine (in the Ternopil region), the largest underground system in Eurasia. Formed in gypsum.
Wind Cave (217 km) is another American natural wonder known for its vaulted patterns resembling a honeycomb.
Lechugia Cave (207 km) is a gypsum cave in the United States (New Mexico), the hallmark of which are unusual "luster" formations, reaching up to 5-6 meters in diameter.
Conclusion
Well, now you know the meaning of the words “karst cave”. This is an underground cavity of natural origin, which has one or more exits to the surface. All caves are classified by cavers by size, genesis mechanism, as well as by the rocks in which they are embedded (formed).