Classification of caves
libre 10
The issues of cave classification and typification of karst caves are very complicated and are currently only being developed.
The most interesting in this respect are the works of G. A. Maksimovich (1963), L. I. Maruashvili (1969) and V. N. Dublyansky (1971). The existing classifications of caves are based mainly on the consideration of morphological features of underground cavities.
They are to some extent conditional, which is due, on the one hand, to the general weakness of the study of caves, and on the other hand, to the insufficient development of the system of classification features. 
The proposed classification is a generalized scheme of the main genetic and morphological types of caves determined by a peculiar combination of morphostructural, hydrogeological and bioclimatic conditions.
Horizontal caves
According to their structure in plan, they are divided into corridor, branched and labyrinthine, which in turn are divided into straight, winding, branching, parallel, intertwined and network-like.
There are two main types of branching of karst galleries: adjunctive (convergent) and bifurcation (divergent).
Inclined caves
Inclined caves include cavities with a significant slope (from 15 to 60°), but at the same time devoid of any large vertical ledges. They are subdivided into ascending and descending caves.
Among the descending and ascending caves there are bag-shaped, inclined-gallery and inclined-stepped caves.
Vertical caves
They include wells (vertical cavities up to 50 m deep), natural mines (vertical cavity or a system of vertical cavities from 50 to 200 m deep) and abysses (a system of cavities more than 200 m deep).
According to the peculiarities of morphological structure, wells, shafts and chasms are subdivided into cylindrical, cone-shaped, slit-shaped and combined. The length of strictly vertical parts of karst caves in the Soviet Union, according to currently available data, varies from a fraction of a meter to 145 m (mine Bezdonnaya on the Chatyrdag massif of the mountainous Crimea).
The longest vertical cavity in the world is the upper part of the Pierre-Saint-Martin abyss (Pyrenees), stretching from the entrance to the Lepine grotto. Its depth is 360 meters.
Complex caves
Complex caves are characterized by a complex combination of horizontal, inclined and vertical sections. Their horizontal and vertical parts often have different origins and ages.
The Tissovaya, Krubera and Mira caves in the Mountain Crimea are interesting in this respect. The horizontal galleries of these caves are of corrosive-erosive origin, they are the remains of ancient drainage channels, currently separated by rockslides and clay deposits.
As for the vertical cavities, these are younger formations of nival-corrosive or failure (Kruber Mine) origin.
Complex caves can be subdivided into vertical-horizontal - shafts with horizontal termination; horizontal-vertical - horizontal galleries with shaft termination; complex, where horizontal, inclined and vertical cavities are combined.
Classification of cave parts
It is no less difficult task to identify individual large parts of caves and classify them.
On the basis of taking into account genetic and morphological indicators, the following classification of these forms of speleorelief can be proposed: ;
| Type | Subtype |
| Gallery | Tunnel-shaped, Canyon-shaped |
| Passage | Stairway, Gully, Crevice |
| Grotto (hall) | - |
| A well. | - |
| Organ pipe | - |
| Funnel | - |
Galleries are horizontal or inclined sections of tunnel- or canyon-shaped caves that are over 1 m wide and over 1 m high, and dozens (in some cases many hundreds) of meters long.
The most typical are tunnel-shaped galleries with flat bottoms, vertical walls and semicircular or flat vaults. Gothic galleries with lancet vaults are often found in gypsum caves.
Passages are relatively short (less than 20 m) and low (up to 1 m) sections of caves. Short (less than 1 m) passages are called passages, and low horizontal or inclined passages are called climbing passages.
Narrow (less than 0.5 m) but high or long (more than 1 m) horizontal, inclined and vertical passages are called crevices. They are usually confined to tectonic or bedding fractures.
A grotto or hallis a significantly enlarged and elevated part of the cave. Grottoes are usually located at the intersection of tectonic fractures or in areas of intense rock fracturing.
Grottoes have a variety of sizes and are generally a relative concept. The gallery, passage, organ pipe of a large cave can be much wider and higher than the grotto of a small cavity, which is an extension of a narrow crevice.
In some cases, grottoes reach enormous sizes. The largest in the Soviet Union is the grotto of the Georgian Speleologists in the Anakopi cave. It is 260 m long, 75 m wide and 50 m high. The grotto of Carlsbad Cave (USA), the largest in the world, is 1220 m long, 190 m wide and 91.5 m high.
A well is a vertical or inclined, mostly circular cavity connecting morphologically different parts of a cave.
Organ pipes are vertical cavities closed at the top and most expanded at the bottom. In some caves typical karst sinkholes are found. Galleries, grottoes, organ pipes and other large forms of speleorelief, as well as caves in general, are of heterogeneous origin.
They arise as a result of various natural processes (mainly corrosion, erosion and gravity). At the initial stages of their formation, corrosion predominates, while at later stages, mechanical destruction (erosion) and collapses play a significant role along with leaching.
Finally, small (sculptural) forms of underground relief by peculiarities of origin and morphological structure are subdivided into the following four main groups:
- Corrosive
- Erosive
- Accumulative
- Heterogeneous
| Karrs | Microterraces | Chemogenic formations | Shelves |
| Cornices | Ledges | Bridges | |
| Eruption cauldrons | Clay piles | Travertine terraces | |
| Cone-shaped hills under organ pipes, Flat bottoms of former reservoirs, Glaciogenic formations Hill-like rises composed of guano. |
A fifth group can also be distinguished, including anthropogenic forms associated with the activities of primitive people, mining, archaeological excavations, etc.
The considered classifications, of course, do not exhaust the entire diversity of karst caves and their elements, but reduce it only to some basic types.
