Caves are of great interest not only to researchers, but also to curious people, because this topic is rather multi-faceted.
Let’s begin with the fact that there are several types of caves, such as tectonic – formed in places of tectonic faults, volcanic – which are formed when the cooling lava flow is covered with crust, resulting in a lava tube. Inside this tube lava continues to flow for some time, which leads to cavity formation. But undoubtedly, the most numerous group is the karst caves.
Karst formation is associated with a so-called cascade of carbon dioxide. This process occurs when the surface of the soil around the cracks is destroyed by carbon dioxide water, especially carbonate soils such as limestone and gypsum are dissolved.
The variety and uniqueness of these natural creations is truly inexhaustible. The most famous and one of the largest karst caves – Mammoth in the U.S., in fact, is rather a whole system of combined caves, formed in the limestone layer.
There are also quite unique formations here, such as the Moviele Cave in Romania, formed as a result of the impact on the rock of sulfuric acid, in addition, there is an absolutely closed ecosystem, isolated from the environment.
And a strange cave of crystals in Mexico, where there are giant crystals of selenite – a mineral of structural type of gypsum, the largest of which reaches 11 meters in length, 4 meters in width and weighs about 55 tons. There are also extreme conditions in the cave: the temperature is 58 degrees Celsius with humidity of 90%.
By the way, there are karst not only caves, there are also failures, mines and wells. The latter occur when leaching rocks with leaking water and, in fact, are vertical caves.
Probably the most famous of the karst wells is the sacred senate in Mexico, which is a giant sinkhole, 60 meters in diameter, with steep walls of limestone, steeply falling down to the water. The Maya thought it was inhabited by the rain god Chuck, to whom various offerings and sacrifices were made. While investigating the bottom, archaeologists found a huge number of gold and jade ornaments that were thrown into this abyss to propitiate the god.
Interestingly, as a result of cave destruction, karst lakes appear. Thus, huge underground caves in Croatia gave life to two lakes at once, the Blue and Red, by the way, if the first one got its name for the color of water, then the second one is due to the color of coastal rocks, which have a red-brown tint due to the presence of iron oxide in them.
Karst origin has the widely known Blue Lake in Abkhazia, and the spectacular blue color of its water directly depends on the limestone reservoir forming the wall.
It is also worth mentioning the pseudo karst. It is divided into thermo karst, associated with the melting of frozen rocks in the permafrost, and clay karst, which arises in a strongly carbonate loams in the presence of cracks on the surface.
The uniqueness of speleofauna, the importance of caves in the preservation and conservation of the remains of ancient people and animals make them a real laboratory for scientists of various directions, and the discovery there is far from over.