por What is karst erosion?
The karst erosion it is one of the types of erosion that can be found in the environment. This natural process occurs thanks to the action of a stream of water that has certain levels of acidity.
The circulation of water on the surface of a limestone rock causes, with the prolonged passage of time, modifications to the structure. This type of process can occur both on the earth’s surface and in the subsoil.
There are different types of karstic erosion, which directly derives in the type of forms that can be generated on the surface of the rock on which the body of water circulates.
Two examples of this type of natural phenomena are the Torcal de Antequera, located in Spain, and the Grutas de Cacahuamilpa National Park, located in Mexico.
Karst processes
Due to the acidification of the water
The karstification process occurs when a water source, which contains a certain level of acidity, indirectly causes the dissolution of calcium carbon found in limestone rocks.
Acidification of water occurs when, thanks to direct contact with other surfaces, it obtains a greater amount of carbon dioxide.
The need for acidic water to be present to dissolve a rock varies depending on the type of stone. An example of this are evaporites, which do not require this type of liquid to undergo a change in their shape.
due to the evaporation of water
Another way in which the shapes of rocks can change thanks to the action of water is through evaporation.
A body of water containing gas and calcium bicarbonate is capable of reaching a cavity larger than the fissures through which it previously passed. Once in place, the liquid can experience a slow evaporation that causes the salts dissolved in it to crystallize due to certain circumstances.
The action of water can cause a drip inside a cave, which allows the formation of stalactites on the ceiling and stalagmites on the floor: columns that can form geodes when joined.
Types of karst erosion
exokarst erosion
Karst erosion occurs on the earth’s surface. This type of geological formation is divided into several subtypes: lapiaces, poljés, sinkholes and canyons.
lapiaces or lenares
This type of erosion presents defined characteristics: the influence of water on the rocks produces the formation of grooves or cavities that are separated by thin walls.
The lapiaces tend to appear abroad, specifically in limestone or gypsum outcrops, which are affected by karstic erosion when the water exceeds its flow on the slopes or on flat surfaces that have fissures.
Poljés
It is a valley that has a large size and that has irregular contours, surrounded by steep edges where there are limestone rock formations. This depression occurs in a massif of karstic rock that has significant dimensions.
The poljés are formed by the dissolution of limestone blocks and commonly you can see a slight flow of water that disappears through an opening in the ground. For this reason, on some occasions the excess of this liquid can cause the flooding of the space, which gives rise to a lake.
Torcas or sinkholes
Also known as sinkholes, this type of formation is characterized by being produced in those places where a body of water stagnates. They are usually generated on surfaces that have a formation of limestone rock and clay in different proportions.
Torcas can have a variety of shapes and, in some cases, can be joined together by the action of karstic erosion.
Canyon
This type of geological formations occurs when the current of a river causes the erosion of land, which gives rise to a deep cleft that has almost vertical walls.
The canyons, also known as gorges, can be generated by the action of a river current and a karstification process.
endokarstic erosion
Endokarstic erosion occurs inside the earth’s surface. Two of the geological formations that exist of this type are sinkholes and chasms.
sinkholes
Sinkholes are formed when flowing water with slight levels of acidity slowly erodes limestone soils and subsequently seeps into them. This process allows the formation of an underground cave over time.
At a certain point in the process, the accumulation of water on the surface causes the cavern floor to collapse, giving way to a kind of sinkhole.
If more
This type of geological formations are a cavity or cave that is formed by a process of karstic erosion. It can also be generated by the collapse of the roof of a cavity, a space through which a stream of water can filter into the interior of the cave.
It is a cavity that has an opening on the surface through which a slight current of water enters.
Examples of karst formations
Torcal de Antequera
El Torcal de Antequera is located in the province of Malaga, Spain. It is located in a geological formation in which the action of water contributed to the limestone rocks adopting diverse and attractive shapes.
El Torcal de Antequera is a protected natural area and a place of great tourist interest. ANDIt is made up of different types of limestone rocks, which originated from the seabed millions of years ago, during the Jurassic period.
Sediments from the bottom of the sea coalesced and were subsequently raised above the surface by the different movements of the tectonic layers. With the passage of time, cracks in the structure and a series of failures occurred. Erosion, for its part, gave it the characteristic appearance it currently has.
Grutas de Cacahuamilpa National Park
With an important tourist attraction, this natural space is located in the state of Guerrero, Mexico. It is a protected natural area and is considered one of the most amazing caves in the world, for containing stones and rocks of the most whimsical shapes.
References
Karst. Retrieved from nationalgeographic.org.
Living on Karst. Recovered from dcr.virginia.gov.