The modern tectonic structure of the Caucasus was formed about 25 million years ago during the Tertiary period. Today it is folded mountains, in which volcanoes are periodically activated due to internal geological processes. They are the same age as the Alps and consist of gneiss and granite.
general information
The tectonic structure of the Caucasus is an extensive zone of deformation, where at one time there was a collision of the Arabian and Eurasian plates. Mountains formed here due to the movement of the continents. Each year, the Arabian plate, pressed by the African, moves north by several centimeters.
For this reason, destructive earthquakes are frequent in the region, because of which the Caucasus suffers. The tectonic structure is slowly changing, due to which there are shocks that destroy the human infrastructure on the surface of the earth. For example, in 1988, a tremendous tragedy occurred in Armenia, in which 20 thousand people died, and another 500 thousand lost their homes.
Breeds
The stratified plains inclined to the north are formed from Paleozoic crumpled rocks. They are pierced with veins of acidic magma and are giant folds. They are composed of granite, quartzite and schists. In the valley of the Alikonovka River near Kislovodsk, you can find the most ancient rocks of the ridge.
The tectonic structure of the Caucasus Mountains brought red and pink granites to the surface, whose age is estimated at 220-230 million years. In the Mesozoic era, they were destroyed, due to which they formed a layer of the crust, whose thickness is about 50 meters. Its composition includes feldspar, quartz and mica.
Here you can also find geodes - geological formations in the form of closed cavities in sedimentary rocks. Mineral matter is deposited inside, which forms symmetrical layers. Moreover, the inner surface of such cavities can be formed from crystals, kidney-shaped crust, sagging and other mineral aggregates. In the Caucasian geodes, a rare material celestine is sometimes found - a mineral of a transparent blue hue.
Deposits
But on the southern slopes you can find sedimentary rocks formed during the existence of the Jurassic and Cretaceous reservoirs. There used to be seas, but now there are brown and yellow limestones, dolomites and reddish ferruginous sandstones.
The structure of the Caucasus Mountains also includes deposits of various stones, for example, travertine, which appeared after the evaporation of mineral waters. In such rocks you can see distinct traces of leaves and branches that existed millions of years ago.
Structure
The tectonic structure of the Caucasus divides this mountain system into two ridges. One of them is called Big, and the other - Small. Between them lie the plains.
The Greater Caucasus is also known as the North Caucasus (this term is most often used in Russia to refer to local republics within a federation). South of it is a dividing ridge. Even further lies the region known as Transcaucasia. The territory of three states is most often referred to it: Georgia, Armenia and Azerbaijan.
Geologists also distinguish two more important regions: the Scythian platform and the intermountain zone.
Greater Caucasus
The Greater Caucasus extends for 1,100 kilometers in a direction from the northwest to the southeast. Its natural borders are the Black and Caspian Seas. Approximate extreme points can be called Anapa in the Krasnodar Territory and Mount Ilkhydag not far from Azerbaijani Baku.
This mountain system is divided into several parts. The watershed ridge (or the Main Caucasus) has a height of 3 to 5 thousand meters. Here are the highest peaks of Europe. The tectonic structure of the Caucasus formed majestic landscapes.
The mountain structure of this massif consists of a crystalline basement of ancient age - this is the main ridge. Its core is surrounded by a young cover, consisting of new breeds. It is they who form what is called “wings of uplift” in science. There are two of them - northern and southern.
The first is composed of folds. They are crushed by rocks of the Mesozoic and Cenozoic age. The young wing is formed from thick sediments, which are the cause of great geological stress in this region. The structure is such that the rocks remain crumpled into complex and numerous folds. Veils and thrusts broke them into several parts. The wings give scientists information from which it follows that the main mountain masses of the ridge are moving south. Old sediments are covered by young ones and hide under the waters of the Azov, Black and Caspian seas.
In the Paleozoic era, the northern part of the Caucasus was the outskirts, where the continent and ocean of Paleotetis were in contact. At first it was a calm region without volcanic or geological activity in the type by which the Atlantic now exists. However, over time, the situation has changed, internal processes have made themselves felt.
Lesser Caucasus
The second significant ridge of the common chain. This is where the Caucasus ends. The tectonic structure of this region consists of ridges, uplands of volcanic origin, as well as a plateau. One of the differences from the Greater Caucasus is the lack of a single array. On the contrary, many small ridges intersect here, due to which a large number of valleys are formed. There are no significant glaciers or majestic mountains. The reason is that tectonically this region is very young. High peaks have not yet formed.
Here the moving parts of the Alpine-Himalayan belt collide, which is why the Lesser Caucasus has a much more complex geological structure, in contrast to the “elder brother”. South begins another plate. If the North Caucasus has almost no volcanic arches or deflections, then here they are an order of magnitude more.
Geological history of the region
The geological history of the Lesser Caucasus can be described by several features that correspond to all the processes that have been happening here for millions of years.
Previously, a tectonic seam and a huge Tethys ocean lay on this site. The local volcanic activity in the depths of the waters was the most powerful on Earth in the Mesozoic era. The ocean was surrounded by several microcontinent. Over time, they finally surrounded this pool, dividing it into several parts. At the turn of 85 million years ago, a single continent formed, which was many times subjected to tectonic changes.
Gondwana, which moved from the north, caused the vast oceanic spaces to shrink to small sizes. Underwater volcanoes and the former borders of miniature continents also disappeared.
Scythian platform
An important part of the ridge is the Scythian young platform. It has two floors. The lower one is the foundation represented by rocks of Paleozoic origin (230-430 million years old). The upper floor is called a cover. It is younger and consists of rocks of the Mesozoic and Cenozoic era (65-250 million years). These are marine deposits of clay and carbonate. In the middle part of Ciscaucasia, which corresponds to the Stavropol Territory, the foundation rises and further to the east and west it begins to plunge down.
The Scythian platform at its southern borders ends with several troughs - the Kuban, Tersky, Kusaro-Divichensky. Here, 40 million years ago, rock destruction occurred, due to which the strata of molasses deposits formed. The Caucasus is especially beautiful in these places. Photos of the local gorges and mineral springs are breathtaking. It was these lands that Lermontov sang while in the famous exile.
The peculiarity of the occurrence and composition of the rocks along with the structure of the earth's crust suggests that this territory used to be a sea. It was about 230 million years ago. The continental block was elevated and covered in shallow water. This structure collapsed after the emergence of the Greater Caucasus. Then there were troughs, on the site of which colossal containers for terrestrial rocks appeared. This process continues today, which can explain the frequent disasters.
Intermountain massif
It is located south of the Greater Caucasus. In the era when the Alps were just formed (about 200 million years ago), there was a raised element of the earth's crust. It was a carbonate platform, like a small mainland. However, with the formation of mountains (30 million years ago), this area began to cave in and go down. The sea, which was in the center of the structure, gradually broke up into the Black Sea and the Caspian.
These are two interconnected parts. Their tectonic structure is interesting. The Caucasus (a table with important information is presented below) can be divided into three segments. This is a block of Azerbaijan and Georgia, as well as the Dzirul crystalline massif separating them.
Learning History and Resources
Thanks to many internal processes, the structure of the Caucasus has allowed various natural resources to appear here. People who lived in those places in antiquity learned how to mine and process them. You can still find numerous traces of human activity in forgotten mines with gold, silver, lead, copper, oil, coal, etc.
Local subsoil stores about 200 billion barrels of oil, as well as natural gas. These are large reserves, which will last for several decades.
Interest in the structure of this land has always existed - people wanted to understand where such resources came from. The first attempts to study the geology of the Caucasus date back to the 18th century, when scientific expeditions initiated by Lomonosov set off here.
In the XIX century, people left here for research Musin-Pushkin, Dubois de Montpere. However, the German father German Abich is rightfully considered the real father of studying the geology of the Caucasus. He took Russian citizenship and often traveled to the south of the country in the 60s of the XIX century. The subject of his study was the tectonic structure of the Caucasus Mountains. For his many discoveries, he became an honorary member of the St. Petersburg Academy of Sciences.