Tectonic structure of the Caucasus. Tectonic structure of the Caucasus Mountains

The modern tectonic structure of the Caucasus was formed about 25 million years ago during the Tertiary period. Today these are folded mountains, in which volcanoes are periodically activated due to internal geological processes. They are of the same age as the Alps and consist of gneiss, as well as granite.

general information

The tectonic structure of the Caucasus is a vast deformation zone, where the Arabian and Eurasian plates collided at the time. The mountains here were formed because of the movement of the continents. Each year, the Arabian plate, pressed by the African, moves north by a few centimeters.

For this reason, destructive earthquakes are frequent in the region, because of which the Caucasus suffers. The tectonic structure is slowly changing, causing tremors that destroy human infrastructure on the surface of the earth. For example, in 1988, a huge tragedy occurred in Armenia, in which 20,000 people died, and another 500,000 lost their homes.

Breeds

Plate plains, inclined to the north, are formed from Paleozoic crumpled rocks. They are permeated with veins from acid magma and represent giant folds. They consist of granite, quartzite and shale. In the valley of the Alikonovka River not far from Kislovodsk you can find the most ancient rocks of the ridge.

The tectonic structure of the Caucasus Mountains here brought to the surface red and pink granites, whose age is estimated at 220-230 million years. In the Mesozoic era, they were destroyed, which resulted in the formation of a layer of crust, the thickness of which 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. Inside, a mineral substance is deposited, which forms symmetrical layers. Moreover, the internal surface of such cavities can be formed from crystals, kidney-shaped crusts, sludge and other mineral aggregates. In the caucasian geodes, a rare material of celestite is sometimes found - a mineral of a transparent blue hue.

Deposits

But on the southern slopes you can find sedimentary rocks formed during the Jurassic and Cretaceous water reservoirs. Previously, there were seas, and now there are limestones of brown and yellow color, dolomites and glandular sandstones of a red shade.

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 the 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 is Small. Between them lie the plains.

The Greater Caucasus is also known as the North Caucasus (especially this term is used in Russia to refer to local republics within the federation). To the south of it is a watershed ridge. Further on lies the region known as Transcaucasia. The territory of three states is most often referred to it: Georgia, Armenia and Azerbaijan.

Also, geologists identify two more important regions: the Scythian platform and the inter-mountain zone.

Greater Caucasus

The Great Caucasus stretches for 1100 kilometers in the direction from the north-west to the south-east. Its natural boundaries are the Black and Caspian Seas. Approximate extreme points can be called Anapa in the Krasnodar Territory and Mount Ilkhydag near Azerbaijan 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 in 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. They form what is called "wings of elevation" in science. There are only two of them - northern and southern.

The first is composed of deposits in the form of folds. They are crumpled by Mesozoic and Cenozoic rocks. The young wing is formed from powerful deposits, 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. The covers and overthrusts divided them into several parts. Wings give scientists information, from which it follows that the main mountain masses of the ridge are moving to the south. Old deposits are covered by young 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 the ocean Paleotetis touched. 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 changed, internal processes made themselves felt.

Small Caucasus

The second significant ridge of the general chain. Here ends the Caucasus. The tectonic structure of this region consists of ridges, uplands of volcanic origin, and also a plateau. One of the differences from the Greater Caucasus is the absence of a single massif. On the contrary, many small ridges intersect here, because of which a large number of valleys are formed. There are no significant glaciers or majestic mountains. The reason is that the tectonically this region is very young. High peaks have not yet formed.

Here, mobile parts of the Alpine-Himalayan belt collide, because of which the Small Caucasus has a much more complex geological structure, unlike the "older brother". To the south, another plate begins. If the Northern Caucasus has almost no volcanic arcs or deflections, then there 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 corresponded to all the processes occurring here for millions of years.

Previously, this place was a tectonic seam and a huge ocean of Tethys. The local volcanic activity in the depths of the water was the most powerful on Earth in the Mesozoic era. The ocean was surrounded by several microcontinents. Over time, they finally surrounded this pool, dividing it into several parts. At the turn of 85 million years ago, a single continent was formed, which was subjected to tectonic changes many more times.

Gondwana, which moved from the north, caused huge oceanic spaces to shrink to small sizes. Also, underwater volcanoes and former borders of miniature continents have disappeared.

Scythian platform

An important part of the ridge is the Scythian young platform. It consists of two floors. Lower - this is the foundation, represented from rocks of Paleozoic origin (age 230-430 million years). The top floor is called the cover. It is younger and consists of rocks of the Mesozoic and Cenozoic eras (65-250 million years). These are marine deposits of clay and carbonate. In the middle part of the Ciscaucasia, which corresponds to the Stavropol Territory, the foundation is raised and further to the east and west begins to sink down.

Scythian platform on its southern borders ends with several deflections - Kuban, Tersky, Kusaro-Divinchensky. Here, 40 million years ago, there was a destruction of rocks, which caused the formation of molasses deposits. In these places the Caucasus is especially beautiful. The pictures of the gorges and mineral springs are breathtaking. It was these lands that Lermontov sang, being in the famous exile.

The peculiarity of the occurrence and the composition of rocks together with the structure of the earth's crust indicate that this territory was previously a sea. It was about 230 million years ago. The continental block was raised and covered with shallow water. This structure collapsed after the emergence of the Greater Caucasus. Then there appeared deflections, in the place of which colossal containers for terrestrial rocks appeared. This process continues today, than can explain the frequent cataclysms.

Intermountain Massif

It is located south of the Greater Caucasus. In the era when only the Alps were formed (about 200 million years ago), there was an uplifted element of the earth's crust. It was a carbonate platform that looked like a small continent. However, with the beginning of the formation of the mountains (30 million years ago), this area began to sag and fall down. The sea, which was in the center of the structure, gradually disintegrated on the Black Sea and the Caspian.

These are two interrelated parts. Their tectonic structure is interesting. Caucasus (the table with important information is presented below) can be divided into three segments. This is the Azerbaijan and Georgian blocks, as well as the Dzuril crystal massif, which separates them.

Study history and resources

Thanks to the multitude of internal processes, the structure of the Caucasus has allowed different natural riches to appear here. People who lived in those places in ancient times, learned how to extract and process them. Till now it is possible to find numerous traces from human activity in the forgotten mines with gold, silver, lead, copper, oil, coal, etc.

Local minerals store 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 these resources come from. The first attempts to study the geology of the Caucasus belong to the XVIII century, when scientific expeditions initiated by Lomonosov were sent here.

In the XIX century, Musin-Pushkin, Dubois de Montpere, went here for research. However, the real father of the study of geology of the Caucasus is German specialist German Abich. 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 numerous discoveries, he became an honorary member of the St. Petersburg Academy of Sciences.