Cenozoic folding of Russia

The entire modern relief of both Russia and the whole world began to form a very long time ago, at the dawn of the geological history of the Earth. The aforesaid applies to the folding of the planet - mountain ranges, hollows. It was formed over many geological eras, and also continues to change its appearance even now. In this article, we would like to focus your attention on the Cenozoic folding - the “youngest” one. And let's start with a general analysis of geological eras.

What are the foldings?

The relief of our planet is historically heterogeneous - some objects formed earlier, some millions of years later. Accordingly, all existing foldings are named for the era in which they found their appearance. Briefly get to know them.

Archean folding . The oldest - its age is 1.6 billion years. Basically, it includes platforms - a kind of "core" of the continents, their most stable and even areas.

Baikal folding . Age - 1200-500 Ma. It got its name from the name of the Russian lake, because the site where it is located formed during this period. The Baikal Plateau also includes the Brazilian Plateau, the Arabian Peninsula, the Patom Highlands, the Yenisei Ridge and so on.

Caledonian folding . Formed 500-400 million years ago. Named after Fr. Caledonia, where it was first discovered by geologists. Great Britain, eastern Australia, Scandinavia, southern China were formed in this era.

Hercynian folding . The relief formed 400-230 million ago. Here we take the Urals, most of Europe, the Great Dividing Range, Cape Mountains, Appalachian Mountains.

Mesozoic folding . Age - 65-160 million years. It was formed when dinosaurs reigned on Earth. The Russian Far East, the Cordillera appeared just then.

Alpine or Cenozoic folding took shape last. Let's talk more about her era.

Cenozoic - what is it?

Cenozoic - Cenozoic era - this is the geological era in which we live today. And it began 66 million years ago. Its border was designated by the mass extinction of biological species, which began at the end of the Cretaceous.

This name was first used in 1861 by John Phillips, an English geologist. Its short designation, which you can find in the scientific literature, is KZ. The word is formed from the merger of two ancient Greek words: καινός ("new") + ζωή ("life"). Accordingly, the "new life".

Cenozoic itself is divided within itself for several more periods:

• Paleogene (65.5-23.03 million years ago). Includes:
  • Paleocene;
  • Eocene;
  • oligocene.
• Neogene (23.03-2.59 Ma ago). Consists of two stages:
  • Miocene;
  • Pliocene.
• Quaternary period. It began 2.59 million years ago and continues to this day. So far, scientists have identified only two eras within it - the Pleistocene and the Holocene.

What is remarkable about the Cenozoic era?

What happened to geological history during the Cenozoic era? The following events are highlighted:

• Separation of New Guinea and Australia from Gondwana.
• The approach of the above arrays to Southeast Asia.
• Establishment of Antarctica at the South Pole.
• The expansion of the Atlantic Ocean.
• Continuation of continental drift, adjoining North America to South.

Transformations in the biological world also turned out to be significant:

• All animals larger than a crocodile disappeared from the face of the Earth.
• As a result of continental drift, unique bio-communities were formed on the continents.
• The onset of the era of mammals and angiosperms.
• The era of savannah, insects, flowering.
• The emergence of a new bio-species - Homo sapiens.

What is Cenozoic folding?

Alpine folding began to form 65 million years ago and is still at this stage. Its components are the youngest, and therefore the most troubled areas of the earth's crust. In areas with Cenozoic folding, mountainous reliefs are still forming - as a result of earthquakes and volcanic eruptions. Another feature is the location near the borders of lithospheric plates.

The main areas of Cenozoic folding are as follows:

• Andes.
• The Caribbean.
• Aleutian Islands.
• Asia Minor.
• Mediterranean Sea.
• Southwest Asia.
• Caucasus.
• Philippines.
• Antarctic Peninsula.
• New Zealand.
• Himalayas.
• New Guinea.
• Kuril Islands
• Kamchatka
• The Great Sunda Islands.
• Japan.

Types of folding in Russia

Mountain systems of Cenozoic folding, as well as other systems, are also widespread in our country. All geologists identified five of their varieties:

• Baikal and Early Caledonian (700-520 Ma ago):
  • Transbaikalia;
  • Baikal region;
  • Tuva;
  • East Sayan;
  • Timan and Yenisei Ridge.
• Caledonian (460-400 Ma ago):
  • Mountain Altai;
  • Western Sayan.
• Hertsinskaya (300-230 million years ago):
  • Ore Altai;
  • Ural mountains.
• Mesozoic (160-70 million years ago):
  • Sikhote-Alin;
  • northeastern part of the country.
• Young Cenozoic folding (30 million back to the present day):
  • Koryak Highlands ;
  • Caucasian relief;
  • Kurile Islands;
  • Sakhalin;
  • Kamchatka

Cenozoic folding of Russia

If we look at the map of the Russian Federation and the former Soviet Union, we notice that the Alpine folding in the south and south-west of the country includes:

• Eastern Carpathians.
• Greater Caucasus.
• Mountain Crimea.
• Pamir.
• Kopet-Dag.
• Small Balkhan.

Together, these systems are adjacent to the Alpine-Himalayan belt.

Now let's turn to the eastern part of the state. The Kuril Islands, Sakhalin, and Kamchatka can be attributed to the Cenozoic zone of the Pacific fold belt.

Let's look at the features of these systems in more detail.

Alpine-Himalayan belt: characteristic

This geological zone has a very complex structure. The main role in the latter is played by large median massifs and basins of inland seas. In their area, they are not inferior to the mountain systems of the Cenozoic folding of the belt. The latter here typically flow around the middle platforms and branch.

As for the massifs of the Alpine-Himalayan belt, they are much older than folded formations. They are mainly represented by intermountain (elevated) hills, as well as sea basins. According to geologists, they were formed in the Hercynian or even later period.

It is important to note that in the basins of the inland seas (western part of the Mediterranean Sea, southern Caspian Sea, Black Sea) of the Alpine-Himalayan belt, the earth's crust went through some degeneration and experienced a certain “oceanization”. From here today we can talk about the oceanic type of structure of the basins of the listed seas.

The relief of the Cenozoic folding is not the only component of the Alpine-Himalayan belt. Its mountain range is quite heterogeneous. We can highlight the following:

• Hercynian and older structures. I must say that over the course of history they were somewhat “reworked” by the Alpine (Cenozoic era).
• A number of Mesozoic structures.
• And, finally, Neogene and Paleogene reliefs, the formation of which, according to geologists, was in the Alpine era of the history of the Earth.

We also note here quite often developed deep faults. They divide the Alpine-Himalayan belt into blocks, which makes it possible to talk about its block structure.

Formation of the Alpine-Himalayan belt

The period of the most active development of this belt occurred in the Mesozoic and Cenozoic. In general, we can talk about its heterogeneous and heterogeneous structure.

The Alpine-Himalayan belt was formed on the site of the complexly built and large-scale Paleozian Asian-European. In some places it stands on sites and more ancient platforms. It can rightfully be called the superimposed, secondary geosynclinal belt.

As we said, at present, geologists agree that the Alpine-Himalayan belt is a rather complicated structure. Its development continues in our era - it is at an orogenic stage. For people, this is dangerous due to increased seismic activity, the eruption of volcanoes, which leads to the destruction of structures, settlements, human casualties.

Cenozoic areas in the Russian Far East

Now let's look at the specifics of the Cenozoic folding mountains in the Far East. As for the West Kamchatka system, it is a terigenic complex of the Upper Cretaceous. Overlap its paleogenic and neogenic rocks.

The central and eastern Kamchatka systems formed in the Paleogene. But large basaltic volcanoes of this area appeared in the Pliocene-Pleistocene era. What is interesting: the Eastern zone is actively formed today due to modern volcanism (28 active volcanoes).

The Kuril island arc (the Bolshaya and Malaya ridge) was formed in the Cretaceous and Quaternary. It is crushed by transverse grabens (faults, lowered areas). In front of the arc front is a deep-sea trench.

And finally, the Cenozoic folding of Sakhalin. It is divided into the western and eastern parts by the Central Kuril graben. Sakhalin is rich in coal deposits, gas and oil fields.

So we presented the mountain systems of the Cenozoic folding regions, along which the regions of Russia — the Caucasus and the Far East — are located. This geological zone is the youngest. Moreover, it is still being formed: for example, these processes in Kamchatka are very noticeable. However, they are accompanied by earthquakes and volcanism, which are dangerous for people.