Formation and disintegration of the Rodinium supercontinent. Continents and continents Proposed location of the continents

Continent(from lat. continens, genitive case continentis) - a large massif of the earth's crust, a significant part of which is located above the level of the world ocean (land), and the rest of the peripheral part is below ocean level. The continent also includes islands located on the underwater periphery. In addition to the concept of a continent, the term mainland is also used.

Terminology

Mainland- a vast expanse of land washed by the seas and oceans (or Land, land - as opposed to water or islands). In Russian, the words mainland and continent have the same meaning.

From a tectonic point of view, continents are sections of the lithosphere that have a continental structure of the earth's crust.

There are several continental models in the world (see below). On the territory of the post-Soviet space, the model of six continents with a divided America is adopted as the main one.

There is also a similar concept of part of the world. The division into continents is made on the basis of separation by water space, and parts of the world are rather a historical and cultural concept. Thus, the continent of Eurasia consists of two parts of the world - Europe and Asia. And part of the world America is located on two continents - South America and North America. In other cases, parts of the world coincide with the above continents.

The border between Europe and Asia runs along the Ural Mountains, then the Ural River to the Caspian Sea, the Kuma and Manych rivers to the mouth of the Don River and further along the shores of the Black and Mediterranean Seas. The Europe-Asia border described above is not indisputable. This is just one of several options accepted in the world.

In geology, the continent is also often referred to as the underwater margin of the continent, including the islands located on it.

In English and some other languages, the word continent denotes both continents and parts of the world.

Continental models

In the world, different countries estimate the number of continents differently. Number of continents in different traditions

• 4 continents: Afro-Eurasia, America, Antarctica, Australia
• 5 continents: Africa, Eurasia, America, Antarctica, Australia
• 6 continents: Africa, Europe, Asia, America, Antarctica, Australia
• 6 continents: Africa, Eurasia, North America, South America, Antarctica, Australia
• 7 continents: Africa, Europe, Asia, North America, South America, Antarctica, Australia

The seven continents model is popular in China, India, partly in Western Europe and in English-speaking countries.

The six continent model with America united (we call it "Parts of the World") is popular in Spanish speaking countries and parts of Eastern Europe including Greece with its five continent model (five populated continents).

Comparison of area and population

- the largest and only continent on Earth, washed by four oceans: in the south - the Indian, in the north - the Arctic, in the west - the Atlantic, in the east - the Pacific. The continent is located in the Northern Hemisphere between approximately 9° W. and 169° W. while some of the Eurasian islands are located in the Southern Hemisphere. Most of continental Eurasia lies in the Eastern Hemisphere, although the extreme western and eastern ends of the mainland are in the Western Hemisphere. Eurasia stretches from west to east for 10.5 thousand km, from north to south - for 5.3 thousand km, with an area of ​​53.6 million km2. This is more than a third of the total land area of ​​the planet. The area of ​​the Eurasian islands is approaching 2.75 million km2.

Contains two parts of the world: Europe and Asia. The border line between Europe and Asia is most often drawn along the eastern slopes of the Ural Mountains, the Ural River, the Emba River, the northwestern coast of the Caspian Sea, the Kuma River, the Kuma-Manych Depression, the Manych River, the eastern coast of the Black Sea, the southern coast of the Black Sea, the Strait Bosphorus, the Sea of ​​Marmara, the Dardanelles, the Aegean and Mediterranean Seas, the Strait of Gibraltar. This division has developed historically. Naturally, there is no sharp boundary between Europe and Asia. The continent is united by the continuity of land, the current tectonic consolidation and the unity of numerous climatic processes.

(English North America, French Amérique du Nord, Spanish América del Norte, Norteamérica, Ast. Ixachitlān Mictlāmpa) is one of the continents of planet Earth, located in the north of the Western Hemisphere of the Earth. North America is washed from the west by the Pacific Ocean with the Bering Sea, Alaska and California bays, from the east by the Atlantic Ocean with the Labrador, Caribbean, St. Lawrence and Mexican seas, from the north by the Arctic Ocean with the Beaufort, Baffin, Greenland and Hudson Bay seas. From the west, the continent is separated from Eurasia by the Bering Strait. In the south, the border between North and South America runs through the Isthmus of Panama.

North America also includes numerous islands: Greenland, the Canadian Arctic Archipelago, the Aleutian Islands, Vancouver Island, the Alexander Archipelago and others. The area of ​​North America, together with the islands, is 24.25 million km2, without the islands, 20.36 million km2.

(Spanish América del Sur, Sudamérica, Suramérica, port. América do Sul, English South America, Dutch Zuid-Amerika, French Amérique du Sud, Guar. Ñembyamérika, Quechua Urin Awya Yala, Urin Amerika) - the southern continent in America, located mainly in the Western and Southern hemispheres of planet Earth, however, part of the continent is also located in the Northern Hemisphere. It is washed in the west by the Pacific Ocean, in the east by the Atlantic, from the north it is limited by North America, the border between the Americas runs along the Isthmus of Panama and the Caribbean Sea.

South America also includes various islands, most of which belong to the countries of the continent. Caribbean territories belong to North America. The South American countries that border the Caribbean - including Colombia, Venezuela, Guyana, Suriname and French Guiana - are known as Caribbean South America.

The most important river systems in South America are the Amazon, Orinoco and Parana, with a total basin of 7,000,000 km2 (the area of ​​South America is 17,800,000 km2). Most of the lakes in South America are located in the Andes, the largest of which and the world's highest navigable lake is Titicaca, on the border of Bolivia and Peru. The largest in area is Lake Maracaibo in Venezuela, it is also one of the oldest on the planet.

Angel Falls, the highest waterfall in the world, is located in South America. On the mainland, there is also the most powerful waterfall - Iguazu.

- the second largest continent on our planet Earth after Eurasia, washed by the Mediterranean Sea from the north, the Red Sea from the northeast, the Atlantic Ocean from the west and the Indian Ocean from the east and south.

Africa is also called the part of the world, consisting of the mainland Africa and the islands adjacent to it, the largest of which is the island of Madagascar.

The African continent crosses the equator and several climatic zones; its feature is that it is the only continent that stretches from the northern subtropical climatic zone to the southern subtropical one.

Due to the lack of constant rainfall and irrigation on the continent - as well as glaciers or the aquifer of mountain systems - there is practically no natural regulation of the climate anywhere, except for the coasts.

(from Latin australis - "southern") - a continent located in the Eastern and Southern hemispheres of our planet Earth.

The entire territory of the mainland is the main part of the state of the Commonwealth of Australia. The mainland is part of the world Australia and Oceania.

The northern and eastern coasts of Australia are washed by the Pacific Ocean: the Arafura, Coral, Tasman, Timor Seas; western and southern - the Indian Ocean.

Near Australia are the large islands of New Guinea and Tasmania.

Along the northeast coast of Australia, the world's largest coral reef, the Great Barrier Reef, stretches for more than 2,000 km.

(Greek ἀνταρκτικός - the opposite of Arctida) - a continent located in the very south of the Earth, the center of Antarctica approximately coincides with the geographic south pole. Antarctica is washed by the waters of the Southern Ocean. Antarctica is also called the part of the world, consisting of the mainland of Antarctica and adjacent islands.

Antarctica is the highest continent, its average height is 2040 meters. About 85% of the planet's glaciers are also located on the mainland. There is no permanent population on Antarctica, but there are more than forty scientific stations belonging to different states and intended for research and detailed study of the features of the continent.

Antarctica is almost completely covered by an ice sheet, the average thickness of which exceeds 2500 meters. There is also a large number of subglacial lakes (more than 140), the largest of which is Lake Vostok discovered by Russian scientists in the 1990s.

Hypothetical continents

Kenorland

Kenorland is a hypothetical supercontinent that, according to geophysicists, existed in the Neoarchean (about 2.75 billion years ago). The name comes from the Kenoran phase of folding. Paleomagnetic studies indicate that Kenorland was at low latitudes.

Nuna

Nuna (Columbia, Hudsonland) is a hypothetical supercontinent that existed in the period from 1.8 to 1.5 billion years ago (maximum assembly ~ 1.8 billion years ago). The assumption of its existence was put forward by J. Rogers and M. Santosh in 2002. Nuna's existence dates back to the Paleoproterozoic era, making it supposedly the oldest supercontinent. It consisted of plateau precursors of ancient platforms that were part of the earlier continents of Laurentia, Fennosarmatia, the Ukrainian Shield, Amazonia, Australia, and possibly Siberia, the Sino-Korean platform and the Kalahari platform. The existence of the Columbia continent is based on geological and paleomagnetic data.

Rodinia

Rodinia (from Rus. Rodina or from Rus. give birth) is a hypothetical supercontinent that presumably existed in the Proterozoic - the Precambrian eon. It originated about 1.1 billion years ago and broke up about 750 million years ago. At that time, the Earth consisted of one giant piece of land and one giant ocean, which received the name Mirovia, also taken from the Russian language. Rodinia is often considered the oldest known supercontinent, but its position and shape is still a matter of controversy. After the collapse of Rodinia, the continents managed to once again unite into the supercontinent Pangea and disintegrate again.

Lavrussia

Laurussia (Euramerica) is a Paleozoic supercontinent formed as a result of the collision of the North American (the ancient continent of Laurentia) and the East European (the ancient continent of Baltica) platforms during the Caledonian orogeny. Also known are the names Caledonia, Old Red Continent, Old Red Sandstone Continent. In the Permian period, it merged with Pangea and became its integral part. After the collapse of Pangea, it became part of Laurasia. Broken up in the Paleogene.

gondwana

Gondwana in paleogeography is an ancient supercontinent that arose approximately 750-530 million years ago, was localized around the South Pole for a long time, and included almost all the land that is now located in the southern hemisphere (Africa, South America, Antarctica, Australia), as well as tectonic blocks of Hindustan and Arabia, now moved to the northern hemisphere and become part of the Eurasian continent. In the early Paleozoic, Gondwana gradually shifted north and in the Carboniferous (360 million years ago) joined with the North American-Scandinavian continent to form the giant protocontinent Pangea. Then, during the Jurassic period (about 180 million years ago), Pangea split again into Gondwana and the northern continent of Laurasia, which were separated by the Tethys Ocean. 30 million years later, in the same Jurassic period, Gondwana gradually began to break up into new (current) continents. Finally, all modern continents: Africa, South America, Australia, Antarctica and the Hindustan Peninsula stood out from Gondwana only at the end of the Cretaceous period, that is, 70-80 million years ago.

Pangea

Pangea (ancient Greek Πανγαῖα - “all-earth”) is the name given by Alfred Wegener to the protocontinent that arose in the Paleozoic era. The giant ocean, which washed Pangea from the Silurian period of the Paleozoic to the early Mesozoic inclusive, received the name Panthalassa (from other Greek παν- “all-” and θάλασσα “sea”). Pangea was formed in the Permian period, and split at the end of the Triassic (about 200 - 210 million years ago) into two continents: the northern continent - Laurasia and the southern continent - Gondwana. In the process of the formation of Pangea from more ancient continents, mountain systems arose at the places of their collision, some of them have existed to this day, for example, the Urals or the Appalachians. These early mountains are much older than the younger mountain systems (the Alps in Europe, the Cordillera in North America, the Andes in South America or the Himalayas in Asia). Due to the erosion that lasts for many millions of years, the Urals and the Appalachians are run-in low mountains.

Kazakhstan

Kazakhstania - the Middle Paleozoic continent, which was located between Laurussia and the Siberian platform. It stretches from the Turgai trough and the Turan lowland to the Gobi and Takla-Makan deserts.

Laurasia

Laurasia is a supercontinent that existed as the northern part of the fault of the Pangea protocontinent (southern - Gondwana) in the late Mesozoic era. It united most of those territories that today make up the existing continents of the Northern Hemisphere - Eurasia and North America, which in turn broke away from each other from 135 to 200 million years ago.

Pangea Ultima

It is assumed that in the future the continents will once again gather into a supercontinent called Pangea Ultima.

(Visited 17 640 times, 10 visits today)

Also taken from Russian. Rodinia is often considered the oldest known supercontinent, but its position and shape is still a matter of controversy. Geophysicists suggest that other supercontinents existed before Rodinia: Kenorland - maximum assembly ~ 2.75 billion years ago, Nuna (Columbia, Hudsonland) - maximum assembly ~ 1.8 billion years ago. After the collapse of Rodinia, the continents merged into the supercontinent Pannotia. After the collapse of Pannotia, the continents merged into the supercontinent Pangea and disintegrated again.

It is assumed that in the future the continents will once again gather into a supercontinent called Pangea Ultima.

Estimated location of the continents

Noticeable coincidences at the edges of the plates of South America and Antarctica suggest that these two continents were connected in the Proterozoic. To the north of them were, apparently, Australia and India. North America with Greenland communicated with Europe. During the collision of Europe and Asia, the Ural Mountains arose, which today are one of the oldest mountain ranges and, due to erosion, have an incomparably lower height than after formation.

According to one of the paleoclimatic reconstructions (the “Snowball Earth” hypothesis, common in modern science), during the existence of Rodinia, that is, about 850-635 million years ago, a global ice age began on the planet, which ended only when Rodinia split. The geochronological period, called cryogeny, was presumably characterized by the fact that most of Rodinia was located near the equator. In the Ediacaran, 600 million years ago, when the fragments of Rodinia dispersed to the poles, multicellular simple life began to develop on them, and Mirovia turned into the Panthalassa and Pan African oceans.

In February 2013, an article was published in the journal Nature Geoscience, which reported that geologists had discovered sand containing zircon minerals on the island of Mauritius in the Indian Ocean, which could indirectly be considered the remains of Rodinia.

see also

Write a review on the article "Rodinia"

Notes

Links

• []

An excerpt characterizing Rodinia

Everything I heard from the lips of the North once again flooded my heart with sadness ... I asked myself again and again - are all these irreparable losses really natural? .. Is there really no way to rid the world of evil spirits and malice ?!. All this terrible machine of global killing made the blood run cold, leaving no hope of salvation. But at the same time, a powerful stream of life-giving force flowed from somewhere into my wounded soul, opening every cell in it, every breath to fight traitors, cowards and scoundrels! .. With those who killed the pure and brave, without hesitation, by any means, if only to destroy everyone who could be dangerous for them ...

Civilization arose 1 billion years ago - the beginning.
Civilization ceased to resist the aggressively changed environment 750 million years ago - the end.
::::::::::::::::::::::::::::::::::::::::::::::::::::
200 million years after the collapse of Megagea, the fourth overtone began, which led 1000 million years ago (at the beginning of the Late Riphean) to the appearance of the supercontinent Rodinia (Mesogea). Rodinia formed in the southern hemisphere. It included the new Central Asian continent, which included the territories of the modern Karakorum, Hindu Kush, Pamir (having an Archean core), the Iranian Highlands, the Tien Shan, as well as Kokshetau, Betpakdala, Ulytau, Mangyshlak and Ustyurt. The continent was at that time a high plateau with numerous volcanoes.

+++++++++++++++++++++++++++++++++++++++

Wand its 300-million-year history, Rodinia experienced many violent tectonic events, among which the most grandiose was the movement of East Gondwana (East Antarctica, Western Australia and India), which broke away from North America 750 million years ago, and its reattachment 150 million years later to Rodinia from Africa.

7 50 million years ago, the disintegration of Rodinia, which dragged on for 150 - 200 million years, began with the formation of the oceans of the Paleoasian, Paleoyapetus, Paleotethys and Paleopacific.

ATCentral Kazakhstan has preserved traces of the rift in the form of molasses (detrital material from the sides of the rift or from the mountains) that broke away from Rodinia Kokshetau, the Northern Tien Shan and the Kazakh upland. The latter, in the Vendian, as a result of the development of rifts, was a complex archipelago with internal shallow seas on the continental crust and deep-sea seas that arose on the site of rifts on the oceanic crust.

ATwhile Rodinia continued to disintegrate in the Vendian, the opposite process of consolidation (collision) of the South American and African continental plates began to proceed in the southwest with the formation of a new continent, Western Gondwana. Later, the island of Madagascar (having an Archean core) and East Gondwana joined Western Gondwana. A unified Gondwana formed in the middle of the fifth overton, that is, by the beginning of the Cambrian, the first period of the Paleozoic era 540 million years ago.

ATlate Riphean (1050-630 million years ago) and early Vendian (630-580 million years ago) there were two major ice ages that bound the entire planet with ice, united by one name - Snowball. Both glacial epochs are distinguished by tillite deposits, which are overlain by limestones and dolomites, which indicates a sharp warming of the climate. The reason for such strong glaciations remains unclear (maybe the Sun's orbit was crossed by a giant dust cloud that absorbed part of the solar heat), but a convincing hypothesis is put forward about what caused the warming. This is an increase in volcanic activity. Volcanoes emitted carbon dioxide, among other gases, into the atmosphere, which trapped heat reflected from the earth's surface and released by the planet itself.

BUTchronological forecaster Travin A.A.

2 .5-2.4 billion ago. The first supercontinent is Monogaea.

2 .2 billion ago. The collapse of Monogaea.

1 .8 billion ago. A new supercontinent is formed - Megagea.

1 .4 billion ago. The collapse of Megagea.

1 billion ago. The supercontinent Mesogea, which gradually arose as a result of the convergence of blocks of the previously disintegrated Megagea

8 00-750 million ago. Breakup of Mesogea into Laurasia and Gondwana.

6 50 million ago. Collapse of Laurasia and Gondwana.

20 0 million ago. Again the supercontinent (in the past - the last one) - Pangea.

6 0 million ago. Collapse of Pangea

5 0 million in the future. Forecast. The Atlantic and Indian Oceans will become much wider. Accordingly, the area of ​​the Pacific Ocean will decrease. North and South America will shift to the west, Africa to the northeast, Europe, Asia, including India, to the east, Australia to the north (reach the equator), and only Antarctica will hardly change its position in relation to the South Pole .

++++++++++++++++++++

In early 2013, geologists found evidence that under the ocean, between Madagascar and India, the submerged remains of an ancient microcontinent are scattered.

The proof was a find in Mauritius, a volcanic island lying about 900 km east of Madagascar. The oldest basalts there are about 8.9 million years old, says geologist Bjorn Jamtveit from the University of Oslo (Norway). But a careful analysis of sand from two local beaches revealed about twenty zircons - zirconium silicate crystals that are highly resistant to erosion and chemical changes. They are much older.

These zircons were formed in granites and other volcanic rocks at least 660 million years ago. One of the crystals is at least 1.97 billion years old.

Mr. Yamtveit and his colleagues suggest that the rocks containing these zircons originated in fragments of ancient continental crust under Mauritius. It seems that relatively recent volcanic eruptions have brought fragments of the crust to the surface, where the zircons have been eroded into the sand.

Researchers also suspect that many fragments of that continental crust lie under the bottom of the Indian Ocean. An analysis of the Earth's gravitational field has revealed several areas where the oceanic crust is much thicker than usual - 25-30 km instead of the usual 5-10 km.

This anomaly may be the remnants of the land, which scientists propose to call Mauritia (Mauritia). It likely split from Madagascar when tectonic rifting and stretching of the seafloor caused the Indian subcontinent to move from the southern Indian Ocean in a northeasterly direction. The subsequent stretching and thinning of the crust in this area led to the subsidence of fragments of Mauritia, which at that time consisted of an island or archipelago with a total area of ​​\u200b\u200babout three Cretes.

The scientists chose sand, rather than local rocks, to analyze, to ensure that zircons that were inadvertently stuck in crushing equipment from previous studies did not contaminate fresh samples.

“We found zircon in the sand,” says University of Oslo professor Trond Torsvik, who led the study, “which is normally found in continental crust. Moreover, the zircons we found are very, very ancient.”

The nearest outcrop of continental crust where Mauritian zircons can still be found is deep underwater. In addition, zircons were mined in places in Mauritius where people almost never go and could hardly bring them with them. At the same time, the crystals are too large to be carried there by the wind.

Approximately 85 million years ago, leads BBC Professor Torsvik's words, when India began to separate from Madagascar, the microcontinent broke and went under water. Only minor remnants of it have survived, for example, the Seychelles.

“We need data of a seismological nature to get information about the geological structure of the rock at the bottom of the ocean,” Professor Torsvik explained.

“Or you can start excavations at the bottom of the ocean, but it will cost enormous money,” he stressed.

Rodinia is a supercontinent believed to have formed about a billion years ago. At that time, the Earth consisted of one giant piece of land and one giant ocean. Rodinia is considered the oldest known supercontinent, but its position and outlines are still the subject of controversy among scientists and experts.

Here is the most common version:

Once upon a time we could (if we lived at that time, of course) walk from Australia to North America. Many beings living at that time made such transitions more than once. While heavy iron-bearing rocks sank deeper, forming a core over several hundred million years, light stony rocks, rising to the surface, formed a crust. Gravitational contraction and radioactive decay further heated the interior of the Earth. In connection with the increase in temperature from the surface to the center of our planet, foci of tension arose at the boundary with the crust (where the convective rings of mantle matter converge into an upward flow.)

Under the influence of mantle currents, lithospheric plates are in constant motion, hence volcanoes, earthquakes and continental drift arise. The continents are constantly moving relative to each other, but since the rate of their displacement is about 1 centimeter per year, we do not notice this movement. Nevertheless, if we compare the positions of the continents in billions of years, the shifts become tangible. The theory of continental drift was first put forward in 1912 by the German geographer Alfred Wegener, when he noticed that the borders of Africa and South America are similar, like pieces of the same mosaic. Later, after exploring the bottom of the ocean, his theory was confirmed. In addition, it was concluded that the North and South magnetic poles have changed places 16 times over the past 10 million years! Our planet was formed gradually: much that was before disappeared, and now there is something that was absent in the past. Not immediately free oxygen appeared on the planet. Before the Proterozoic, despite the fact that there was already life on the planet, the atmosphere consisted only of carbon dioxide, hydrogen sulfide, methane and ammonia. Scientists have found the oldest deposits, clearly not subjected to oxidation.

For example, river pebbles from pyrite, which reacts well with oxygen. If this did not happen, then there was no oxygen by that time. In addition, 2 billion years ago, there were no potential sources capable of producing oxygen at all. To this day, photosynthetic organisms are the only source of oxygen in the atmosphere. At the beginning of the Earth's history, the oxygen produced by Archean anaerobic microorganisms was almost immediately spent on the oxidation of dissolved compounds, rocks and gases in the atmosphere. Molecular oxygen was almost non-existent; by the way, it was poisonous to most of the organisms that existed at that time. By the beginning of the Paleoproterozoic era, all surface rocks and gases in the atmosphere had already been oxidized, and oxygen remained in the atmosphere in a free form, which led to an oxygen catastrophe. Its significance is that it has globally changed the position of communities on the planet.

If earlier most of the Earth was inhabited by anaerobic organisms, that is, those that do not need oxygen and for which it is poisonous, now these organisms have faded into the background. The first place was taken by those who used to be in the minority: aerobic organisms, which previously existed only in a negligible space of accumulation of free oxygen, were now able to "settle" throughout the planet, with the exception of those small areas where there was not enough oxygen. An ozone screen formed over the nitrogen-oxygen atmosphere, and cosmic rays almost stopped penetrating the Earth's surface. The consequence of this is a decrease in the greenhouse effect and global climate change. 1.1 billion years ago, there was one giant continent on our planet - Rodinia (from Russian Rodina) and one ocean - Mirovia (from Russian world). This period is called the "Ice World", as it was very cold on our planet at that time. Rodinia is considered the oldest continent on the planet, but there are suggestions that other continents existed before it.

Rodinia broke up 750 million years ago, apparently due to upward heat flows in the Earth's mantle, which blew up areas of the supercontinent, stretching the crust and causing it to break in those places. Although living organisms existed before the break of Rodinia, but only in the Cambrian period did animals begin to appear with a mineral skeleton that came to replace soft bodies. This time is sometimes called the "Cambrian explosion", at the same moment the next supercontinent - Pangea (Greek Πανγαία - all-earth) was formed. Most recently, 150-220 million years ago (and for the Earth this is a very insignificant age), Pangea broke up into Gondwana, "collected" from modern South America, Africa, Antarctica, Australia and the Hindustan island, and Laurasia - the second supercontinent, consisting of Eurasia and North America. After tens of millions of years, Laurasia split into Eurasia and North America, which, as you know, exist to this day. And after another 30 million years, Gondwana split into Antarctica, Africa, South America, Australia and India, which is a subcontinent, that is, it has its own continental plate. The movement of the continents continues to this day.

Presumably, our continents will collide again and form a new supercontinent, which has already been given a name - Pangea Ultima. The term Pangea Ultima and the very theory of the appearance of the mainland was coined by the American geologist Christopher Scotese, who, using various methods for calculating the movement of lithospheric plates, found that the merger could occur somewhere in 200 million years. The last Pangea, as this continent is sometimes called in Russia, will be almost entirely covered with deserts, and in the northwest and southeast there will be huge mountain ranges. .

[ ]

Since childhood, we have all become accustomed to the most popular versions of the world map, the projections of which are called the Mercator projection and the equal area projection. Gerard Mercator used such a projection back in 1569, later named after him. In modern times, such maps are used not only for the theoretical study of geography (in schools, universities), but also for various types of navigation (sea navigation, air navigation). But do not forget that what we are used to may differ from what people living on the other side of the planet are used to.

Mercator projection

Equal area projection

Projections are designed to make it easier for a person to understand the real location of the continents and parts of the world. Of course, the closest to reality is the globe, since it repeats the shape of the Earth, and in practice, the distortions on the globe seem to be the most minimal. But further we will talk not so much about the type of image of the earth's surface - projections, which have their own advantages and disadvantages, but about the very form of this surface - the continents.

As already mentioned in the flags of South America, the worldview of the peoples of different continents and, perhaps, even natural zones, geographical zones, varies greatly. This is quite likely due to the influence of various natural factors on a person, but the most interesting thing is that even the very division of the planet into continents differs depending on culture and country. So, it is customary to distinguish five different types of divisions of different detail, in which various continents are distinguished, such as: America, Afro-Eurasia, Eurasia, Australia, Antarctica, Africa, Europe, Asia, South America and North America.

The division into four continents is based on the so-called "Old" and "New" world. During the era of the "Great geographical discoveries", it was customary to unite Africa, Europe and Asia into a single ecumene, that is, a large space mastered by people, which was called Afro-Eurasia

The five-continent model evolved from the six-continent model. Differs only in the united Americas

Model with six continents with united Eurasia. Mainly used in Eastern Europe, Russia and Japan

The model with six continents with the United Americas is used mainly in France, Italy, Spain, Portugal, Romania, Latin America, Greece and some other European countries.

The seven mainland model is used in countries such as: China, India, Pakistan, the Philippines, partly in Western Europe, Australia and the UK

It is amazing how different divisions we can observe among the inhabitants of different countries. Which once again convinces us how much about th degree thoughts and actions depend on point of view.

Complicating the fission situation is the fact that the Earth was not always the same as it is today. Therefore, I would like to present a brief digression from the distant past to the present in the context of the formation of the earth's surface and tell about the largest continents of our planet throughout its existence, which are commonly called supercontinents.

Supercontinent - a large massif of the earth's crust, containing almost the entire continental crust of the planet. Thus, the supercontinent is solid, homogeneous and indivisible into parts, perhaps with the exception of some small islands.

During the existence of the Earth, seven different supercontinents have passed their life path on its surface, which we will now get to know.

Vaalbara

The first supercontinent is the most ancient, the time of existence is presumably 3.6–2.8 billion years ago, that is, from the end of the Eoarchean era to the beginning of the Neoarchean era. But its existence is only a theory.

During the existence of the supercontinent Vaalbara, there was much less land than now. The dimensions and shape of this formation are not exactly known and are mostly only hypothetical.

The lifetime of the supercontinents Vaalbara and Ur.

The name of the Vaalbara supercontinent comes from the endings of the two oldest cratons on the planet: Kaapvaal (located mainly in South Africa) and Pilbara (a region of the same name in Western Australia). On a modern photograph, the Earths are highlighted in red.

Vaalbara cratons on present-day Earth

As you can see, now there are more than eight thousand kilometers from one craton to another! But it was not always so.

Ur

The next supposed supercontinent formed about three billion years ago! It is called - Ur, from the German prefix "ur", which means "original", "primary source". Portions of this supercontinent are now parts of Australia, Africa (Madagascar) and India.

Something like this could look like Ur in Archaea

Despite the fact that Ur is called a supercontinent, its size is much smaller than modern Australia. This terrestrial formation is younger than Vaalbara by about half a billion years, but it is believed that Ur is not a continuation or successor of Vaalbara.

Kenorland

This supercontinent formed in the Neoarchean. The name was given to him in accordance with the Kenoran phase of folding. It is believed that Kenorland was located only in low latitudes.

Time of existence of Kenorland

This is what Kenorland looked like. Its parts were modern continents marked in the image, as well as cratons

Kenorland was formed from the union of several cratons (including Kaapval and Pilbara). When this supercontinent began to disintegrate, the first major glaciation on Earth formed.

Colombia (Nuna)

Columbia existed from 1.8 to 1.5 billion years ago, that is, from the beginning of the Staterian period to the end of the Calimian.

The time of existence of the supercontinent Columbia

The supercontinent is thought to have been about 12,900 kilometers north to south and about 4,800 km at its widest point from west to east.

Colombia looks like this

This supercontinent gradually began to tear apart from 1.6 billion years ago to 1.2 billion years ago.

Rodinia

The supercontinent existed in the Proterozoic, formed about 1.1 billion years ago, and broke up about 750 million years ago. The giant landmass was called Rodinia from the Russian "motherland" or "to give birth", and the ocean of that time was called Mirovia from the Russian "world" or "world".

The time of existence of Rodinia

The map of the Earth during the existence of Rodinia was already approaching the similarity of the modern one.

Rodinia, view from the South Pole

By the end of the Tonian period, the Earth began to turn into a snowball. The theory of "Earth-snowball" refers to this period.

Pannotia

This supercontinent was formed 650 million years ago and lasted until 540 million years ago. The formation of Pannotia was associated with the division of Rodinia into Proto-Gondwana and Proto-Laurasia. Since the main part of the land at that time was just near the poles, it is believed that glaciation reached its maximum exactly about 600 million years ago.

The time of existence of Pannotia

Also, during the existence of Pannotia, there were two proto-oceans - Panthalassa and the Pan-African Ocean, which surrounded the supercontinent during its closest approach.

Pannotia from the South Pole

At the end of its existence, Pannotia broke up into continents: Gondwana, Baltica, Siberia and Laurentia. Later, these continents will form the last supercontinent at the moment.

Pangea

Pangea existed at the end of the Paleozoic and the beginning of the Mesozoic, that is, 300 million years ago. At that time, the supercontinent united all modern continents into one. Many modern mountain systems originated precisely then from the collision of continents and lithospheric plates.

Time of existence of Pangea

The outlines of Pangea are the most accurate, since the existence of this supercontinent is not as ancient as the previous ones.

At the end of its existence, Pangea was divided into northern and southern continents - Laurasia and Gondwana. From Laurasia came modern Eurasia and North America, and from Gondwana - Africa, South America, India, Australia and Antarctica.

Modern Earth is the result of many complex geological and physical processes. But the form that the Earth assumed in the last periods of its existence made it possible for life to exist on Earth. The answer must be sought from here and remember that the formation of this very life is an incredibly long process stretched out over billions of years. It is hardly possible to imagine such a number of years, but one can get the closest idea of ​​this process.

Planet Earth is beautiful and amazing, and in the modern world we have even more opportunities to see this.