Rodinia. Continents and Continents Continent Rodina
During the existence of Rodinia, about 850–635 million years ago, has arrived all over the planet global ice age under the general name Snowball (the “Snowball Earth” hypothesis, common in modern science), which ended only when Rodinia split apart during a major cataclysm. The geochronological period called cryogenium, supposedly characterized by the fact that most of Rodinia was located around the south pole, and the surrounding ocean was covered with ice 2 kilometers thick. Only part of Rodinia - the future Gondwana - was located near the equator.
In the Ediacaran , 600 million years ago, when the fragments of Rodinia moved north, multicellular simple life began to develop on them, and Mirovia turned into oceans Panthalassa And Pan-African.
After Rodinia, the disintegrated continents managed to once again unite into a supercontinent Pangea[first in Pannotia] and fall apart again.
Rodinia continental civilization
200 million years after the collapse of Megagaea, the fourth overtone began, which led 1000 million years ago (at the beginning of the Late Riphean) to the emergence 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 mountains (having an Archean core), the Iranian Plateau, Tien Shan, as well as Kokshetau, Betpakdala, Ulytau, Mangyshlak and Ustyurt. At that time the continent was a high plateau with numerous volcanoes.
During its 300-million-year history, Rodinia experienced many turbulent tectonic events, among which the most ambitious was the movement of East Gondwana (East Antarctica, Western Australia and India), which broke away from North America 750 million years ago, and its rejoining 150 million years later. Rodinia from Africa.
750 million years ago, the collapse of Rodinia, which lasted for 150 - 200 million years, began with the formation of the Paleoasian, Paleoiapetus, Paleothethys and Paleopacific oceans.
In Central Kazakhstan, traces of the rift have been preserved in the form of molasse (clastic material from the sides of the rift or from the mountains) that broke off from Rodinia Kokshetau, the Northern Tien Shan and the Kazakh small hills. 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 in place of the rifts on the oceanic crust.
While Rodinia continued to disintegrate in the Vendian, in the southwest the opposite process of consolidation (collision) of the South American and African continental plates began to take place with the formation of a new continent - Western Gondwana. Western Gondwana was later joined by the island of Madagascar (which has an Archean core) and Eastern Gondwana. United Gondwana was formed in the middle of the fifth overtone, that is, by the beginning of the Cambrian, the first period of the Paleozoic era 540 million years ago.
In the late Riphean (1050-630 million years ago) and in the early Vendian (630-580 million years ago) there were two largest ice ages that bound the entire planet with ice, united by one name - Snowball. Both glacial eras are distinguished by tillite deposits, which are overlain by limestones and dolomites, which indicates a sharp climate warming that occurred. The reason for such strong glaciations remains unclear (perhaps the orbit of the Sun crossed a giant dust cloud that absorbed part of the solar heat), but a convincing hypothesis has been put forward as to 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.
The author of the chronological forecast is Travin A.A.
2.5-2.4 billion ago. The first supercontinent is Monogea.
2.2 billion ago. Disintegration of Monogea.
1.8 billion ago. A new supercontinent is formed - Megagaea.
1.4 billion ago. The collapse of Megagaia.
1 billion ago. The supercontinent Mesogea, which gradually emerged as a result of the convergence of blocks of the previously broken Megagaea
800-750 million ago. Breakup of Mesogea into Laurasia and Gondwana.
650 million ago. Breakup of Laurasia and Gondwana.
200 million ago. Once again a supercontinent (in the past - the last) - Pangea.
60 million ago. Breakup of Pangea
50 million in the future. Forecast. The Atlantic and Indian oceans will become significantly 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 .
Civilization arose 1 billion years ago - the beginning.
Civilization stopped resisting the aggressively changed environment 750 million years ago - the end.
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200 million years after the collapse of Megagaea, the fourth overtone began, which led 1000 million years ago (at the beginning of the Late Riphean) to the emergence 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 mountains (having an Archean core), the Iranian Plateau, Tien Shan, as well as Kokshetau, Betpakdala, Ulytau, Mangyshlak and Ustyurt. At that time the continent was a high plateau with numerous volcanoes.
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Zand in its 300-million-year history, Rodinia experienced many turbulent tectonic events, among which the most ambitious was the movement of East Gondwana (East Antarctica, Western Australia and India), which broke away from North America 750 million years ago, and its re-joining after 150 million years Rodinia from Africa.
7 50 million years ago, the collapse of Rodinia, which lasted for 150 - 200 million years, began with the formation of the Paleoasian, Paleoiapetus, Paleothethys and Paleopacific oceans.
INIn central Kazakhstan, traces of the rift have been preserved in the form of molasse (clastic material from the sides of the rift or from the mountains) that broke off from Rodinia Kokshetau, the Northern Tien Shan and the Kazakh small hills. 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 in place of the rifts on the oceanic crust.
INWhile in the Vendian Rodinia continued to disintegrate, in the southwest the opposite process of consolidation (collision) of the South American and African continental plates began to take place with the formation of a new continent - Western Gondwana. Western Gondwana was later joined by the island of Madagascar (which has an Archean core) and Eastern Gondwana. United Gondwana was formed in the middle of the fifth overtone, that is, by the beginning of the Cambrian, the first period of the Paleozoic era 540 million years ago.
INIn the late Riphean (1050-630 million years ago) and in the early Vendian (630-580 million years ago) there were two largest ice ages that bound the entire planet with ice, united by one name - Snowball. Both glacial eras are distinguished by tillite deposits, which are overlain by limestones and dolomites, which indicates a sharp climate warming that occurred. The reason for such strong glaciations remains unclear (perhaps the orbit of the Sun crossed a giant dust cloud that absorbed part of the solar heat), but a convincing hypothesis has been put forward as to 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.
Asecond chronological forecast Travin A.A.
2 .5-2.4 billion ago. The first supercontinent is Monogea.
2 .2 billion ago. Disintegration of Monogea.
1 .8 billion ago. A new supercontinent is being formed - Megagaia.
1 .4 billion ago. The collapse of Megagaia.
1 billion ago. The supercontinent Mesogea, which gradually emerged as a result of the convergence of blocks of the previously broken Megagaea
8 00-750 million ago. Breakup of Mesogea into Laurasia and Gondwana.
6 50 million ago. Breakup of Laurasia and Gondwana.
20 0 million ago. Once again a supercontinent (in the past - the last) - Pangea.
6 0 million ago. Breakup of Pangea
5 0 million in the future. Forecast. The Atlantic and Indian oceans will become significantly 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 .
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Continent(from Latin continents, genitive continentis) - a large mass of the earth's crust, a significant part of which is located above ocean level (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 continent, the term continent is also used.
Terminology
Mainland- a vast expanse of land washed by seas and oceans (or land, land - as opposed to water or islands). In Russian, the words continent and continent have the same meaning.
Continents from a tectonic point of view are areas of the lithosphere that have a continental structure of the earth's crust.
There are several continental models around the world (see below). In 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 a part of the world. The division into continents is made on the basis of separation by water, 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 accepted options around the world.
In geology, the continent also often includes the underwater edge of the mainland, including the islands located on it.
In English and some other languages, the word continent refers to both continents and parts of the world.
Continental models
Around 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 model of six continents with a united America (we usually call it “Parts of the World”) is popular in Spanish-speaking countries and parts of Eastern Europe including Greece with its penta-continental model (five inhabited continents).
Comparison of area and population
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Continent |
Length (km from east to west, and from south to north, along the periphery) |
Sushi share |
Population |
Population share |
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Afro-Eurasia |
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| Oceania |
- the largest and only continent on Earth, washed by four oceans: in the south - Indian, in the north - Arctic, in the west - Atlantic, in the east - Pacific. The continent is located in the Northern Hemisphere between approximately 9° W. Longitude and 169°W etc., while some of the islands of Eurasia are located in the Southern Hemisphere. Most of continental Eurasia lies in the Eastern Hemisphere, although the extreme western and eastern ends of the continent 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 entire 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, Sea of Marmara, Dardanelles, Aegean and Mediterranean Seas, Strait of Gibraltar. This division has developed historically. Naturally, there is no sharp border 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, Asian 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, the Gulf of Alaska and California, from the east by the Atlantic Ocean with the seas of Labrador, Caribbean, Gulf of St. Lawrence and Mexico, 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 passes through the Isthmus of Panama.
North America also includes numerous islands: Greenland, the Canadian Arctic Archipelago, the Aleutian Islands, Vancouver Island, the Alexandra Archipelago and others. The area of North America including the islands is 24.25 million km2, without the islands it is 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 Ocean, in 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. The Caribbean territories belong to North America. The South American countries that border the Caribbean Sea - 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 Paraná, whose total basin is 7,000,000 km2 (South America's area is 17,800,000 km2). Most of South America's lakes are 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 lake in area is Lake Maracaibo in Venezuela; it is also one of the oldest on the planet.
The tallest waterfall in the world, Angel Falls, is located in South America. The most powerful waterfall, Iguazu, is also located on the mainland.
- 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 the name given to the part of the world consisting of the continent of Africa and its adjacent islands, the largest of which is the island of Madagascar.
The African continent crosses the equator and several climate zones; its peculiarity is that it is the only continent that stretches from the northern subtropical climate zone to the southern subtropical one.
Due to the lack of constant precipitation and irrigation on the bottom of the continent - as well as glaciers or the aquifer of mountain systems - there is practically no natural regulation of climate anywhere except the coasts.
(from Latin australis - “southern”) is 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 continent 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 - Indian Ocean.
Near Australia are the large islands of New Guinea and Tasmania.
Along the northeastern coast of Australia, the well-known, largest coral reef in the world, the Great Barrier Reef, stretches for more than 2000 km.
(Greek ἀνταρκτικός - the opposite of Arctida) is a continent located in the very south of the Earth, the center of Antarctica approximately coincides with the southern geographic 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. The continent also contains about 85% of the planet's glaciers. 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 ice sheets, the average thickness of which exceeds 2,500 meters. There are 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 (approximately 2.75 billion years ago). The name comes from the Kenoran folding phase. Paleomagnetic studies indicate that Kenorland was located at low latitudes.
Nuna
Nuna (Columbia, Hudsonland) is a hypothetical supercontinent that existed between 1.8 and 1.5 Ga (maximum assembly ~1.8 Ga). Its existence was proposed by J. Rogers and M. Santosh in 2002. Nuna's existence dates back to the Paleoproterozoic era, making it presumably the oldest supercontinent. It consisted of plateau predecessors 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 continent of Colombia is based on geological and paleomagnetic data.
Rodinia
Rodinia (from Russian Rodina or from Russian to give birth) is a hypothetical supercontinent that supposedly existed in the Proterozoic - Precambrian eon. Originated about 1.1 billion years ago and disintegrated about 750 million years ago. At that time, the Earth consisted of one giant piece of land and one giant ocean, called Mirovia, also taken from the Russian language. Rodinia is often considered the oldest known supercontinent, but its position and outline are still a matter of debate. After the collapse of Rodinia, the continents managed to once again unite into the supercontinent Pangea and break up again.
Lavrussia
Laurussia (Euramerica) is a Paleozoic supercontinent formed as a result of the collision of the North American (ancient continent of Laurentia) and East European (ancient continent of Baltica) platforms during the Caledonian orogeny. The names Caledonia, “Old Red Continent”, and “Old Red Sandstone Continent” are also known. During the Permian period it connected with Pangea and became its integral part. After the collapse of Pangea, it became part of Laurasia. It disintegrated in the Paleogene.
Gondwana
Gondwanaland in paleogeography is an ancient supercontinent that arose approximately 750-530 million years ago, for a long time localized around the South Pole, which included almost all of the land now located in the southern hemisphere (Africa, South America, Antarctica, Australia), as well as tectonic blocks of Hindustan and Arabia, which have 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 period (360 million years ago) connected with the North American-Scandinavian continent into 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 emerged 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 during the Paleozoic era. The giant ocean that washed Pangea from the Silurian period of the Paleozoic to the early Mesozoic inclusive was called Panthalassa (from the ancient Greek παν - “all-” and θάλασσα “sea”). Pangea formed in the Permian period, and split at the end of the Triassic (approximately 200 - 210 million years ago) into two continents: the northern continent - Laurasia and the southern continent - Gondwana. During the formation of Pangea, mountain systems arose from more ancient continents at the sites of their collision, some of which have existed to this day, for example, the Urals or the Appalachians. These early mountains are much older than relatively young mountain systems (the Alps in Europe, the Cordillera in North America, the Andes in South America or the Himalayas in Asia). Due to erosion lasting many millions of years, the Urals and Appalachians are rolled low mountains.
Kazakhstania
Kazakhstania is a Middle Paleozoic continent that was located between Laurussia and the Siberian platform. It stretches from the Turgai trough and the Turan lowland to the Gobi and Taklamakan deserts.
Laurasia
Laurasia is a supercontinent that existed as the northern part of the fault of the protocontinent Pangea (southern Gondwana) in the late Mesozoic era. It united most of the 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.
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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, which was 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 (maritime navigation, air navigation). But we should 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 continents and parts of the world. Of course, the closest to reality is the globe, since it follows the shape of the Earth, and practically, 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 appearance of this surface - continents.
As has already been said about 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 humans, but the most interesting thing is that even the division of the planet into continents varies depending on the culture and country. Thus, it is customary to distinguish five different types of divisions of varying 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” worlds. 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 developed by people, which was called Afro-Eurasia
The five continent model evolved from the six continent model. Differs only in the united North and South Americas
Model with six continents with a united Eurasia. Used primarily 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 continent 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 great O 1st degree thoughts And actions depend on the point of view.
Complicating the division situation is the fact that the Earth was not always the same as it is today. Therefore, I would like to present a brief excursion from the distant past to the present in the context of the formation of the earth’s surface and talk about the largest continents of our planet throughout its existence, which are commonly called supercontinents.
A supercontinent is a large mass of the Earth's crust containing almost all of the planet's continental crust. Thus, the supercontinent is solid, homogeneous and indivisible, perhaps with the exception of some small islands.
During the existence of the Earth, seven different supercontinents passed their life paths on its surface, which we will now get acquainted with.
Vaalbara
The first supercontinent is the oldest, with an estimated existence of 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 size and shape of this formation are not precisely known and are mostly only hypothetical.
The lifetime of the supercontinents Vaalbara and Ur.
The name of the supercontinent Vaalbara comes from the endings of two of the oldest cratons on the planet: Kaapvaal (located mainly in South Africa) and Pilbara (the region of the same name in Western Australia). In a modern photograph, the Earths are highlighted in red.
Vaalbar cratons on modern 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 proposed 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.
This is what Ur might have looked like in Archaeum
Despite the fact that Ur is called a supercontinent, its size is significantly smaller than modern Australia. This earthly formation is younger than Vaalbara by about half a billion years, but Ur is not believed to be a continuation or successor of Vaalbara.
Kenorland
This supercontinent formed in the Neoarchean. It was named in accordance with the Kenoran folding phase. It is believed that Kenorland was located only in low latitudes.
The existence of Kenorland
This is what Kenorland looked like. Its parts were the 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 break up, the first major glaciation on Earth formed.
Colombia (Nuna)
Colombia 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 period.
The existence of the supercontinent Columbia
The supercontinent is estimated to have been about 12,900 kilometers from north to south and about 4,800 kilometers at its widest from west to east.
This is what Colombia looked like
This supercontinent gradually began to break apart from 1.6 billion years ago until 1.2 billion years ago.
Rodinia
The supercontinent existed in the Proterozoic, arose about 1.1 billion years ago, and broke up about 750 million years ago. The giant layer of land was called Rodinia from the Russian “homeland” or “to give birth”, and the ocean of that time was called Mirovia from the Russian “world” or “world”.
The existence of Rodinia
The map of the Earth during the existence of Rodinia was already approaching the semblance of the modern one.
Rodinia, view from the South Pole
Towards the end of the Tonian period, the Earth began to turn into snow. The Snowball Earth theory dates back to this period.
Pannotia
This supercontinent was formed 650 million years ago and existed 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 located near the poles, it is believed that glaciation reached its maximum exactly about 600 million years ago.
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 arose precisely then from the collision of continents and lithospheric plates.
Lifetime 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 came Africa, South America, India, Australia and Antarctica.
The modern Earth is the result of many complex geological and physical processes. But the form that the Earth took 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 stretching 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.
In early 2013, geologists found evidence that the submerged remains of an ancient microcontinent were scattered under the ocean, between Madagascar and India.
The proof was a discovery on Mauritius, a volcanic island lying about 900 km east of Madagascar. The oldest basalts there are about 8.9 million years old, says geologist Björn Jamtveit from the University of Oslo (Norway). But careful analysis of sand from two local beaches revealed about twenty zircons - crystals of zirconium silicate that are highly resistant to erosion and chemical changes. They are much older.
These zircons 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 Jamtveit and his colleagues suggest that the rocks containing these zircons originated in fragments of ancient continental crust beneath Mauritius. Apparently, relatively recent volcanic eruptions brought fragments of crust to the surface, where zircons ended up among the sand as a result of erosion.
Researchers also suspect that many fragments of that continental crust lie under the floor of the Indian Ocean. 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 remains of a landmass, which scientists propose to call Mauritia. It probably split with Madagascar when tectonic rifting and seafloor stretching caused the Indian subcontinent to move northeastward from the southern Indian Ocean. Subsequent stretching and thinning of the crust in this area led to the subsidence of fragments of Maurice, which at that time consisted of an island or archipelago with a total area of approximately three Cretes.
The scientists chose sand rather than local rocks for analysis to ensure that zircons that had been inadvertently stuck in crushing equipment from previous studies had not contaminated the fresh samples.
“We found zircon in the sand,” says University of Oslo professor Trond Torsvik, who led the study, “which is usually found in continental crust. Moreover, the zircons we found are very, very ancient.”
The closest 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 practically do not go and could hardly bring them with them. At the same time, the crystals are too large for the wind to transport them there.
Approximately 85 million years ago, leads BBC words of Professor Torsvik, 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 seismological data to get information about the geological structure of the rock on the ocean floor,” explained Professor Torsvik.
“Or you can start excavations at the bottom of the ocean, but this will cost a lot of money,” he emphasized.
Rodinia is a supercontinent believed to have formed about a billion years ago. At that time, the Earth consisted of one giant landmass and one giant ocean. Rodinia is considered the oldest known supercontinent, but its position and outline are still the subject of debate 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 creatures living at that time made such transitions more than once. While heavy iron-containing rocks sank deeper, forming a core over several hundred million years, light rocks rose to the surface to form the crust. Gravitational compression and radioactive decay further warmed the Earth's interior. Due to the increase in temperature from the surface to the center of our planet, focuses 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 flows, lithospheric plates are in constant motion, hence the emergence of volcanoes, earthquakes and continental drift. The continents are constantly moving relative to each other, but since their displacement rate is approximately 1 centimeter per year, we do not notice this movement. However, if you compare the positions of the continents over billions of years, the shifts become noticeable. The theory of continental drift was first put forward in 1912 by German geographer Alfred Wegener, when he noticed that the borders of Africa and South America were similar, like pieces of the same puzzle. Later, after studying the ocean floor, 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 there before disappeared, but now there is something that was missing in the past. Free oxygen did not immediately appear 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 ancient deposits that were clearly not subject to oxidation.
For example, river pebbles made of pyrite, which reacts well with oxygen. If this did not happen, it means that 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 exclusive source of oxygen in the atmosphere. Early in Earth's history, the oxygen produced by Archaean anaerobic microorganisms was almost immediately used up to oxidize dissolved compounds, rocks, and gases in the atmosphere. Molecular oxygen was almost non-existent; By the way, it was poisonous to most 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 free form, which led to an oxygen catastrophe. Its significance is that it has globally changed the situation of communities on the planet.
If previously 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 were previously in the minority: aerobic organisms, which previously existed only in an insignificantly small area 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 making their way to the Earth's surface. The consequence of this is a decrease in the greenhouse effect and global climate change. 1.1 billion years ago on our planet there was one giant continent - Rodinia (from Russian Rodina) and one ocean - Mirovia (from Russian world). This period is called the “Ice World” because it was very cold on our planet at that time. Rodinia is considered the oldest continent on the planet, but there are suggestions that there were other continents before it.
Rodinia broke up 750 million years ago, apparently due to rising heat currents in the Earth's mantle that bulged up parts of the supercontinent, stretching the crust and causing it to break in those places. Although living organisms existed before the Rodinia fault, it was only in the Cambrian period that animals with a mineral skeleton began to appear, which replaced soft bodies. This time is sometimes called the “Cambrian explosion”, at the same moment the next supercontinent was formed - Pangea (Greek Πανγαία - all-earth). More recently, 150-220 million years ago (and for the Earth this is a very insignificant age), Pangea broke up into Gondwana, “assembled” from modern South America, Africa, Antarctica, Australia and the islands of Hindustan, and Laurasia - the second supercontinent consisting of Eurasia and North America. Tens of millions of years later, Laurasia split into Eurasia and North America, which are known to exist to this day. And after another 30 million years, Gondwana was divided into Antarctica, Africa, South America, Australia and India, which is a subcontinent, that is, it has its own continental plate. The movement of continents continues today.
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 continent were invented by the American geologist Christopher Scotese, who, using various methods of calculating the movement of lithospheric plates, established that a 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. .
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