The Archean era dates back to the time when the Earth was formed as a planet. In geology, this is the most ancient, the earliest period of history earth's crust. The Archean era dates back to the time when the Earth was formed as a planet. In geology, this is the most ancient, the earliest period in the history of the earth's crust.
Duration: 1500 million years Duration: 1500 million years Composition of the atmosphere: chlorine, hydrogen, methane, ammonia, carbon dioxide, hydrogen sulfide, oxygen, nitrogen. The main events of the era: The emergence of the first prokaryotes. Inorganic substances of the land and atmosphere are converted into organic ones. heterotrophs appear. Soil appears. Water, and then the atmosphere is saturated with oxygen.
In the Archean era, the first living organisms arose. They were heterotrophs and used organic compounds of the "primary" broth" as food. The first inhabitants of our planet were anaerobic bacteria. The most important stage in the evolution of life on Earth is associated with the emergence of photosynthesis, which causes the separation organic world to plant and animal. The first photosynthetic organisms were prokaryotic (pre-nuclear) cyanobacteria and blue-green algae. The eukaryotic green algae that then appeared released free oxygen into the atmosphere from the ocean, which contributed to the emergence of bacteria capable of living in an oxygen environment.
The sexual process and multicellularity appeared. Haploid organisms continuously adapt to the environment, but they do not develop fundamentally new features and properties. Diploidy, which arose simultaneously with the formed nucleus, allows you to save mutations in a heterogous state and use them as a reserve. hereditary variability for further developments.
The improvement of the interaction between cells, first through contact, and then with the help of the nervous and endocrine systems, ensured the existence of a multicellular organism as a whole. Some moved to a sedentary lifestyle and turned into organisms such as sponges. From them came flatworms. Still others retained a floating lifestyle, acquired a mouth and gave rise to coelenterates.
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Prepared by:
a history teacher
MKOU Maninskaya secondary school
Bosyuk Alina Sergeevna
Purpose: to analyze the development of the Archean era
1. show the development of the Archean era from its beginning to the beginning of the Proterozoic
2. develop knowledge about archaea
3. raise interest in the history of the development of the earth
"Living bodies that exist on Earth are open, self-regulating and self-reproducing systems built from biopolymers - proteins and nucleic acids"
M. V. Volkenshtein
1912 -1992
Evolution is a process historical development organic world
Charles Darwin
1809 - 1882
This is how the surface of a primitive Earth could look like with a primitive atmosphere devoid of oxygen.
Volcanic activity played a huge role in the formation of the atmosphere.
- Cryptozoic covers about 90% of the geological time - from the moment the Earth was formed (4.6 billion years ago) to the beginning of the Paleozoic (4 billion years later).
- It is divided into two eons: Archean (4.6 billion years - 2.5 billion years ago) and Proterozoic (2.5 billion years - 0.54 billion years ago).
- Archean, Archean era (from Greek ἀρχαῖος (archios) - ancient) - a geological eon that precedes the Proterozoic
- The upper boundary of the Archean is taken to be about 2.5 billion years ago (±100 million years).
- The lower limit, which has not yet been officially recognized by the International Stratigraphic Commission, is 3.8-4 billion years ago.
Archaean division
archaeus
End of divisions (million years)
neoarchean
Mesoarchean
paleoarchaean
Eoarchean
- Approximately 3.8 billion years ago, the first reliably confirmed igneous and metamorphic mountains formed on Earth.
- Approximately 3.6 billion years ago, all the continents of the Earth united into the hypothetical supercontinent Valbara.
- 3 billion years ago, the Kola (Saami; Baltic Shield), or Transvaal ( South Africa) folding and White Sea folding (Baltic Shield), or Rhodesian (South Africa).
- Approximately 2.8 billion years ago, the first supercontinent in the history of the Earth began to break apart.
- At the very beginning of the Archean era, there was little water on Earth; instead of a single ocean, there were only scattered shallow basins.
- The water temperature reached 70-90°C.
- There was very little nitrogen in the early Archean atmosphere (10-15% of the volume of the entire Archean atmosphere).
- There was practically no oxygen at all.
- The temperature of the Archean atmosphere at greenhouse effect reached almost 120°C.
- Approximately 3.4 billion years ago, the amount of water on Earth increased significantly and the World Ocean arose, overlapping the crests of the mid-ocean ridges.
Peculiar filamentous algae have been found in siliceous rocks of the Early Archean. At many stratigraphic levels, there are the smallest rounded bodies (up to 50 m in size) of algal origin, which were previously taken for spores. They are known under the name "akritarch", or "spheromorphids".
acritarch
Throughout almost the entire Archean era, living organisms were single-celled. And only at the turn of the Archean and Proterozoic two major evolutionary events occurred: sexual process And multicellularity. The sexual process sharply increases the possibility of adaptation to environmental conditions.
Stromatolites - the oldest fossils, evidence of life on earth. They are formed by deposits of cyanobacteria (blue-green algae). Cyanobacteria absorb the energy of sunlight and form fossils, tightly clinging to each other.
"Black smoker" - the famous hydrothermal spring at the bottom Atlantic Ocean. It throws out water enriched with minerals. They fed the first bacteria.
- iron ore (ferruginous quartzites and jaspilites)
- aluminum raw materials (kyanite and sillimanite)
- manganese ores
- gold and uranium ores
- ores of copper, nickel and cobalt
- lead-zinc deposits
CONCLUSION
The Archean era originates about 4 billion years ago (the planet Earth was formed).
In the Archean era, on the border with the Proterozoic, the first cells arose - the beginning biological evolution.
Traces of an even earlier stage of development are practically disappeared.
Duration: 1500 million years Composition of the atmosphere: chlorine, hydrogen, methane, ammonia, carbon dioxide, hydrogen sulfide, oxygen, nitrogen. The main events of the era: The emergence of the first prokaryotes. Inorganic substances of the land and atmosphere are converted into organic ones. heterotrophs appear. Soil appears. Water, and then the atmosphere is saturated with oxygen.
In the Archean era, the first living organisms arose. They were heterotrophs and used organic compounds of the "primary" broth" as food. In the Archean era, the first living organisms arose. They were heterotrophs and used organic compounds of the "primary" broth" as food. The first inhabitants of our planet were anaerobic bacteria. The most important stage in the evolution of life on Earth is associated with the emergence of photosynthesis, which leads to the division of the organic world into flora and fauna. The first inhabitants of our planet were anaerobic bacteria. The most important stage in the evolution of life on Earth is associated with the emergence of photosynthesis, which leads to the division of the organic world into flora and fauna. The first photosynthetic organisms were prokaryotic (pre-nuclear) cyanobacteria and blue-green algae. The eukaryotic green algae that then appeared released free oxygen into the atmosphere from the ocean, which contributed to the emergence of bacteria capable of living in an oxygen environment. The first photosynthetic organisms were prokaryotic (pre-nuclear) cyanobacteria and blue-green algae. The eukaryotic green algae that then appeared released free oxygen into the atmosphere from the ocean, which contributed to the emergence of bacteria capable of living in an oxygen environment.
The sexual process and multicellularity appeared The sexual process and multicellularity appeared Haploid organisms continuously adapt to the environment, but they do not develop fundamentally new features and properties. Haploid organisms continuously adapt to the environment, but they do not develop fundamentally new features and properties. Diploidy, which arose simultaneously with the formed nucleus, makes it possible to preserve mutations in a heterogous state and use them as a reserve of hereditary variability for further evolutionary transformations. Diploidy, which arose simultaneously with the formed nucleus, makes it possible to preserve mutations in a heterogous state and use them as a reserve of hereditary variability for further evolutionary transformations.
The improvement of the interaction between cells, first through contact, and then with the help of the nervous and endocrine systems, ensured the existence of a multicellular organism as a whole. The improvement of the interaction between cells, first through contact, and then with the help of the nervous and endocrine systems, ensured the existence of a multicellular organism as a whole. Some moved to a sedentary lifestyle and turned into organisms such as sponges. From them came flatworms. Some moved to a sedentary lifestyle and turned into organisms such as sponges. From them came flatworms. Still others retained a floating lifestyle, acquired a mouth and gave rise to coelenterates. Still others retained a floating lifestyle, acquired a mouth and gave rise to coelenterates.
Conclusions: Life originated on Earth from abiogenically synthesized organic molecules. Life originated on Earth from abiogenically synthesized organic molecules. In the Archean era, on the border with the Proterozoic, the emergence of the first cells marked the beginning of biological evolution. In the Archean era, on the border with the Proterozoic, the emergence of the first cells marked the beginning of biological evolution.
life in the Archean era MOU "Poksheng Basic School No. 21" Completed by: Amosov Anton Teacher: Bogdanova L.V.
Duration Archean, Archean era - geological eon. The upper boundary of the Archean is taken to be about 2.5 billion years ago (±100 million years). Beyond the lower boundary, approximately - 3.8-4 billion years ago. The duration of the Archean is approximately 1.5 billion years.
Archean Era Periods: Eoarchean Paleoarchean Mesoarchean Neoarchean
Climate and environment Active volcanic activity. Anaerobic (oxygen-free) living conditions in a shallow ancient sea. Development of an oxygen-containing atmosphere.
Development of the organic world In the Archean era, the first living organisms arose. They were heterotrophs and used organic compounds of the "primary" broth" as food. The first inhabitants of our planet were anaerobic bacteria. The most important stage in the evolution of life on Earth is associated with the emergence of photosynthesis, which leads to the division of the organic world into flora and fauna. The first photosynthetic organisms were prokaryotic (pre-nuclear) cyanobacteria and blue-green algae. The eukaryotic green algae that then appeared released free oxygen into the atmosphere from the ocean, which contributed to the emergence of bacteria capable of living in an oxygen environment.
Flora and fauna In the Archean deposits there is no skeletal fauna, which serves as the basis for constructing the Phanerozoic stratigraphic scale, nevertheless, there are quite a lot of various traces of organic life here. Animal world archaea is much poorer than vegetable. Separate indications of the presence of animal remains in the Archean rocks refer to objects that, apparently, are of inorganic origin or are leaching products of stromatolites
Conclusion 1 Life originated on Earth from organic molecules synthesized abiogenically. 2. In the Archean era, on the border with the Proterozoic, the emergence of the first cells marked the beginning of biological evolution.
Eoarchean Eoarchean - the lower period of the Archean era, covering the time interval from 4 to 3.6 billion years ago. Eoarchean is remarkable in that it is the time of the formation of the hydrosphere and the discovery of the alleged remains of the first prokaryotes, stromatolites and ancient rocks. At the very beginning of the Archean era, there was little water on Earth; instead of a single ocean, there were only scattered shallow basins. The water temperature reached 70-90°C, which could only be observed if the Earth had a dense carbon dioxide atmosphere at that time.
Paleoarchean Paleoarchean - the period following the Eorcheian, is the time of the formation of the first supercontinent in the history of the Earth - Vaalbara and a single World Ocean, which overlapped the crests of the mid-ocean ridges. As a result, the hydration of the basaltic oceanic crust noticeably increased, and the growth rate of CO2 partial pressure in the Late Archean atmosphere somewhat decreased. The first reliable remains of living organisms (bacteria) and traces of their vital activity also belong to this time. The duration of the Paleoarchean is 400 million years.
Mesoarchean The Mesoarchean lasted from 3.2 to 2.8 billion years ago. The period of the split of Vaalbara and the wide distribution of fossils of ancient life forms is interesting here.
Neoarchean Neoarchean - the last period of the Archean era, which ended 2.5 billion years ago, is the time of formation of the main mass of the continental crust, which indicates the exceptional antiquity of the Earth's continents.
Archean era- this is the first stage in the development of life on earth, an exciting time interval of 1.5 billion years. It originates 4 billion years ago. During the Archean era, the flora and fauna of the planet begin to emerge, from here the history of dinosaurs, mammals and humans begins. The first deposits of the natural wealth of nature appear. There were no mountain heights and the oceans, there was not enough oxygen. The atmosphere was mixed with the hydrosphere into a single whole - this prevented the sun's rays from reaching the earth.
The Archean era in translation from ancient Greek means "ancient". This era is divided into 4 periods - Eoarchean, Paleoarchean, Mesoarchean and Neoarchean.
The first period of the Archean era lasted approximately 400 million years. This period is characterized by increased meteor showers, the formation of volcanic craters and the earth's crust. Active formation of the hydrosphere begins, salty reservoirs with hot water isolated from each other appear. The atmosphere is dominated by carbon dioxide, the air temperature reaches 120 °C. The first living organisms appear - cyanobacteria, which begin to produce oxygen through photosynthesis. Vaalbara, the main terrestrial continent, is being formed.
paleoarchaean
The next period of the Archean era captures a period of time of 200 million years. The Earth's magnetic field is enhanced by increasing the hardness of the Earth's core. This favorably affects the conditions of life and development of the simplest microorganisms. Days last about 15 hours. The oceans are being formed. Changes in submarine ridges lead to a slow increase in the volume of water and a decrease in the amount of carbon dioxide in the atmosphere. The formation of the first terrestrial continent continues. Mountain ranges do not yet exist. Instead, active volcanoes rise above the ground.
Mesoarchean
The third period of the Archean era lasted 400 million years. At this time, the main continent split into 2 parts. As a result of a sharp cooling of the planet, in which constant volcanic processes are to blame, the Pongol glacial formation. During this period, the number of cyanobacteria begins to actively grow. Chemolithotrophic organisms develop that do not need oxygen and sunlight. Vaalbar is fully formed. Its size is approximately equal to the size of modern Madagascar. The formation of the Ur continent begins. Large islands slowly begin to form from volcanoes. The atmosphere is still dominated by carbon dioxide. The air temperature remains high.
The last period of the Archean era ended 2.5 billion years ago. At this stage, the formation of the earth's crust is completed, the level of oxygen in the atmosphere increases. The mainland of Ur becomes the basis of Kenorland. Most of the planet is occupied by volcanoes. Their activity leads to advanced education mineral. Gold, silver, granites, diorites and other equally important natural resources were formed during the Neoarchean period. IN last centuries of the Archean era the first multicellular organisms appear, which later divided into terrestrial and marine inhabitants. Bacteria begin the development of the sexual process of reproduction. Haploid microorganisms have one chromosome set. They are constantly adapting to changes in their environment, but they do not have other properties. The sexual process allowed adaptation to life with changes in the set of chromosomes. This made it possible for the further evolution of living organisms.
Flora and fauna of the Archean era
The flora of this era cannot boast of diversity. The only plant species are unicellular filamentous algae - spheromorphids - the habitat of bacteria. When these algae form in colonies, they can be seen without special instruments. They can go free swimming or attach themselves to the surface of something. In the future, algae will form a new form of life - lichens.
During the Archean era, the first prokaryotes - unicellular organisms that do not have a nucleus. With the help of photosynthesis, prokaryotes produce oxygen and create favorable conditions for the emergence of new forms of life. Prokaryotes are divided into two domains - bacteria and archaea.
Archaea
It has now been established that they have features that distinguish them from other living organisms. Therefore, the classification that combines them with bacteria in one group is considered outdated. Outwardly, archaea are similar to bacteria, but some have unusual shapes. These organisms can absorb sunlight, as well as carbon. They can exist in the most unsuitable conditions for life. One type of archaea is food for marine life. Several species have been found in the human intestine. They take part in the processes of digestion. Other species are used to clean sewage ditches and ditches.
There is an unconfirmed theory that during the Archean era, the emergence and development of eukaryotes - microorganisms of the kingdom of fungi, similar to yeast fungi.
The fact that life on earth originated during the Archean era is evidenced by the found fossilized stromalites - waste products of cyanobacteria. The first stromatolites were discovered in Canada, Siberia, Australia and Africa. Scientists have proven that it was bacteria that had a huge impact on the formation of aragonite crystals, which is found in mollusk shells and is part of corals. Thanks to cyanobacteria, deposits of carbonate and siliceous formations arose. Colonies of ancient bacteria look like mold. They were located in the area of volcanoes, and at the bottom of lakes, and in coastal areas.
Archean climate
Scientists have not yet been able to find out about climatic zones of this period. The existence of zones of different climates in the Archean era can be judged by ancient glacial deposits - tillites. The remains of glaciations are now found in America, Africa, and Siberia. It is not yet possible to determine their true dimensions. Most likely, glacial deposits covered only the mountain peaks, because the vast continents during the Archean era had not yet been formed. The existence of a warm climate in some areas of the planet is indicated by the development of flora in the oceans.
Hydrosphere and Atmosphere of the Archean Era
In the early period, there was little water on earth. The water temperature during the Archean era reached 90°C. This indicates the saturation of the atmosphere with carbon dioxide. There was very little nitrogen in it, there was almost no oxygen in the early stages, the remaining gases are quickly destroyed under the influence of sunlight. The temperature of the atmosphere reaches 120 degrees. If nitrogen prevailed in the atmosphere, then the temperature would not be lower than 140 degrees.
In the late period, after the formation of the world ocean, the level of carbon dioxide began to decrease markedly. The water and air temperature also dropped. And the amount of oxygen increased. Thus, the planet gradually became habitable for various organisms.
Minerals of Archaea
It is in the Archean era that the greatest formation of minerals occurs. This is facilitated by the active activity of volcanoes. Colossal deposits of iron, gold, uranium and manganese ores, aluminum, lead and zinc, copper, nickel and cobalt ores were laid by this era of the life of the earth. In the territory Russian Federation Archean deposits have been found in the Urals and Siberia.
In details periods of the archean era will be discussed in the next lectures.
