CorrectMyText Kullanıcılar
İngilizce dil
Kullanıcıdan düzeltme metni Adri1
Hello everybody!
I'm a 20 years old french boy and I study Biology in France.
A few weeks ago, I wrote a text for a geology "homework" and I decided to write it like a popular science article.
My teacher was impressed (i get a 20/20) and he asked me to rewrite it, but in English this time!
I'm good in English but this time, it's a little bit too hard for me and I need somebody with a strong English skill (Someone for whom it is the mother tongue or a English teacher... )
I know that this is a very long text but I would understand if you just correct a part of it
Lot of thanks!!
Abstract
Through this quick essay, we'll try to answer, by an accessible, pleasant and comprehensible way and in the style of a popular article, about the question of the appearance of the terrestrial atmosphere by the event we usually name the Great Oxygenation, its consequences and its link with the ecologic crisis which occurred 2. 4 billion years ago.
Oxygen is one of the most important matter (substance? ) on Earth and essential for most of the organism which live on. No surprise on this side...
Nowadays, oxygen is in big proportion of the air we breath (usually 21%), but the primitive Earth atmosphere was different in many ways. How oxygen did appear? What were the consequences? How can we date its appearance? Modern science now allows to reveal these process, as well biological as geological, without which the world as we know it, would not exist.
HOW WE’VE DATED THE INVISIBLE
Nowadays, fossils and rocks datations are became common (among others, thanks to the radiometric datation), what about matters wich leave nothing behind them? How to date the appearance of a gas like dioxygen on Earth? A question that seems to be insolvable but however, by being based on indirect hints, that is to say some visible or measurable consequences of the O2 presence, we can estimate its onset.
THE SULPHUR ISOTOPES
There are four stable sulphur atom isotopes (four variants with different nucleic constitution). By studying some sedimentary rocks, a sulphur isotopes repartition captured within them, can be established (called isotope fractionning).
Today, biologic phenomenons lead an isotopic variety but this experience reveals a poor isotopic rate in more than 2. 4 billion years rocks. It proves that non-fractionning reactions took place before 2. 4 billion years.
But this kind of reactions are only known under heavy UV radiation, which existed on an Earth without ozone layer.
The increasing isotopic rate in rocks from 2 billion years betray an attenuation of UV radiation induced by the presence of an ozone layer. Ozone being go hand in hand with the dioxygen release 2 billion years ago.
THE URANITE ORES
Uranite is a rock derived from uranium whose deposits had formed 3. 4 billion years ago. In anoxic environment, these rocks are insoluble in water but in the opposite case, the minerals can dissolve and being carried away by soils leaching (rainwater runoff). So, we notice a disappearance of uranite after 2 billion years, which proves an atmosphere oxydation took place.
THE BANDED IRON FORMATIONS
In the primitive Archean oceans (till -2. 5 billion years) the hydrothermal springs were the main sources of iron. Initially reducer (without oxygen), the marine environment allowed the presence of dissolved iron Fe2+. When the environment became oxidant (presence of oxygen), iron compounds were able to be oxidised into insoluble materials (magnetite Fe3O4, hematite Fe2O3). The appearance of red banded rocks from -2. 4 billion years betray the compounds deposition process after their oxidation. The continental oxidised iron rocks deposits are newer (2-1. 5 billion years) and reveal that the aerial environment would have been oxidised after the oceans.
LIFE, INSTIGATOR OF THE
GREAT OXYGENATION EVENT...
Let's make a quick summary. 3. 85 billion years ago, while the Earth cool down barely from the late meteoric bombing, the hydrosphere timidly sets up by water vapors precipitation. The primitive atmosphere too start to make up from the degassing of earth's mantle induced by a strong volcanism. Hydrogen, nitrogen, carbon dioxide (CO2), ammonia (NH2) and methane (CH4): these are the components of this new air. Not a breath of dioxygen!
THE APPEARANCE OF LIFE AND PHOTOSYNTHESIS
As soon as it could, life has made its way through this anoxic world, some 3. 8 billion years ago. The first organisms simply collect carbon by absorbing the few nutrients within their range. Then has appeared - we date this at -2. 7 billion years - a evolutionary character of a crucial significiance and of an unprecedented kind. In shallow waters, protected from deadly UV rays, a bacterium gain the capacity to create organic matter from CO2 dissolved in the water and light, both abundant: the cyanobacteria is born. Based on this obvious evolutionary advantage, this new life form grow and invade marine environment. In this way, little by little, a new substance at that time, a waste from the cyanobacterian photosynthesis, start to accumulate.
THE GREAT OXYGENATION EVENT
This waste is obviously the dioxygen. But is it going to spread straight in th atmosphere? Well, no because, as said before, cyanobacteria are marine organisms and as such, their wastes are emitted in water first. The freed oxygen is going to bind with many compounds in reduced form in the water (mainly from volcanism). The most significant among them is the iron, which once oxidised, precipitate to the seafloor and will form, at the cost of thousands of years, banded rocks (see previous page). But when there is a lack of matter to oxidize, then the dioxygen concentrate and, by simple molecular diffusion, is freed in the atmosphere. 2. 4 billions years ago, the dioxygene finally reach a content of... 0. 1%. Few, very few but enough to cause a multiple scales global disruption. Also sufficient, to name this event "the oxygen catastrophy" or "the great oxygenation event" because it will have an effect as well on the climat and the terrestrial atmosphere features as on the existing biologic fauna (anaerobic organisms) of Paleozoic (see next page).
... WITH A LITTLE HELP FROM GEOLOGY
THE AERIAL VOLCANISM TO THE RESCUE OF DIOXYGEN
More recent studies suggest that the cyanobacterian theory wouldn't be self-sufficient. Indeed, the freed dioxygen wouldn't have been in sufficient proportion compared to the huge amount of oxidizable matters. Some geological explanations can support, not to replace the biologic theory but in order to complete it. 2. 7 billion years ago, a period of strong geologic activity lead to which would surely be the most intense epsiode of continental crust creation. From a nearly all water-covered Earth, we now see continents and reliefs. An aerial volcanism can now exist with the release of sulphure-rich gases in the atmosphere. The sulphure massively added to atmosphere cause the solubilisation of sulphates ions (found in the air too) in the water.
THE SULPHURE BIOGEOCHEMICAL CYCLE
As a new chemical species in the oceans, the sulphates quickly find their usefulness by doing sulphate-reducing reactions, in particular allowing to stabilise the sea iron into iron sulphide. Quickly, the iron from hydrothermal vents is fully consummed and the oceans are washed from it. We know what happen next, the dioxygen is freed from its liquid constraint and reach the atmosphere. The great oxygenation event thus present biologic causes made easier by geological factors.
IS THE LIFE RESPONSIBLE FOR ITS OWN DISAPPEARANCE?
DIOXYGEN AND MASS EXCTINCTION
By gaining the gift of photosynthesis, the cyanobacteria is an exception among the kingdom of life which dominated. Don't forget that the dioxygen they massively expel is a waste which is toxic for others life forms. Indeed, the dioxygen is a novelty for all of the then anaerobic organisms (pour les organismes anaérobies d'alors), that is to say none of them know how to use it (by "knowing", we here mean to have the biologic structure and the tools to use it). On the other hand, by the same way that the dioxygen binds with whatever could be oxidised, it attacks the organic matter (by oxiding it). We easily understand why the fast and massive release of dioxygen in the marine and aerial environment catched living beings off-guard and that the ones unabled to fast adapt passed away.
DIOXYGEN AND ICE AGE
When the dioxygen rate has been sufficiently high in the atmosphere, it started to react with the methane already in there. As the outcome of this reaction, the methane was fully consumed and replaced by carbon dioxide. The latter having a fewer global warming potential than the methane, it occurs a decrease of the greenhouse effect and, ultimately, a decrease of the global temperature. It marks the beginning of an ice age that will last until -2. 1 billion years, we talk about the huronian glaciation and the expression "Snowball Earth" is often used to illustrate the terrestrial surface entirely frozen.
DIOXYGEN AND OZONE LAYER
The arrival of dioxygen on Earth didn't have only bad consequences, it has indeed allowed the formation of the ozone layer, the same which will provide an UV rays protection and will allows living organisms to thrive.
LETTERS TO THE EDITOR
BEYOND THE ONES EXPLAINED IN THE ARTICLE, WHAT WERE BEEN THE CONSEQUENCES OF THIS EVENT?
YOU are a convincing example of a consequence of the great oxygenation event. Once the huronian glaciation ended, many organisms started to use the dioxygen, especially by the aerobic respiration. The efficiency of this reaction to regenerate the energy (up to 15 times more than anaerobic respiration) combined to the ideal conditions (ozone layer, high amount of nutrients brought by the thaw) have favored the appearance and evolution of more and more complex multicellular life... and here you are!
IS THERE ANY LUCRATIVE APPLICATION TO GET FROM THESE KNOWLEDGES?
Unfortunately (or not... ), science sometimes only brings from its conclusions the pure satisfaction of knowing. Beyond the great sceintific interest of this subject (appearance of complexe life, of ozone layer, understanding of huronian glaciation and their linkage with geologic observations), it's right to say that there is no lucrative prospect. In the case of banded iron deposits, mankind didn't wait to know about its origins to start to exploit it...
WHAT ABOUT EXOBIOLOGY AND EXOGEOLOGY?
In a first time, the main goal is always to understand the biological and/or geological process binded to Earth. But, it's true that on a longer term and when we try to extrapolate the earth theories, it's completely appropriate to use such knowledges in exobiology and exogeology domains. Because these process are closely linked with the appearance of life, its evolution and the establishment of favorable living conditions, they can be searched on other solar-system planets (and their satellites) or on exoplanets we can now analyse. What worked on Earth, may have been occured somewhere else (and vice-versa) and that would be a solid argument for claiming the existence of a present or past extraterrestrial life. We are today attending to the birth of new branches of science, an "exo-science" unknown to Earth!
dil: İngilizce
Dil bilgisi: Anadili, Yeterlilik
I'm a 20 years old french boy and I study Biology in France.
A few weeks ago, I wrote a text for a geology "homework" and I decided to write it like a popular science article.
My teacher was impressed (i get a 20/20) and he asked me to rewrite it, but in English this time!
I'm good in English but this time, it's a little bit too hard for me and I need somebody with a strong English skill (Someone for whom it is the mother tongue or a English teacher... )
I know that this is a very long text but I would understand if you just correct a part of it
Lot of thanks!!
Abstract
Through this quick essay, we'll try to answer, by an accessible, pleasant and comprehensible way and in the style of a popular article, about the question of the appearance of the terrestrial atmosphere by the event we usually name the Great Oxygenation, its consequences and its link with the ecologic crisis which occurred 2. 4 billion years ago.
Oxygen is one of the most important matter (substance? ) on Earth and essential for most of the organism which live on. No surprise on this side...
Nowadays, oxygen is in big proportion of the air we breath (usually 21%), but the primitive Earth atmosphere was different in many ways. How oxygen did appear? What were the consequences? How can we date its appearance? Modern science now allows to reveal these process, as well biological as geological, without which the world as we know it, would not exist.
HOW WE’VE DATED THE INVISIBLE
Nowadays, fossils and rocks datations are became common (among others, thanks to the radiometric datation), what about matters wich leave nothing behind them? How to date the appearance of a gas like dioxygen on Earth? A question that seems to be insolvable but however, by being based on indirect hints, that is to say some visible or measurable consequences of the O2 presence, we can estimate its onset.
THE SULPHUR ISOTOPES
There are four stable sulphur atom isotopes (four variants with different nucleic constitution). By studying some sedimentary rocks, a sulphur isotopes repartition captured within them, can be established (called isotope fractionning).
Today, biologic phenomenons lead an isotopic variety but this experience reveals a poor isotopic rate in more than 2. 4 billion years rocks. It proves that non-fractionning reactions took place before 2. 4 billion years.
But this kind of reactions are only known under heavy UV radiation, which existed on an Earth without ozone layer.
The increasing isotopic rate in rocks from 2 billion years betray an attenuation of UV radiation induced by the presence of an ozone layer. Ozone being go hand in hand with the dioxygen release 2 billion years ago.
THE URANITE ORES
Uranite is a rock derived from uranium whose deposits had formed 3. 4 billion years ago. In anoxic environment, these rocks are insoluble in water but in the opposite case, the minerals can dissolve and being carried away by soils leaching (rainwater runoff). So, we notice a disappearance of uranite after 2 billion years, which proves an atmosphere oxydation took place.
THE BANDED IRON FORMATIONS
In the primitive Archean oceans (till -2. 5 billion years) the hydrothermal springs were the main sources of iron. Initially reducer (without oxygen), the marine environment allowed the presence of dissolved iron Fe2+. When the environment became oxidant (presence of oxygen), iron compounds were able to be oxidised into insoluble materials (magnetite Fe3O4, hematite Fe2O3). The appearance of red banded rocks from -2. 4 billion years betray the compounds deposition process after their oxidation. The continental oxidised iron rocks deposits are newer (2-1. 5 billion years) and reveal that the aerial environment would have been oxidised after the oceans.
LIFE, INSTIGATOR OF THE
GREAT OXYGENATION EVENT...
Let's make a quick summary. 3. 85 billion years ago, while the Earth cool down barely from the late meteoric bombing, the hydrosphere timidly sets up by water vapors precipitation. The primitive atmosphere too start to make up from the degassing of earth's mantle induced by a strong volcanism. Hydrogen, nitrogen, carbon dioxide (CO2), ammonia (NH2) and methane (CH4): these are the components of this new air. Not a breath of dioxygen!
THE APPEARANCE OF LIFE AND PHOTOSYNTHESIS
As soon as it could, life has made its way through this anoxic world, some 3. 8 billion years ago. The first organisms simply collect carbon by absorbing the few nutrients within their range. Then has appeared - we date this at -2. 7 billion years - a evolutionary character of a crucial significiance and of an unprecedented kind. In shallow waters, protected from deadly UV rays, a bacterium gain the capacity to create organic matter from CO2 dissolved in the water and light, both abundant: the cyanobacteria is born. Based on this obvious evolutionary advantage, this new life form grow and invade marine environment. In this way, little by little, a new substance at that time, a waste from the cyanobacterian photosynthesis, start to accumulate.
THE GREAT OXYGENATION EVENT
This waste is obviously the dioxygen. But is it going to spread straight in th atmosphere? Well, no because, as said before, cyanobacteria are marine organisms and as such, their wastes are emitted in water first. The freed oxygen is going to bind with many compounds in reduced form in the water (mainly from volcanism). The most significant among them is the iron, which once oxidised, precipitate to the seafloor and will form, at the cost of thousands of years, banded rocks (see previous page). But when there is a lack of matter to oxidize, then the dioxygen concentrate and, by simple molecular diffusion, is freed in the atmosphere. 2. 4 billions years ago, the dioxygene finally reach a content of... 0. 1%. Few, very few but enough to cause a multiple scales global disruption. Also sufficient, to name this event "the oxygen catastrophy" or "the great oxygenation event" because it will have an effect as well on the climat and the terrestrial atmosphere features as on the existing biologic fauna (anaerobic organisms) of Paleozoic (see next page).
... WITH A LITTLE HELP FROM GEOLOGY
THE AERIAL VOLCANISM TO THE RESCUE OF DIOXYGEN
More recent studies suggest that the cyanobacterian theory wouldn't be self-sufficient. Indeed, the freed dioxygen wouldn't have been in sufficient proportion compared to the huge amount of oxidizable matters. Some geological explanations can support, not to replace the biologic theory but in order to complete it. 2. 7 billion years ago, a period of strong geologic activity lead to which would surely be the most intense epsiode of continental crust creation. From a nearly all water-covered Earth, we now see continents and reliefs. An aerial volcanism can now exist with the release of sulphure-rich gases in the atmosphere. The sulphure massively added to atmosphere cause the solubilisation of sulphates ions (found in the air too) in the water.
THE SULPHURE BIOGEOCHEMICAL CYCLE
As a new chemical species in the oceans, the sulphates quickly find their usefulness by doing sulphate-reducing reactions, in particular allowing to stabilise the sea iron into iron sulphide. Quickly, the iron from hydrothermal vents is fully consummed and the oceans are washed from it. We know what happen next, the dioxygen is freed from its liquid constraint and reach the atmosphere. The great oxygenation event thus present biologic causes made easier by geological factors.
IS THE LIFE RESPONSIBLE FOR ITS OWN DISAPPEARANCE?
DIOXYGEN AND MASS EXCTINCTION
By gaining the gift of photosynthesis, the cyanobacteria is an exception among the kingdom of life which dominated. Don't forget that the dioxygen they massively expel is a waste which is toxic for others life forms. Indeed, the dioxygen is a novelty for all of the then anaerobic organisms (pour les organismes anaérobies d'alors), that is to say none of them know how to use it (by "knowing", we here mean to have the biologic structure and the tools to use it). On the other hand, by the same way that the dioxygen binds with whatever could be oxidised, it attacks the organic matter (by oxiding it). We easily understand why the fast and massive release of dioxygen in the marine and aerial environment catched living beings off-guard and that the ones unabled to fast adapt passed away.
DIOXYGEN AND ICE AGE
When the dioxygen rate has been sufficiently high in the atmosphere, it started to react with the methane already in there. As the outcome of this reaction, the methane was fully consumed and replaced by carbon dioxide. The latter having a fewer global warming potential than the methane, it occurs a decrease of the greenhouse effect and, ultimately, a decrease of the global temperature. It marks the beginning of an ice age that will last until -2. 1 billion years, we talk about the huronian glaciation and the expression "Snowball Earth" is often used to illustrate the terrestrial surface entirely frozen.
DIOXYGEN AND OZONE LAYER
The arrival of dioxygen on Earth didn't have only bad consequences, it has indeed allowed the formation of the ozone layer, the same which will provide an UV rays protection and will allows living organisms to thrive.
LETTERS TO THE EDITOR
BEYOND THE ONES EXPLAINED IN THE ARTICLE, WHAT WERE BEEN THE CONSEQUENCES OF THIS EVENT?
YOU are a convincing example of a consequence of the great oxygenation event. Once the huronian glaciation ended, many organisms started to use the dioxygen, especially by the aerobic respiration. The efficiency of this reaction to regenerate the energy (up to 15 times more than anaerobic respiration) combined to the ideal conditions (ozone layer, high amount of nutrients brought by the thaw) have favored the appearance and evolution of more and more complex multicellular life... and here you are!
IS THERE ANY LUCRATIVE APPLICATION TO GET FROM THESE KNOWLEDGES?
Unfortunately (or not... ), science sometimes only brings from its conclusions the pure satisfaction of knowing. Beyond the great sceintific interest of this subject (appearance of complexe life, of ozone layer, understanding of huronian glaciation and their linkage with geologic observations), it's right to say that there is no lucrative prospect. In the case of banded iron deposits, mankind didn't wait to know about its origins to start to exploit it...
WHAT ABOUT EXOBIOLOGY AND EXOGEOLOGY?
In a first time, the main goal is always to understand the biological and/or geological process binded to Earth. But, it's true that on a longer term and when we try to extrapolate the earth theories, it's completely appropriate to use such knowledges in exobiology and exogeology domains. Because these process are closely linked with the appearance of life, its evolution and the establishment of favorable living conditions, they can be searched on other solar-system planets (and their satellites) or on exoplanets we can now analyse. What worked on Earth, may have been occured somewhere else (and vice-versa) and that would be a solid argument for claiming the existence of a present or past extraterrestrial life. We are today attending to the birth of new branches of science, an "exo-science" unknown to Earth!
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Aşağıdaki seviyelerden birinde İngilizce'ye belirttiyseniz bu metni düzeltebilirsiniz: Anadili, Yeterlilik
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