Oxygen formation in Earth water

[cookiemonster13]

I always wondered why they say water and photons created the first microbes which later evolved and produced oxygen which filled our oceans and atmosphere. So how could have water existed without oxygen? I tried to look up and came up with different explanations, but it doesn't make sense.

 

[Evo]

I always wondered why they say water and photons created the first microbes which later evolved and produced oxygen which filled our oceans and atmosphere. So how could have water existed without oxygen? I tried to look up and came up with different explanations, but it doesn't make sense.

You need to read about stromatolites.

from the link below

Bacteria, including the photosynthetic cyanobacteria, were the only form of life on Earth for the first 2 billion years that life existed on Earth. Stromatolites are layered mounds, columns, and sheet-like sedimentary rocks. They were originally formed by the growth of layer upon layer of cyanobacteria, a single-celled photosynthesizing microbe that lives today in a wide range of environments ranging from the shallow shelf to lakes, rivers, and even soils. Cyanobacteria are prokaryotic cells (the simplest form of modern carbon-based life) in that they lack a DNA-packaging nucleus.

Although simple, cyanobacteria were ultimately responsible for one of the most important "global changes" that the Earth has undergone. Being photosynthetic, cyanobacteria produce oxygen as a by-product. Photosynthesis is the only major source of free oxygen gas in the atmosphere. As stromatolites became more common 2.5 billion years ago, they gradually changed the Earth's atmosphere from a carbon dioxide-rich mixture to the present-day oxygen-rich atmosphere. This major change paved the way for the next evolutionary step, the appearance of life based on the eukaryotic cell (cell with a nucleus).

http://www.indiana.edu/~geol105b/images/gaia_chapter_10/stromatolites.htm

 

[cookiemonster13]

Totally agree with that. But they needed water to survive. Hence H2O, then how? o.o
idk if I am wrong here..

 

[Evo]

Totally agree with that. But they needed water to survive. Hence H2O, then how? o.o
idk if I am wrong here..

That appears to be something that is unknown, there are some theories. I will do more searching for you later today, I was unable to come up with much earlier, just the usual theories, comets, asteroids... That may be the best we have at this time.

http://www.livescience.com/33391-where-did-water-come-from.html

 

[davenn]

I always wondered why they say water and photons created the first microbes which later evolved and produced oxygen which filled our oceans and atmosphere. So how could have water existed without oxygen?

I think you will find that the microbes just added the oxygen content to the atmosphere as stated in that link @Evo gave.
There's no reason to suggest that the microbes existed BEFORE the oceans, which is what you are suggesting

So do you have any links to back up your "they say" claim ?Dave

 

[cookiemonster13]

That appears to be something that is unknown, there are some theories. I will do more searching for you later today, I was unable to come up with much earlier, just the usual theories, comets, asteroids... That may be the best we have at this time.

http://www.livescience.com/33391-where-did-water-come-from.html

Thanks.. :)

 

[cookiemonster13]

I think you will find that the microbes just added the oxygen content to the atmosphere as stated in that link @Evo gave.
There's no reason to suggest that the microbes existed BEFORE the oceans, which is what you are suggesting

So do you have any links to back up your "they say" claim ?Dave

Hi sup? I don't really remember. I watched some documentaries and googled up some stuffs. I'll try to look for that and send it to you.

 

[davenn]

no prob's

it's just a really good idea to give links (reliable ones) to claims
you will find that "they say" doesn't really cut the mustard on the forumand btw ... welcome to PFDave

 

[cookiemonster13]

th

no prob's

it's just a really good idea to give links ( reliable ones) to claims
you will find that "they say" doesn't really cut the mustard on the forumand btw ... welcome to PFDave

thanks bro

 

[CapnGranite]

The role of stromatolites in the oxygenation of Earth is a "yes, but..." story. I have a couple hundred papers that show the complexity of the problem. I was, and am, more concerned with astrobiology and the origin of life and my experience in molecular paleontology is with a Jurassic and younger earth. I'll post a few of the papers now. The first has a nice chart showing some major biogeochemical changes in the early earth. Significant is that there is a huge burst in C-13 associated with stromatolites.

Global Biogeochemical Changes at Both Ends of the Proterozoic: Insights from Phosphorites
ASTROBIOLOGY Volume 10, Number 2, 2010 a Mary Ann Liebert, Inc. DOI: 10.1089=ast.2009.0360

Availability of O2 and H2O2 on Pre-Photosynthetic Earth
ASTROBIOLOGY Volume 11, Number 4, 2011 a Mary Ann Liebert, Inc. DOI: 10.1089/ast.2010.0572

Stromatolites in the *3400 Ma Strelley Pool Formation, Western Australia: Examining Biogenicity
from the Macro- to the Nano-Scale
ASTROBIOLOGY Volume 10, Number 4, 2010 a Mary Ann Liebert, Inc. DOI: 10.1089=ast.2009.0423

The case for a Neoproterozoic Oxygenation Event: Geochemical evidence and biological consequences
http://www.geosociety.org/gsatoday/archive/21/3/article/i105

The Proterozoic Record of Eukaryotes
http://paleobiol.geoscienceworld.org/content/41/4/610.abstract?ijkey=171be971757c6becfb61c21509908b70a1215f50&keytype2=tf_ipsecsha

Tropical laterites, life on land, and the history of atmospheric oxygen in the Paleoproterozoic
http://geology.gsapubs.org/content/30/6/491.full.pdf

Were kinetics of Archean calcium carbonate precipitation related to oxygen concentration?
http://geology.gsapubs.org/content/24/2/119.full.pdf+html

Oxygen in the Precambrian atmosphere: An evaluation of the geological evidence
http://geology.gsapubs.org/content/10/3/141.full.pdf+html

This is a decent start, I think.

 

[CapnGranite]

https://arxiv.org/pdf/1011.2710v1.pdf
Formation of early water oceans on rocky planets

Lindy E-T, the author of that paper, showed that enough water could be carried in the primordial dust and survived the accretionary phases such that the Earth had enough water in its earliest stages to account for the water that is now here. Asteroids, meteorites and comets aren't needed to account for the original ocean volume.
Occam's origin of the Moon Nature Geoscience 6, 996–998 (2013) doi:10.1038/ngeo2026
"Following almost three decades of some certainty over how the Moon was formed, new geochemical measurements have thrown the planetary science community back into doubt. We are either modelling the wrong process, or modelling the process wrong." Should ()new theories of the moon's origin become a new thread, I'll post some links.

I put there for the cautionary advice that applies to all systems modelling, especially when many proxies are used in place of the reaL deal.

 

[jim mcnamara]

@CapnGranite
Astrobiology seems to behind a paywall, specifically the first article: DOI: 10.1089=ast.2009.0360
Since there are several of these, $US 51.00 for each one. Geosociety.org papers - same thing.

@D H - are there any open access "seminal" papers on oxygenation of the Early atmosphere, that are comparable? I am assuming you can see these.

 

[Evo]

I think what cookiemonster is asking is simply "where did the first water on Earth come from? Perhaps we should just stick with that question. @CapnGranite I think a couple of papers you attempted to link might have more detail than the article I linked.

 

[CapnGranite]

http://news.nationalgeographic.com/news/2014/10/141030-starstruck-earth-water-origin-vesta-science/
Mystery of Earth's Water Origin Solved
Instead of arriving later by comet impact, Earth's waters have likely existed since our planet's birth.
"The study shows that Earth's water most likely accreted at the same time as the rock," said Marschall.

This is the only unlocked paper/article I have on the computer.

While this isn't open-access, Science magazine is in many libraries. This is one of the most recent papers on the origin of the Earth's water.
http://science.sciencemag.org/content/sci/346/6209/623.full.pdf
Early accretion of water in the inner solar system from a carbonaceous chondrite–like source
ABSTRACT:
Determining the origin of water and the timing of its accretion within the inner solar system is important for understanding the dynamics of planet formation. The timing of water accretion to the inner solar system also has implications for how and when life emerged on Earth. We report in situ measurements of the hydrogen isotopic composition of the mineral apatite in eucrite meteorites, whose parent body is the main-belt asteroid 4 Vesta. These measurements sample one of the oldest hydrogen reservoirs in the solar system and show that Vesta contains the same hydrogen isotopic composition as that of carbonaceous chondrites. Taking into account the old ages of eucrite meteorites and their similarity to Earth’s isotopic ratios of hydrogen, carbon, and nitrogen, we demonstrate that these volatiles could have been added early to Earth, rather than gained during a late accretion event.
"Our findings cannot preclude a late addition of water for Earth with a carbonaceous chondrite–like D/H, but the observation indicates that a late addition of water is not necessary"

 

[Evo]

http://news.nationalgeographic.com/news/2014/10/141030-starstruck-earth-water-origin-vesta-science/
Mystery of Earth's Water Origin Solved
Instead of arriving later by comet impact, Earth's waters have likely existed since our planet's birth.
"The study shows that Earth's water most likely accreted at the same time as the rock," said Marschall.

Thank you. I think this probably won't satisfy CookieMonster's question of how water could have formed (H2O) if there was no oxygen present to create the water. Was there oxygen present when the Earth formed and the water was created or was that not necessary, this is where it really gets out of my realm of armchair reading.

I know one of you knows the answer.

 

[CapnGranite]

The water existed as ice before the Earth was formed.

http://www.cosmos.esa.int/documents...oloS.pdf/6e43745b-f365-4c8c-811c-e679c5fd1a54
Interstellar Water Ice Formation: A laboratory perspective

That was in
http://www.cosmos.esa.int/web/herschel/water-in-the-universe-from-clouds-to-oceans
WATER IN THE UNIVERSE: FROM CLOUDS TO OCEANS
The conference covered all astrophysical aspects of water, including the water trail, from the formation of water in molecular clouds to water on planetary bodies, including in our own solar system; water as a probe of physics and and chemistry; and water in nearby to water in extragalactic and high redshift sources.

 

[Jon Richfield]

Sorry, I can't make any sense of this. Do I understand that the question is why/how oxygen atoms were originally present on Earth as it emerged from the condensing solar system cloud?

Of course there were oxygen atoms (almost all of them chemically combined of course), lots and lots of them. Our parent supernova(e) plus its parent sun(s) produced elements eventually up to the transuranics, including Pm and Tc, though not all of them in the same concentrations and not all of them lasting long. Oxygen, Si, and Fe were among the commonest (surprise) and in the eventual settling out of various substances, Si and O wound up in the crust in huge proportions. However, there also were fair amounts of H, S, Li, Na, C and the whole alphabet soup, enough that only traces of free O2 or O3 ever existed, and that transiently when it did. But water was fairly plentiful and so were various other hydroxides and hydroxyl compounds. We call such things oceans, right?

The problem was not where the O atoms (in compounds) came from; they were there. The problem was where the free oxygen came from, because O2 is so reactive. That was where photosynthesis came in, and after it had been going for a while, given the plentiful quantities of CO2 and H2O to work on, we wound up with lots of O2.

So OK, I'm stupid; what's the mystery?

 

[Jon Richfield]

It might help to add, that if we look at any sort of chemical mess in a mud-and-rock ball such as early Earth, with all sorts of compounds being mixed up in heat and cold and radiation and what not (no life yet!) the range of reactions that we might expect, and the mutual co-precipitations and crystallisations would ensure that all sorts of compounds would form, change and re-form, always favouring the most stable forms under reigning conditions and equilibria. Hence plenty of H2O, NH3, CO2, SiO2 and so on.

Right?

 

[jim meyer]

This explanation about life force generating free oxygen ignores the fact that more than 90% of the CO2 on our planet is locked up in rocks by nonliving force. All that locked up CO2 was in the atmosphere early on in Earth's history. The rocks have the truth and it has not yet been discovered by science so a little humility, please.

 

[CapnGranite]

Depending on the redox conditions as the Earth was in that early stage of differentiation and degassing, chemical species were forming and disappearing. Jon Richfield has is correct, as I see it, but it was a bit more complex. I'm not so sure that O2 increases in the atmosphere came from the rise of bacteria alone. After the initial, and probable high S and CO2 period, there is evidence that degassing and reactions shifted that environment to one favorable for stable O2. At the same time, stromatolites and free-floating bacteria added to the atmospheric oxygen.
There is a a lack of humility in saying " All that locked up CO2 was in the atmosphere early on in Earth's history."

 

[Jon Richfield]

... it was a bit more complex. ...
There is a a lack of humility in saying " All that locked up CO2 was in the atmosphere early on in Earth's history."

Whenever we deal with processes on planetary scales, you can be pretty darn certain that it will be more complex than anyone had guessed.
I suspect that we have about as much CO2 as Venus, only ours is mainly in rock that would not have been able to hold onto its CO2 at Venusian temperatures.

But bottom line remains: Earth had plenty of oxygen from earliest days on.

 

[jim meyer]

Well let's not nitpick-I agree photosynthesis has added O2 to the atmosphere. My point is free oxygen has always been in the atmosphere at about 10E18kg or so. The fact that much more CO2 was in the early atmosphere(CO2 now in rocks)and dwarfs the other gases. This is not known and I just want you to do a calculation of how much CO2 rocks like calcite, dolomite and other rocks have absorbed from the early atmosphere. Not rocket science in any way.

 

[CapnGranite]

Understanding the Carbon Earth is not rocket science, for sure. It's also best left to another thread. I'm not sure calculating "how much CO2 rocks like..." is a particularly fundable project, or insightful.

 

[jim meyer]

The two gases are linked and very important to get right. As current state of art theory says the free oxygen came from CO2-right? The rub is that there is way too much CO2 locked up in rocks to be covered by the photosynthesis theory. The Bulk of the original CO2 had to have been locked away in rocks before any living thing would have had an environment to survive in. And photosynthesis generates hydrocarbons not calcite.

 

[CapnGranite]

a lot of ocean flora end up precipitating calcite or other carbonates

 

[jim meyer]

Well OK if life force did the job. The job still had to be done before the environment was fit for life capable of doing photosynthesis or before the job of freeing oxygen can be done. Now we have a chicken/egg problem as in which comes first. Is there a life form that can live in CO2 atmospheres?

 

[Fervent Freyja]

Well OK if life force did the job. The job still had to be done before the environment was fit for life capable of doing photosynthesis or before the job of freeing oxygen can be done. Now we have a chicken/egg problem as in which comes first. Is there a life form that can live in CO2 atmospheres?

Bacteria.

My take on this ordeal: Prior to ocean formation the atmosphere had been mainly hydrogen, helium, methane, and ammonia. It is now believed that much of the water and rock had been locked into the crust, at the same time, during formation and that a small contribution was made by water-rich meteorite impacts. A lot of volcanic activity released water vapor into the atmosphere, along with carbon dioxide; which, then formed heavy clouds over the Earth that rained for a long time- eventually, forming the ocean. Water came first, not oxygen.

 

[CapnGranite]

Except that I think the evidence is increasing for the water-rich meteorite impacts not being necessary for the primary ocean formation. The volcanic activity suggests that deeper-seated water was brought to the surface by tectonic activity and the volcanism. The later bombardment by water-rich meteorites added to the water volume. I suppose there are two camps regarding the origin of the oceans, water-enstatite grains along with other mineral material, accreting to for the Earth and the group that invokes the bombardment as being the primary source of water. Since around 2011 and up to today, everybody I know and have spoken to favors the first model.

 

[Fervent Freyja]

Except that I think the evidence is increasing for the water-rich meteorite impacts not being necessary for the primary ocean formation. The volcanic activity suggests that deeper-seated water was brought to the surface by tectonic activity and the volcanism. The later bombardment by water-rich meteorites added to the water volume. I suppose there are two camps regarding the origin of the oceans, water-enstatite grains along with other mineral material, accreting to for the Earth and the group that invokes the bombardment as being the primary source of water. Since around 2011 and up to today, everybody I know and have spoken to favors the first model.

I do think you are right. It may be more right to say that water was locked into the crust as material accreted and later impacts may have contributed some.

Still, this explanation doesn't satisfy me. Something is off. Looking at all the advancements we have made (look at what we can describe about the universe) and comparing it to how little we can explain about the formation of the early Earth makes me uncomfortable.

 

[CapnGranite]

I am happiest when I have a rock to crack open with my rock hammer. In the past, in oil exploration, the drilling sample and cores from an exact depth were what was "real". The seismic sections that we relied on to select the spot to drill gave us data that we manipulated to create the profile. The validation of the seismic data came with a real sample from that data. In recent years I've been involved in about a dozen diamond anvil cell experiments. The results are what they are, but I feel a bit uneasy about extrapolating the results from that tiny universe to the interior of planets. The work that the consortium that is the Deep Carbon Observatory has revealed an Earth interior that would have been pure science fiction in the late '60s, when I first got interested in that.

Something that keeps things in perspective is the notion of multiple-working hypotheses. Even though carrying along old ideas is getting cumbersome, I don't reject them outright for the most part. I run with what works until there is a problem. Sometimes looking back at older ideas can provide insight. If I'm not editing a paper, I try to read 4 papers a day out of the 20-50 I download 6 days a week. I mention all this to show how hard it is to synthesize all the information into something coherent and insightful in a platform like this forum.