From the American Association for the Advancement of Science, this press release was for some reason included in the atmospheric science category of Eurekalert.
Carbon cycle reaches Earth’s lower mantle, Science study reports
Evidence of carbon cycle found in ‘superdeep’ diamonds From Brazil
This release is available in Portuguese and Spanish.
The carbon cycle, upon which most living things depend, reaches much deeper into the Earth than generally supposed—all the way to the lower mantle, researchers report.
The findings, which are based on the chemistry of an unusual set of Brazilian diamonds, will be published online by the journal Science, at the Science Express Web site, on 15 September. Science is published by AAAS, the non-profit, international science society.
“This study shows the extent of Earth’s carbon cycle on the scale of the entire planet, connecting the chemical and biological processes that occur on the surface and in the oceans to the far depths of Earth’s interior,” said Nick Wigginton, associate editor at Science.
“Results of this kind offer a broader perspective of planet Earth as an integrated, dynamic system,” he said.
The carbon cycle generally refers to the movement of carbon through the atmosphere, oceans, and the crust. Previous observations suggested that the carbon cycle may even extend to the upper mantle, which extends roughly 400 kilometers into the Earth. In this region, plates of ocean crust—bearing a carbon-rich sediment layer—sink beneath other tectonic plates and mix with the molten rock of the mantle.
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  IMAGE:This figure shows the location of the Juina-5 kimberlite in Brazil, where the raw diamonds come from. Thousands of diamonds are examined in order to identify stones that might contain…Click here for more information. |
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Seismological and geochemical studies have suggested that oceanic crust can sink all the way to the lower mantle, more than 660 kilometers down. But actual rock samples with this history have been hard to come by.
Michael Walter of the University of Bristol and colleagues in Brazil and the United States analyzed a set of “superdeep” diamonds from the Juina kimberlite field in Brazil. Most diamonds excavated at Earth’s surface originated at depths of less than 200 kilometers. Some parts of the world, however, have produced rare, superdeep diamonds, containing tiny inclusions of other material whose chemistry indicates that the diamonds formed at far greater depths.
The Juina-5 diamonds studied by Walter and colleagues contain inclusions whose bulk compositions span the range of minerals expected to form when basalt melts and crystallizes under the extreme high pressures and temperatures of the lower mantle.
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 IMAGE:Raw diamonds are screened for those hosting inclusions. The key to discovering the minute inclusions is meticulous polishing of the diamonds on a jeweler’s polishing wheel.Click here for more information. |
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Thus, these inclusions probably originated when diamond-forming fluids incorporated basaltic components from oceanic lithosphere that had descended into the lower mantle, the researchers have concluded.
If this hypothesis is correct, then the carbon from which the diamonds formed may have been deposited originally within ocean crust at the seafloor. A relative abundance of light carbon isotopes in the Juina-5 diamonds supports this idea, since this lighter form of carbon is found at the surface but not generally in the mantle, the authors say.
The diamond inclusions also include separate phases that appear to have “unmixed” from the homogenous pool of material. This unmixing likely happened as the diamonds traveled upward hundreds of kilometers into the upper mantle, the researchers say.
After the diamonds formed in the lower mantle, they may have been launched back near the surface by a rising mantle plume, Walter and colleagues propose.
This research was supported by the Natural Environment Research Council and the National Science Foundation.
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Yes, the deep hot biosphere exposes the myth of “fossil” fuels:
http://en.wikipedia.org/wiki/Abiogenic_petroleum_origin
“what am I to think?”
Thinking at all would be a start. This release is completely innocuous and actually quite interesting – yet you have to dress it up with irrelevant references to Al Gore and CO2 emissions when neither have anything to do with it. Very weak.
And if crustal carbon is making it this deep that blows a wide gaping hole in the “abiotic” oil idea.
biogenic hydrocarbon signatures are difficult refute. Maybe the depths of the crust, even the mantle are teeming with chemosynthetic organisms. There are some truly weird organisms living deep within the vents at the bottom of the ocean.
From the article…
“This study shows the extent of Earth’s carbon cycle on the scale of the entire planet, connecting the chemical and biological processes that occur on the surface and in the oceans to the far depths of Earth’s interior,” said Nick Wigginton, associate editor at Science.”
Most *MOST* of the carbon on this 3rd rock from the sun *IS* stored in rocks (In their heads). SHEESH!
FredT think about this:
If the “carbon cycle” reaches to the mantle, then when diamonds eventually come to the surface, how do they continue in the cycle? Last I heard, they don’t interact with much. There’s no cycle otherwise.
This study, citing “carbon cycle” seems to only include the phrase in passing, perhaps as a way to get funded. There’s lots of “may haves” and “could haves” in that press release. Think about that.
I wonder if this planet is the end game for our planet? Oh wait they didn’t find any SUVs, CO2 or water.
“Astronomers discover planet made of diamond”
“The new planet is far denser than any other known so far and consists largely of carbon. Because it is so dense, scientists calculate the carbon must be crystalline, so a large part of this strange world will effectively be diamond.”
http://www.reuters.com/article/2011/08/25/us-planet-diamond-idUSTRE77O69A20110825
4 days left to watch,
http://www.bbc.co.uk/programmes/b0148vph
The Core, half way through the program a description of the solid inner core including its temperature.
4700 kelvin the same as the surface of the sun, not millions of degrees.
Worth watching if you can
Diamonds are quite old. Many million years to a couple of billion or more. (max 4.6billion). So these ‘scientists’ think that carbon found in diamond is pollution. C**p.
Carbon is found in the sun so it is odds on that this planet has carbon mixed in with everything else in the mantle. In fact petroleum has been found in igneous rock so it may itself be formed there, or at least some parts of it.
A crackpot theory? We will see but discoveries of petroleum seem to be found in places that were discounted when considering the existing theory of formation. I am open to any discussion.
Re:FredT says:
September 17, 2011 at 6:20 am
“This release is completely innocuous and actually quite interesting – yet you have to dress it up with irrelevant references to Al Gore and CO2 emissions when neither have anything to do with it. Very weak.”
Although publishing the subject paper in the “atmospheric science” category does seem rather odd, I have to agree with Fred on this one. That brings me to another question: “Are Gore’s antics driving us all mad as hatters?”
I hope those researchers are doing this research on their own dime. I wouldn’t pay them a cent myself.
What’s the estimated wave length of this cycle? Is it millions or billions of years? It can’t be considered a rapid climate changing factor. The study does show that their are inorganic processes that fractionate and redistribute the two stable isotopes over long time periods. That observation calls into question the use of the C 13/12 index as evidence that burning fossil is the primary cause of the accumulation of CO2 in the atmosphere. There are more rapid inorganic fractionation and redistributing processes that can affect atmospheric C 13/12 values.
Let us assume that there exists some level of validity to the study. In principal, I see nothing major wrong with it, other than (possibly) the time scale of the events they describe.
If the study is suggesting that PRESENT-DAY CO2 concentrations are showing up in the Brazilian diamonds, then we have a problem. The subducted sea-floor (and its attendant sediments), going through a melting process, then rising through the crust, and emplacing the diamond-bearing kimberlites, would have required some tens of millions of years to complete one “cycle”. At the earliest, the “carbon” showing up in these super-deep diamonds, would be from the Cretaceous, or possibly the early Paleogene (Paleocene/Eocene, for those on the west side of the pond).
The press release, and Anthony’s summary are just a bit ambiguous on this point. If the paper is posted somewhere, I will do my best to critique it, should it show up.
Not being critical of you Anthony; I am actually a vigorous supporter of your work, and will do whatever I can to help out. Love WUWT, and try to visit often.
Best regards to all,
Mark H.
It is almost beyond bizarre that the well know phenomenon of diamond creation somehow gets tarred with some sort of perverse brush to create some kind of weird pseudo connections between diamonds and the inferred ‘pollution’ related to the carbon cycle.
Shameless huckstering – the diamond fluid inclusion academics (working on this ‘problem’ since the 70’s (H.O.A Meyer)) are trying to latch onto the AGW bandwagon. It revealw the breadth of the scientific corruption….
Ugh.
William Abbott says:
September 17, 2011 at 6:35 am
There are some truly weird organisms living deep within the vents at the bottom of the ocean.
Allow me a slight correction: the organisms of which you speak live adjacent to these hydrothermal vents, which erupt sulphide-rich brines (with lots of CO2) into the adjacent seawater. Temperature probes show highly superheated water up to 460C, which does not flash to steam because of the deep-sea pressures. Any bug trying to live “in” this plume would have to be a heckuva swimmer!
And oh dear, one mustn’t forget calcium CARBONate, among others.
Oh dear, do you realize this means that carbon sequestration in old natural gas wells isn’t deep enough to keep it from coming back? We’re gonna have to pump it 600 km deep to be safe! 🙂
Setting aside the “carbon pollution” and even “carbon cycle” comments, these look like fascinating samples for study.
Anthony Watts says:
September 17, 2011 at 6:38 am
It’s true that diamonds are forever and thus the carbon that composes them is effectively removed from the carbon cycle. What probably isn’t true is that all biotic carbon that reaches great depth turns into diamond. One might reasonably suppose only a diminishingly small fraction of it does and that the remainder remains free to participate in the carbon cycle.
This was a pretty innocent article and your knee jerk reaction to it was less than thoughtful and some might even call it downright ugly.
Your headline was a “if it bleeds it leads” kinda thing. Not one of your better moments.
@Pamela Ah, well, maybe it just struck me wrong I was quite taken aback to find it in the atmospheric press release section of Eurekalert…it seemed frivolous. – Anthony
@Pamela @Doug @FredT
I decided that my lead in comments were a bit over the top, probably owing to how miserable I feel today. I was up at 5:30AM, with an ear infection, and it’s my birthday.
So I’ve deleted my intro comments except for my surprise at the inclusion into the atmosphere science section of Eurekalert, and will let the article stand on it’s own merits and faults sans my commentary.
I’m done for the morning, the clinic is open now, so headed there. – Anthony
I agree with FredT that this is an interesting story, but then again I am a geologist. I also reluctantly agree with Fred that Anthony went a bit far in tarring the story with the Al Gore reference, but I do get Anthony’s point about the placement of the press release.
Yet another field that can’t perform experiments is heard from. “Sciences” that don’t have a performance principle frequently end up being science fiction. See Cosmology for the grand-daddy of fictional -ologies.
Happy b-day! We all hope you feel better asap. A beautiful day here in Norcal–go soak up some sun!
Get better Anthony, you have far more friends rooting for you (and your and yours health).
Subduction zones (at the edges of some plates) feed material to the upper mantle. From there the currents in the mantle would spread them all over, but how they spread out is largely a mystery. It’s well known that some of the water, after getting super-heated and pressurized at depth, dissolves sulphur, copper, lead, zinc, molybdenum, silver, gold… it’s a long list, but I’ll stop there. When the pressure builds up high enough it can fracture the rock around it, forcing its way outwards and eventually losing pressure and/or temperature enough that the metals are dropped from suspension. Do this hundreds of thousands of times, and you can get a porphyry deposit, some of which are among the largest mines in the world. Black smokers at depth are doing the same things, hydro-thermal fluids high in metals that precipitate out when they hit the relatively cold and low pressure deep sea waters. These beds of oceanic deposition are called massive sulphides, and are among the richest mines in the world when they come to or near surface.
er, far more friends rooting for you than you know. I must remember to finish typing one thought before developing the next. 🙁