Friday, July 25, 2008

Rethinking Mantle Plumes



New Scientist: Volcanoes may not be fed by magma 'mushrooms'

THE plumes of hot magma that fuel the volcanism of "hotspots" like Hawaii and Iceland have long been thought to be efficient conduits of Earth's fiery contents. Yet it seems they can be rather lacklustre on their way to the surface.

We traditionally picture the plumes of hot magma that rise through the mantle as mushroom-shaped with a thin stalk feeding a bulbous head, or hotspot, beneath the crust. However, seismic imaging in Iceland reveals a patchy structure without a stalk, leading some researchers to suggest there are no plumes at all.

Ichiro Kumagai and colleagues at the Paris Institute of Earth Physics in France reckon they can explain these patchy structures. They created plumes by heating the base of a tank containing sugar syrups of varying densities, to simulate the composition of the mantle. The densest material was heated just enough to rise and create the core of the plumes, but as it rose it also cooled, so its density increased once more to match or slightly exceed that of the surrounding material. This caused the core to either stall or sink, while the less dense material [aka oil] separated and continued rising (Geophysical Research Letters, in press).

John Brodholt of University College London says the model "seems to explain some of the observations used to argue that plumes do not exist".
If true, this illuminates and adds color to petroleum formation.

15 comments:

  1. "BREAKTHROUGH" WORKING MODEL DEMONSTRATES ABIOTIC MANTLE/CRUST TRANSPORT

    (Great catch OilIsMastery!)

    This hypotheical model gives great insight into the volcanic processes of Abiotic Theory. One can now draw a picture that demonstrates and explains how petroleum and other minerals "transport" to the near crustal surface. And just as important, why oil rises toward the surface when magma and other minerals do not.

    The operative sentence, as OilIsmastery points out is: "This caused the core to either stall or sink, while the LESS DENSE (emphasis added) material separated and continued rising."

    OilIsMastery is right to add parenthetically "aka oil" into the sentence. For oil is less dense than almost all other minerals.

    Now, this hypothetical model specifically addresses situations where no molten magma erupts to the surface, such as would be the case at many points along the edge of a tectonic plate. 67% of large and giant oilfields are found above the tectonic faults of the world.

    It also explains why oil is found in conjunction with basaltic dikes (magma that rose toward the surface, but solidified before erupting) like in central Siberia, in the area known as the Siberian Traps.

    But it also can be adapted to explain oilfields that flank volcanoes and why sulphur is found in association with oil.

    Observations have been made that solfataric vents flank a magma erupting central vent (volcano).

    This explains why oil deposits are found flanking volcanic vents, New Zealand oilfield flanking a volcano and another New Zealand oilfield flanking a volcano and, of course, Indonesia also has oilfields flanking volcanoes.

    The volcanic examples I gave above according to the model would be where the central core of the "uplifting" hot spot was hot enough to breach the surface, while the model explains how less dense material would keep rising away from the central magma vent where magma doesn't.

    In Sicily, there are mud volcanoes that emit natural gas on the flanks of Mt. Etna.

    I think the model can be adapted to provide the visual image and explanation for the above oilfields as well.

    It gives a visual image why oil continues toward the surface when other volcanic materials don't breach the surface.

    In essence, why volcanic material is present where there are no apparent volcanoes.

    This hypothetical model is a breakthough at understanding how and why petroleum transports to the crust and then continues to travel up through the sedimentary layers to eventually become trapped in geologic reservoir formations or even emerge on the surface like it does in Iraq or in the Californian heavy oil seeps.

    This model answers the previous challenge made by BrianR, a contributor to the Oil Is Mastery website:

    "... if I accept the thermodynamical and chemical foundation of abiotic theory as Kenney lays out, I need to then see the concepts within the context of plate tectonics and what we think we know about the composition and evolution of the upper mantle and lower crust."

    And: "I'd like to see some diagrams like that for abiotic concepts."

    I submit this hypothetical working model goes a very long way to answering that challenge.

    This model with continued refinement and further experimentation should continue to increase our understading of Abiotic processes within the interior of the Earth.

    This is one more piece, albeit a very important piece, of the puzzle for identifying and explaining the Abiotic Hydrocarbon Cycle:

    Formation
    Transport
    Travel
    Repose

    And, other unknown geologic processes:

    "Volcanology is one of the oldest branches of geology; it is also one of the least developed." -- Howel Williams, 1953

    And,

    "Next to nothing is known about the sources of the volatile components of magmas or how they are distributed and transported between the mantle and the shallow levels of the crust." -- Howel Williams, 1979

    Finally,

    "Geologists engaged in the search for oil and gas fields ought now to begin reappraising the facts at their disposal and analyzing them from positions of crustal fault tectonics." -- Ivan I. Chebanenko, 1966

    Great catch, again, thanks OilIsMastery.

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  2. Postscript: Please click the link provided in the post by oilIsMastery. You will find a video (akin to Youtube) that can be played that demonstrates the model actually working. You can see for yourself what the article is describing: "breakthrough" Abiotic model demonstrates mantle/crustal transport.

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  4. I'm not sure that my mantle plume necessarily does justice to the fluid dynamics of it all.

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  5. The paper you link to doesn't discuss abiotic theory ... you may interpret their results as evidence for abiotic theory, but their work doesn't explicitly "demonstrate" it as you say. That is, they (the authors of that paper) don't even mention abiotic petroleum ... you are the one taking their results and using it as evidence. Which is fine, this is science. But, I just wanted to point out that difference.

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  6. Hey Brian, according to biotic theory, how exactly are diamondoids supposed to get into the petroleum?

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  7. The paper I link to doesn't discuss biogenic theory either. Nowhere do they say petroleum comes from fossils or biological molecules.

    And yes I do interpret their results as yet more evidence for abiotic theory.

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  8. BrianR:
    As OilIsMastery has agreed, yes, the authors don't mention Abiotic Theory, but as OilIsMastery also pointed out, neither did they mention "fossil" theory either.

    Which, actually, makes it a better study because the results weren't influenced by the authors' biases and prejudices, for or against either "fossil" theory or Abiotic Theory.

    The study was done strictly in accordance with the laws of fluid dynamics as developed by that discipline of science using a scaled fluid dynamics model.

    It's well known that fluid dynamic is "scale independent" meaning when studying fluid dynamics one can use scale models.

    The mystery of the Channelled Scablands is a classic case of fluid dynamics helping to solve a geologic process that was not well understood and, infact, was highly controversial: "Debate over the origin of the Scablands raged for four decades and is one of the great debates in the history of earth science."

    "When first studied, no known theories could explain the origin of these features."

    "Bretz's theories [the first to ascribe cataclysmic flooding] met with vehement opposition from geologists of the day, who tried to explain the features with uniformitarianism theories."

    There you go, again, geology's bias for Uniformitarianism, blocked the correct interpretation of the formation of the Channelled Scablands for decades.

    The Channelled Scablands in Washington State is an example where scaled fluid dynamics helped solve the mystery.

    "Many fluid flow phenomena are scale-invariant; they look the same regardless of size."

    I bring attention to the past geological controversy over the Scablands to point out geology's previous errors and show how scaled fluid dynamics impacted that controversy.

    Getting back to the question at hand: Again, the fact that the authors are not influenced by biases and prejudices in the Abiotic Theory versus "fossil" theory debate makes it an ideal study.

    Yes, it's encumbent on Abiotic Theory to "make the case" that the study "demonstrates" Abiotic Theory.

    The scientific evidence is substantial that petroleum does act in accordance with this particular scaled fluid dynamic model. Thus, one can state that this model demonstrates the transport mechanism of Abiotic Theory.

    Further, this model can be used to explain observations of specific geological phenomenon and specific geologic formations.

    In that sense, it's a very powerful "tool" for abiotic Theory.

    In essence, this scaled fluid dynamic model explains why there is 'volcanic' material, petroleum, where there is no apparent volcanic vents.

    I have argued for some time, now, that oil's unique physical properties, a liquid and low density relative to other minerals, were the key reason oil "transported" in the mantle to the crust and then "travelled" toward the surface, once in the crust.

    This model, now, gives us a visual image and a further refined explanation of the specific dynamics involved. It identified -- not by name, but by physical properties (an even better identification) -- oil: "...the less dense material separated and continued rising," so, shows that oil does, indeed, have a geologic mechanism for transport from the mantle where it forms into the crust and beyond.

    Of course, that case must be made many times over to satisfy those in the geologic community that are most attached to "fossil" theory.

    This model allows the above to be done.

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  9. Hey guys, take it easy, as I said ... I realize you are using their results as evidence for YOUR theory. That's fine. I'm not saying you can't do that. But, the language of the post and comments implies that THEY talked about petroleum (of whatever origin) explicitly. That's all. If you were to write a paper and cite this paper for that explicit result, the reviewers would catch it and tell you the same. But, you could cite them for the model, and then conclude what it means for abiotic mechanisms. This is essentially what you've done here ... i'm just nitpicking the wording. I'm currently revising a couple papers and dealing w/ details such as this myself.

    I agree ... the Scablands stuff is fascinating. You can see the bedforms on GoogleEarth.

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  10. To BrianR:
    I appreciate your comments, as I said before, the comments press me to clarify and extend my thinking to better demonstrate and explain Abiotic Theory.

    That's a good thing.

    BrianR says: "...the language of the post and comments implies that THEY talked about petroleum (of whatever origin) explicitly."

    What language?

    OilIsMastery's obvious parenthetical, "[aka oil]"? Or my assertion that the model "demonstrates" abiotic principle?

    You're right when you say, "I'm just nitpicking the wording."

    That's the real story.

    BrianR, if you had one valid scientific criticism, you would have stated your criticism, but because you didn't have a single scientific point to make, you were left "nitpicking" the words.

    I'd rather get from you a meaningful scientific response.

    After all, this model, now, gives us a visual image and a further refined explanation of the specific dynamics controlling Abiotic Theory based on scientifically recognized principles of fluid dynamics.

    Especially since it answers your prior objection: No mechanism for petroleum "transporting" to the crust and beyond.

    Yes, the real story is your scientific "silence" in the face of the hypothesis asserted in this post and comments.

    Maybe that speaks louder than words.

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  11. Meanwhile, as the Oil Is Mastery website is scientifically mastering the Abiotic Hydrocarbon Cycle, "fossil" theory is left to explain why there are sedimentary areas that don't have any oil?

    Which raises the question: How do we know there are sedimentary areas that don't have any oil?

    Because, without seismic imaging, which can literally "see" the oil and even tell how much oil is in a given reservoir, "fossil" theory, alone, leads to a success rate of one (1) out of 28 bore holes hitting oil, the rest are worthless dry holes.

    This leads to the unescapable conclusion that many sedimentary areas that "fossil" theory predicts should have oil, in fact, are barren of oil.

    So the question is apt: Why are there sedimentary areas that don't have any oil.

    It is simple: Oil is not formed in sediments, but rather uses sedimentary layers, 'roofrock' as conduits to geologic reservoir structures.

    The actual determining factor is the crustal fault tectonics in a given area. There are areas in the world where sedimentary layers have built up, but aren't situated above any "source faults."

    Hence, there is no oil.

    "Fossil" theory has yet to "come to grips" with this inconvenient truth.

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  12. So, do you hypothesize that all volcanos contain oil or just some?

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  13. Quantum Flux, great question and thank you so much for asking. It's not a hypothesis, it's an observation. I'm about to post on this and you'll be able to see clearly.

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  14. Anaconda says: "Yes, the real story is your scientific "silence" in the face of the hypothesis asserted in this post and comments. Maybe that speaks louder than words."

    You win! You're absolutely right ... I'm a disgrace and ignorant.

    I tried to comment on the newer post, but in case it doesn't come up, I'm done with you guys. Good luck with your theories.

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  15. Theories.... good luck with your violation of thermodynamics.

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