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Sea-Floor Sunday #22: A actively-growing mound on the sea floor

June 22, 2008

This week’s Sea-Floor Sunday is a quick one.

A paper came out in Marine Geology last month (v. 250, p. 258-275) about a methane-seeping, actively-growing sea-floor mound in Santa Monica Basin (offshore Los Angeles, CA).

It’s like a zit on the sea floor!!

In the perspective bathymetric image below, note the depth scale (colors) and the distance scale (in red by bottom of image). This is a big zit!

What’s more is that the mound hosts a biologic community … a chemosynthetic community of organisms. In addition to the mapping and profiling of the feature, they also took some photographs and did some sampling of the mound. Very cool stuff.

The first author is a marine geologist from the Monterey Bay Aquarium Research Institute (MBARI) … they have a fantastic website about all the geologic and biologic research they do in the deep sea and submarine canyons. Check it out here.


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41 Comments leave one →
  1. June 22, 2008 11:56 am

    This is an excellent post, this writer appreciates the color graphic of the “zit,” and accompanying physical description.

    This writer, with admittedly limited geological background, thinks the depicted geological formation could be some kind of hydrocarbon deposit.

    Is that a fair assessment?

  2. June 22, 2008 9:07 pm

    Here’s a relevant statement from the abstract of the paper regarding your question:

    “Continuous streams of methane gas bubbles emanate from the crest of the northeastern mound, and extensive methane-derived authigenic
    carbonate pavements and chemosynthetic communities mantle the mound surface. The large local vertical displacements needed to produce these
    mounds suggests a corresponding net mass accumulation has occurred within the immediate subsurface. Formation and accumulation of pure gas
    hydrate lenses in the subsurface is proposed as a mechanism to blister the seafloor and form these mounds.”

  3. June 22, 2008 10:31 pm

    Abiotic methane zit? This is wonderful news.

  4. June 23, 2008 4:37 am

    An interesting juxtaposition of biology and geology! Possibly good for the next Accretionary Wedge.

  5. June 23, 2008 6:22 am

    Anaconda … you obviously haven’t read the paper … they don’t interpret an abiogenic origin. If you disagree, state why in detail for THIS site (i.e., do not respond with a long, rambling comment about abiogenic theory in general, I will delete it).

    If you don’t agree with their interpretation, analyze the data yourself, reinterpret and write a paper. If you don’t like their data, collect your own, and report the results.

  6. June 23, 2008 7:53 am

    correction: the above comment is to “OilIsMastery” who explicitly stated this feature is abiogenic

  7. June 23, 2008 11:59 am

    BrianR: My pleasure.
    Obviously, they don’t because they don’t subscribe to Abiotic Theory.
    Abiotic Theory is a rival “school” to the Uniformitariansm doctrine that underlies Geological Theory, so no surprise you also reject Abiotic Theory.

    To the point: The geological feature depicted has methane emanating from it and is “growing” this is consistent with ‘solfataric’ vent activity. There is evidence of ‘solfataric’ activity onshore in association with hydrocarbon deposits. ‘Solfataric’ activity is a key association in Abiotic Theory. The “growing” of the mound suggests “active pressure” under the mound from a specific ‘point source’. Methanehydrate formation as proposed under conventional geology would not concentrate in a ‘point source’ with sufficient pressure to raise this mound, but, rather would emanate from a diffused field with out mounds.

    “The large local vertical displacements needed to produce these mounds suggest a corresponding net mass accumulation has occurred within the immediate subsurface.”

    In other words, “some” substance under pressure is pushing up from below.

    From what you have kindly provided of the paper in question, the authors assume the “continuous streams of methane gas bubbles” are from methanehydrate. This writer doesn’t make that assumption.

    The paper “[has] proposed” an explanation of the feature as a “pure gas hydrate lenses,” or ‘focus of gas’. But the paper gives no explanation or description of the ‘geological mechanism’ which concentrates the gas or creates the ‘lense’, so by implication, not even the paper’s authors are sure what is the exact mechanism.

    This provides an opportunity for the Abiotic prospective to offer an explanation and description of the sea-floor feature.

    This writer suggests that methane or a combination of methane and oil is rising from a deep “source fault” in the basement related to the larger tectonic faults in the region, and thus migrates up through the stratigraphic column by way of vertical conduits causing this feature on the sea-floor.

    The key evidence in regards to Abiotic Theory of this sea-floor feature is the coninuous pressure at a specific point which is ‘solfataric’ in nature. Repeated and documented field observations have been made of the association between hydrocarbon gasses and ‘solfataric’ vents. This is more consistent with Abiotic Theory than “fossil” theory.

  8. June 23, 2008 12:42 pm


    Bringing up uniformitarianism is beyond the scope of this post, so I’d like to stick to the details of this paper if that’s okay with you.

    There’s a lot to cover in your comment … I only have time for one aspect at the moment, perhaps I’ll get to more later.

    You say: “…the authors assume the “continuous streams of methane gas bubbles” are from methanehydrate.”

    Where do they say the methane is from methanehydrate??

    Well, as it turns out…they don’t!
    Here’s what they actually say about the origin of the methane (p. 270):

    “This methane must be migrating from a gas reservoir at greater depth because the continuous flow observed coming from the crest of the NE Mound could not be sustained by local methane production”

    This discussion will be a lot easier if you don’t mis-quote the authors and then spend time refuting a statement that they didn’t even say.

    Please quote them directly.

  9. June 23, 2008 1:27 pm

    My apology for misquoting. This writer took,”…pure gas hydrate lenses…” to be short hand for methanehydrate. Again, my apology.

    This writer has looked at the abstract, through the kind auspices of your link, in Science Digest, but doesn’t have access to full paper.

    This is even more interesting after reading the abstract. Thank you.

  10. June 23, 2008 1:34 pm

    That must be Bill Normark’s last paper, or close to it.

  11. June 23, 2008 1:45 pm

    Andrew … indeed it is … he was involved in so many things, even during his final days, that he is a co-author on several papers that are still in review (including one of my own). He will still be publishing for another couple of years! I do miss him.

  12. June 23, 2008 2:04 pm

    Follow up: New information changes the discussion. The authors do, indeed, have a ‘geological mechanism’ for the gas to rise up to this sea-floor feature. Because of that additional knowledge, the part of my comment assigning no description of the ‘geological mechanism’ was wrong.


    The debate would turn on the usual disagreements between Abiotic Theory and Fossil Theory, and so with that realization in mind, this writer will give it a rest unless you have specific issues to cover.

    Best reards,


  13. June 24, 2008 1:02 pm

    Anaconda … I need to clear up another thing you say above:

    “…no surprise you also reject Abiotic Theory”

    I’m not sure where I rejected any theory (perceived skepticism is not rejection).

    I find your writing style obtuse and difficult to follow … it contains unusual capitalizations (are those proper terms?), no links, no citations, tons of quotation marks, mostly assertions … but hey, that’s just me.

    With regards to this topic, you seem to live in a dichotomous world in which whenever there’s some uncertainty that process A is occurring at a specific place/time, that means process B MUST be occuring and, if so, process B MUST also be occuring everywhere and at all times (thus disproving the mere existence of process A!).

    This all-or-nothing approach strives to amplify uncertainty (which is a fundamental consequence of characterizing natural systems; scientists live with this everyday) which is then used as reasoning to support an alternative that is presumed to be true by default.

    A wise person once said ‘whenever there are two hypotheses, there is sometimes a third hypothesis – a combination of the first two’.

    I’m not saying that’s the case here … just that your general approach to investigating scientific problems seems presume an absolute dichotomy.

  14. June 24, 2008 5:03 pm

    (1) That is of the order of (1.2km) x (0.6km) x (0.5km) = 0.48 km^3, right?

    (2) You said they did some sampling of the mound and concluded that there was a “chemosynthetic community of organisms”?

    (3) Was it just methane, or were there also hydrocarbons found in the sample?

    (4) If there were hydrocarbons in the sample, then were they directly synthesized by the organisms, or did they form under high heat and pressures?

  15. June 24, 2008 5:57 pm

    To BrianR:
    You don’t like my writing style? Fine, that’s your prerogative. The capitals are to state, unequivocally that Abiotic Theory stands as a rival “school” opposed to general principles of geology like Uniformitarianism and “fossil” theory, with its own terminology and concepts.

    As far as cites go — this is a blog, not a Ph.D. disertation.

    Come on, BrainR, your hostile response to OilIsMastery’s statement/question, that this was an “Abiotic methane zit?”, makes your comment ring hollow.

    This writer comes to the party, late. It was “fossil” theory for the last century that said Abiotic Oil was impossible, with “fossil” theory advocates saying, “99.99999% of petroleum was derived from organic detritus.”

    But to get specifically to your point: This writer has seen precious little evidence to support the idea that petroleum or any hydrocarbons are derived from organic detritus. Save for peat bogs and “brown” or lignite coal. The rest is of Abiotic processes in the mantle with emanation into the crustal environment in various forms.

    Abiotic processes dominate the Earth’s geo-mechanical processes. The fact that new scientific observations are undermining the study of geology’s historic underpinnings is too bad, and mostly due to a hide-bound approach that has been taken by the leaders in geology from its very inception as a “study.”

    However, this writer would like to extend an “olive branch” to any geologist possible because this is a quest for “truth for its own sake.” And this writer welcomes anybody who wants to “come reason together.”

    That’s when science moves forward in the spirit of the Greeks.

    You seem to be affecting an objectivity, which geology as a whole, “fossil” theorists in particlular, and your retort to OilIsMastery specifically, does not reflect.

  16. June 24, 2008 6:16 pm

    Anaconda … I said I found your writing obtuse and difficult to follow … and I didn’t mean it to be offensive. When one spends their time writing/editing/reviewing scientific papers, one tends to cut to the chase, so to speak.

    As for my retort to OilIsMastery, it was because he/she made a leap of inference and interpretation immediately … I apologize again for my response, but this is what happens in scientific conferences and literature … we challenge each other. It’s lively and exciting. If someone makes an interpretation w/out even reading the paper and addressing what the author’s present, I will take them to task. If the tone is curt, I’m sorry.

    Although this is not a dissertation, most bloggers/commenters who discuss scientific comments, do include links and citations from time to time … i’m not asking for a bibliography here.

    You say: “You seem to be affecting an objectivity, which geology as a whole, “fossil” theorists in particlular … does not reflect.”

    Geology as a whole??? Wow.

  17. June 24, 2008 6:53 pm

    Quantum Flux … I will try to address your questions … I apologize in advance if the answers aren’t what you’re looking for. You may not have access to the paper … but, I urge you to get it … I try and quote the paper below where appropriate, but this is why they wrote a whole paper. My quoting of segments of an 18-page paper do not do it justice.

    (1) Are your volume calculations of the entire topographically-positive feature shown in the bathymetric image above? I think that’s what you’re referring to … that is the anticline, a structural feature, which is a result of local compression within an overall strike-slip regime. That entire positive feature is NOT the mound that is the focus of the study … it is only at the top (the brownish stuff).

    (2) Yes, here’s part of the text about sampling: “Ten samples of the carbonate mantle of the NE Mound that were solid enough to be picked up with Tiburon’s [ROV] mechanical manipulator were recovered.”

    A bit of the results: “The shallowest area on this mound (800 mbsl) consists of a ~20 m long NW–SE oriented ridge. This ridge is composed of sediment-bare slabs of massive carbonate that form a nearly continuous pavement that extends down the mound’s northeast flank.” … and … “To the southwest of the summit is a >30 m wide terrace at ~802 m (Fig. 5B). This terrace is covered with extremely dense beds of small (~25 mm) living clams (Vesicomya elongata) and orange and white microbial mats that overlie a veneer of soft sediments (Fig. 2C).”

    They also did sampling for carbon and oxygen isotopes, pore water composition from the sediment, gas samples, and so on … as I say above, there’s just too much to put into a comment.

    (3) Here is a direct quote from the paper: “The sample of the venting gas collected underneath an inverted funnel was composed primarily of methane (99.22%) with trace amounts of ethane (0.0029%) and carbon dioxide (0.093%). The methane has a d13C value of −70.8‰(PDB) and a 14C content of <0.4% modern carbon.

    (4) As stated in a comment above, they interpret that the methane is coming from a deeper source as this relatively small community could not sustain a continuous vent of methane.

    Here’s more: “Venting of methane … through seafloor sediment stimulates … mixing [that] occurs between the rising gas and the overlying oxygenated and sulfate-bearing seawater. Anaerobic oxidation of methane (AOM) supports communities of chemosynthetic organisms (Sibuet and Olu, 1998), and induces rapid diagenetic changes within near-seafloor sediments (e.g., Paull et al., 1992; Greinert et al., 2000; Peckmann et al., 2001; Roberts, 2001). The most obvious manifestation of this early diagenesis is the formation of authigenic minerals, primarily methane-derived carbonates. Such carbonates are identified on the basis of their 13C-depleted cements and distinctive textures.”

    I hope this helps.

  18. June 24, 2008 7:59 pm

    Multiple working hypotheses.

  19. June 24, 2008 8:34 pm

    If I was a religious fundamentalist or uniformitarian geologist I would probably think the zit was formed by dinosaurs.

  20. June 24, 2008 9:13 pm

    “Geology is the prisoner of several dogmas that have had widespread influence on the development of scientific thought.” — William R. Corliss, 1975

    “It is a singular and notable fact that, while most other branches of science have emancipated themselves from the trammels of metaphysical reasoning, the science of geology still remains imprisoned in ‘a priori’ theories.” — Sir Henry H. Howorth, 1895

    “Science” of geology? LOL.

  21. June 24, 2008 9:17 pm

    Thank you Brian, that clears up a few things. Yeah, like you said though, I probably should have just read it myself so that I understand it all better. Will defininantly do so next time.

  22. June 24, 2008 9:27 pm

    To BrianR: I appreciate your comments and accept them in the constructive vein they were given. Since conveying information is the purpose of my comments. It’s also the goal to have clarity and suppleness. To the extent I’ve fallen short — well.

    Your tone to OilIsMastery seemed stronger than a scientific inquiry.
    But I admit to being prickly myself, due to the strong “head wind” encountered researching and commenting on this subject from geologists in general and oil geologists in particular.

    In the course of researching Abiotic Oil, I have read many dismissive articles from geologists; but what took this writer aback was the outright misrepresentations of Abiotic Theory by oil geologists in particular and even by some general geologists.

    There seemed to be a determined effort to dismiss Abiotic Oil unfairly.

    It seems geologists in general rally around oil geologists. From my research, I’m convinced the science for Abiotic Theory is solid, much more solid than given credit for in the geological community.

    Abiotic Theory embraces Cataclysm, a principle geology had rejected up until very recently. Eruptive processes can be cataclysmic — like Supervolcanoes (not all volcanoes are cataclysmic). I believe eruptive processes have had more impact on Earth’s geology than it seems, many geologists accept.

    To the extent I’ve read “hatchet job” critiques on Abiotic Theory by geologists is why I questioned geology’s objectivity in general.

    I accept Silver Fox’s statement: “Multiple working hypotheses.”

    Why? Because that means the scientific method applies. All hypotheses start at the same “starting line” and have the same burden of proof and are subject to the same level of reasonable scientific scepticism and scrutiny. Under those rules of comparison Abiotic Theory will measure up.

    Google Oil Is Mastery website to get a feeling for the extent of the science available — all direct link — and a sense of my writing on the subject.

  23. June 24, 2008 10:32 pm

    Anaconda …

    I’m done debating this with you. You are caught in an infinite loop. You demand data that backs up, as you call it – “fossil” theory, but at the same time, you cannot accept that data (e.g., a 700-page entire textbook for starters) because of a strong “belief” that it just can’t be.

    Can I give you advice? You must start collecting and analyzing data to test your theory. Until then it is conjecture and speculation. This is the main reason it is dismissed by scientists.

    If you don’t have the means to collect/analyze your own data … then put your efforts towards an actual literature review of the accepted tenets of petroleum geology. Compile real data (not opinions and rhetoric). Start a blog and address each issue rigorously and technically. The freedom of self-publishing allows you to do this.

    Perhaps I’ll address this issue myself in a future post … but I neither have the time nor the energy right now … real research takes a lot of work.

  24. June 25, 2008 12:47 am

    All the data has been collected and analyzed. The fact that oil does not come from cyanobacteria or algae or any other biological organism has been known by competent physicists, chemists, chemical engineers, and mechanical engineers since the 19th Century.

    Here is the peer reviewed science:

  25. June 25, 2008 5:31 am

    I’m just a guy wondering about a zit in the bay where I surf every day, wondering what it means for gas/oil development. But wow, as much as it was over my non-geological head, it was interesting to see you guys go at it with each other. I can’t speak much to the content, but I did feel BrianR seemed to overreact to Anaconda, taking on a an angry and demeaning tone on several posts — it didn’t seem called for to me.
    But now I want to learn more about whatever you guys are arguing about!

  26. June 25, 2008 5:51 am

    Ohhhhh… After reading a bit on the subject, I guess I can see why BrianR is a little peeved at the widely unaccepted theory being so promoted by Anaconda.

  27. June 25, 2008 6:24 am

    Ignorant … thanks for stopping by. As I said above, I apologize if my tone was perceived as over-reacting and/or angry. It is certainly not meant to be demeaning.

    I am used to lively debates with my colleagues about science … we are constantly calling each other out on each other’s writings, statements, interpretations, conclusions, etc. We are constantly challenging each other. This is what makes it strong!

    I should not assume that all non-scientists can “hear” that tone in blog comments. My bad. I can try to tell people I think they’re wrong or misguided in more polite ways. I suppose I could never be a politician :)

  28. June 25, 2008 7:23 am

    To BrianR: I was dissapointed with your response.
    It seems you want it both ways. When “your tone” is pointed out, you are contrite. But when responding to the actual critque that Abiotic Theory presents to fossil theory, you go right back to your “modus operendi.” Fine.

    Please see J.F. Kenney, Gas Resources, published in the Proceedings of the National Academy of Sciences (U.S.A.) The Evolution of Multicomponent Systems of High Pressures: VI. The Thermodynamic Stability of the Hydrogen-Carbon System: The Genesis of Hydrocarbons and the Origin of Petroleum, 2002. (available on the Oil Is Mastery website)

    This is pure science published in the most prestigous science journal in the country.

    You obviously didn’t check out the website or you wouldn’t make such an easily disproved statement.

    The website is exactly what you directed needed to be done.

    Funny, you talk about rhetoric. One of the “Fathers of Modern Geology”, Sir Charles Lyell 1797-1875 was a lawyer.

  29. June 25, 2008 7:45 am

    It’s hilarious that geologists are afraid to debate or consider peer reviewed scientific papers that contradict their religion:

  30. June 25, 2008 9:54 am

    Pursley … your attempt to paint me as dogmatic is weak … good try though, it is such a classic. An oldie, but a goodie! As I said above, I haven’t rejected the possibility of an abiotic origin of the commercial accumulations of oil on Earth … but I’m skeptical. In fact, I’m very skeptical. As a scientist, though, I must concede it’s a possibility. These ideas have not been sufficiently demonstrated to the community … if they had, we’d be applying it.

    AAPG has hosted venues for discussing this topic on at least two occasions in just the last few years (a research conference in 2005 and a technical session in 2007). So, your claim that “geologists are afraid” is also weak. But, it is an important tool in your toolbox of contrarianism, so proceed as you like.

    As for the PNAS paper, thanks for the link, I appreciate it. As a geologist, it’s admittedly a bit over my head. Perhaps I’m stubbornly wrong, perhaps you guys are right. Good luck with your theory, hope you make a lot of money.

  31. June 25, 2008 10:20 am

    Brian, I didn’t say you are dogmatic. Scientists say geology is dogmatic and I agree. But it’s not just geology, even the deans of physics are guilty. Max Plank’s generation never accepted quantum physics.

    Your extreme skepticism of abiotic alkanes and PAHs indicates to me you are suffering from this ailment as well.

    The AAPG sessions you refer to clearly prove hydrocarbons have an inorganic mantle origin. See Ivanov et al. (including Plotnikova) The Inorganic Geochemistry of Oil.

    Thanks for your kind words.

  32. June 25, 2008 10:31 am

    Pursley says: “The AAPG sessions you refer to clearly prove hydrocarbons have an inorganic mantle origin.”

    Wow … “clearly prove” … I guess it’s settled then!

    I’m very glad, I need to get back to work.

  33. June 25, 2008 10:35 am

    As for the application of abiotic theory, every oil well drilled past 15,000 feet TVD and into igneous rock is proof that abiotic petroleum origin has been demonstrated. Due to the success of this theory, Russia is now the biggest producer of petroleum in the world.

  34. June 25, 2008 10:59 am

    Pursley … your website sub-title is:

    “Abiogenic Petroleum Origin, Abiotic Oil, Inorganic Geochemistry and Petrophysics of Mantle Hydrocarbons, Mantle Oil and Volcanic Gas, Mantle Plumes, Rock Disturbances Theory of Petroleum Emanations, Astrochemistry and Astrogeology, Peak Oil Theory, And How To Profit From Them”

    Just curious … since your goal is profit (and your background is in finance), why tell everybody about this theory? Aren’t you giving away valuable information that unknown others reading your blog could profit from?

  35. June 25, 2008 11:21 am

    To BrianR:
    I can’t speak for Mr. Pursley. But my background is not finance. My motives are clear: Truth for its own sake and the quest for discovery. Man is better off with a correct understanding of the processes of the world around him.

    That is why I will continue to “offer an olive branch of peace by way of a shared quest for knowledge & understanding.”

    But I will say this: The finance of oil is best when it’s considered rare. “Fossil” theory has promoted that idea of oil.

    To suggest oil is plentiful (or more plentiful than commonly realized) goes completely against the historical grain of the oil industry.

    Could it be that there are others like me, who, regardless of their background, are also interested in knowledge for its own sake.

    If there are beneficail economic consequences, so be it.

    Scientific truth is not measured by pluses or minuses on political or economic scales.

    Keep an open mind — that’s all anybody can ask.

  36. June 25, 2008 2:58 pm

    Brian, I’m a philosopher first and a hedge fund operator second. Truth means a lot more to me than money. This means my commitment to the truth cannot be bought but lies most certainly can. Look no further than the incentive bias of petroleum geologists to convince the world hydrocarbons were only formed twice in the history of the universe. Noone even reads my blog and even if they did few people are intelligent and open minded enough to believe the science anyway.

  37. June 25, 2008 9:05 pm

    I put this message on your site … but in case you don’t see it, I’ll put it here too.

    Since you don’t have access to this particular paper, I recommend the ODP publications, they are freely available and might be useful to familiarize yourself with the kinds of measurements and analyses discussed here.

    This one is actually by the same author as the Santa Monica Basin paper, but from the Blake Ridge.

    This is the table of contents for the entire Leg 164 volume.

    And zooming out a bit more, thisis a portal to about 100 ODP leg proceedings, each with numerous chapters discussing topics you would be interested in.

    Finally, what is great about ODP is that this is essentially data available to the public. YOU can reinterpret, write, and then submit a paper … researchers do it all the time. What’s more, if for some reason you don’t like/trust the analysis, you can request samples from the core itself and do your own analysis! A LOT of researchers do this. You can fill out the sample request form here.

    This is FREE data available to interested researchers. Since you guys are both after the truth, you’ll need some data.

  38. June 25, 2008 9:16 pm

    Brian, Thank you.

  39. June 25, 2008 9:51 pm

    Yeah, thanks Brian.

  40. June 26, 2008 2:50 am

    Thank you Brian…=)

  41. October 14, 2008 8:15 am

    How much methane gas will belch if this zit pops? What effect will it have on local life under and above the seabed, and nearby land.

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