What may be the largest source of abiotic methane gas on Earth

Posted: November 29, 2022 by oldbrew in Geology, research

Natural gas flare [credit: Wikipedia]

abiotic — Not associated with or derived from living organisms. Calling methane, aka natural gas, a ‘fossil fuel’ is shown by geological evidence to be inaccurate.
– – –
Methane (CH4), the chief constituent of natural gas, is one of the most widely used “clean” fuels, says Phys.org.

Although methane is usually considered to originate from organic matter, recently, more and more evidence shows that methane can be produced by abiotic processes.

In a recent paper published in National Science Review (NSR), Professor Lifei Zhang’s team from Peking University demonstrated that large amounts of methane gas can form during prograde metamorphism in a cold subduction zone, evidenced by the massive CH4-rich fluid inclusions in eclogites from Western Tianshan, China.

Based on their calculation, the potential CH4 flux from worldwide modern subduction zones is estimated to be as much as ~10.8 Mt/y.

Consequently, the subducted cold oceanic crust may produce the largest amount of abiotic methane, along with other abiotic methane sources such as that from mid-ocean ridges or that from high-pressure serpentinization.

Massive CH4-rich fluid inclusions have been found in garnet and omphcite, which are the main constituent minerals of eclogite in the West Tianshan subduction zone (eclogite is the most important high grade metamorphic rock during cold subduction).

Isotopic analyses and petrological studies both demonstrated that this methane was of abiotic origin and formed by water-rocks reactions during the prograde high-pressure to ultrahigh-pressure metamorphism.

Full article here.
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JOURNAL ARTICLE — Massive abiotic methane production in eclogite during cold subduction

  1. Bloke down the pub says:

    Wouldn’t rock that is subducted still include organic material from the sea bed?

  2. tallbloke says:

  3. Philip Mulholland says:

    Calling methane, aka natural gas, a ‘fossil fuel’ is shown by geological evidence to be inaccurate.

    It’s all about political framing. Stop playing the destroyers’ game. From now on use the term “mineral fuel” as an accurate descriptor for all of these vital mineral resources.

  4. […] What may be the largest source of abiotic methane gas on Earth — Tallbloke’s Talkshop […]

  5. JB says:

    Russian geologists in the 50s figured out that the earth made oil and gas naturally. This is not new. What may be new is where they’re finding it and the local process.

    I’ve always said there’s no such thing as “fossil” fuel–unless a process has been developed to crush them into flammable vapor. Even as a kid I recognized the TV adds about oil and gas being a product of organic, decayed life, such as the dinosaurs touted by Sinclair and Standard oil companies was baloney.

  6. oldbrew says:

    It may not be accessible any time soon, or at all, as China just signed a 27-year gas mega-deal with Qatar.


  7. Peter Norman says:

    Oh! This is such exciting news. China has a new source of methane. Let’s negotiate a contract to import it to reduce UK household heating costs. Hang on. There are millions of cubic meters of the stuff in our own UK underground fossil reserves. Nasty UK fossil fuel? Can’t go there!

  8. Gamecock says:

    Let me unpack this.

    ‘Although methane is usually considered to originate from organic matter’

    ‘Organic matter’ is matter containing carbon. Methane contains carbon. ∴ methane
    MUST come from organic matter.

    ‘recently, more and more evidence shows that methane can be produced by abiotic processes.’

    Methane is ubiquitous in the solar system. We can presume it is abiotic outside the earth. ‘recently, more and more evidence’ is NOT in Prof Zhang’s paper. It is claptrap introduced by phys.org’s talented writers.

    I have no reason to doubt Professor Lifei Zhang’s findings. It is even good news to know that there are mechanisms currently producing more methane.

    But I would note that the earth may contain massive amounts of residual methane from its origins, as with other planetary bodies and their moons.

  9. Gamecock says:

    “Russian geologists in the 50s figured out that the earth made oil and gas naturally.”

    Absolutely false on oil. Abiotic oil is utterly disproven by stereo chemistry.

  10. Ned Nikolov, Ph.D. says:

    It does not take much brain power to figure out that methane (CH4) can also have abiotic origin. One only has to look at Titan, a moon of Neptune Saturn, which hosts methane lakes that are larger than the Great Lakes in Northeast America. Titan is estimated to have “hundreds of times more natural gas and other liquid hydrocarbons than all the known oil and natural gas reserves on Earth“:


    My guess is that most methane on Earth is likely of abiotic origin.

    amended as shown [mod]

  11. Graeme No.2 says:

    So to get out of their self induced economic mess (depression and blackouts) all the EU has to do is build a fleet of tankers to bring methane back from Titan.
    Catch 23: Their factories are shut down from lack of methane.

  12. Ned, slight slip up we all do it. Titan is a moon of Saturn with CH4 in the atmosphere as you say (see https://solarsystem.nasa.gov/moons/saturn-moons/titan/in-depth/). It is Triton that is a moon of Neptune

  13. oldbrew says:

    From a Wikipedia link…

    Fossils From Animals And Plants Are Not Necessary For Crude Oil And Natural Gas, Swedish Researchers Find
    Date: September 12, 2009
    Source: Vetenskapsrådet (The Swedish Research Council)

    Researchers in Sweden have managed to prove that fossils from animals and plants are not necessary for crude oil and natural gas to be generated. The findings are revolutionary since this means, on the one hand, that it will be much easier to find these sources of energy and, on the other hand, that they can be found all over the globe.
    . . .
    According to Vladimir Kutcherov, the findings are a clear indication that the oil supply is not about to end, which researchers and experts in the field have long feared.

    He adds that there is no way that fossil oil, with the help of gravity or other forces, could have seeped down to a depth of 10.5 kilometers in the state of Texas, for example, which is rich in oil deposits.


  14. Gamecock says:

    “According to Vladimir Kutcherov, the findings are a clear indication that the oil supply is not about to end”

    Not so fast. We are talking about methane, not oil. It is possible oil is formed from methane, but it is a biological process (proven by stereo chemistry). We do not know what that process is, nor do we know if it still operates (microbes go extinct).

  15. oldbrew says:

    There’s syngas, Fischer-Tropf process and the like.

    What exactly goes on deep inside the Earth is another matter of course. Methane clathrate on the seabed is an interesting one…

    Originally thought to occur only in the outer regions of the Solar System, where temperatures are low and water ice is common, significant deposits of methane clathrate have been found under sediments on the ocean floors of the Earth.[6] Methane hydrate is formed when hydrogen-bonded water and methane gas come into contact at high pressures and low temperatures in oceans.
    . . .
    Methane hydrates are believed to form by the precipitation or crystallisation of methane migrating from deep along geological faults.


    Then there’s the Clathrate gun hypothesis, ‘no longer considered relevant for the near future climate change’…
    – – –
    ‘Originally thought to occur only in the outer regions of the Solar System’ — out of range for current human observation, like the origin of water and anything else there’s no slam-dunk explanation for.

    Going back far enough there were no ‘outer regions of the Solar System’, maybe no regions either 🤔

  16. catweazle666 says:

    “Methane hydrates are believed to form by the precipitation or crystallisation of methane migrating from deep along geological faults.”

    How about the decomposition of organic matter?

    That would explain its existence in huge quantities in the permafrost as well.

  17. Ned Nikolov, Ph.D. says:


    Correct, Titan is a moon of Saturn, not Neptune. Sorry for the funny typo… 🙂

  18. Ned Nikolov, Ph.D. says:


    Yes, indeed! Most oil and natural gas on Earth has abiotic origin, and as such they are “renewable resources”, and not “fossil fuels”:


    Russian geologists knew this 55 years ago!

  19. Ned Nikolov, Ph.D. says:

    Note that all authors of this 2009 paper discussing the abiotic origin of oil and gas are Russians:


  20. Gamecock says:

    Dr Ned, take an organic chemistry course. Abiotic oil is stupid false.

  21. Gamecock your comment is rude. I am a registered Chemical engineer. There is abiotic oil. There are also bacteria that can make oil from plants but there is no proof that large oil deposits have a fossil origin. That was false information put out in the late 19th century by some producers in USA. There is much evidence that large oil deposits are associated with areas of subduction zones (both recent and in past). There is some natural gas on land in the centre of Australia but there is oil in the seas around the land associated with the Australian plate. There is oil and gas adjacent to the ring of fire Indonesia, Malaysia, Borneo, Burma and the Chinese are interested in the potential oil in the seas off Vietnam where they are claiming the Spratley Islands. The large oil and gas deposits in the middle east maybe related to the north edge of the African plate where there is still volcanic activity. Did you know that the Egyptians were using bitumen around 3000BC?

  22. oldbrew says:

    Methane-rich Titan in the news…

    Saturn’s largest moon is the only one in the solar system found to have seasonal weather patterns: James Webb spots large clouds on Titan that appear in the late summertime
    1 December 2022

    ‘Scientists say this proves computer model predictions that Titan has seasonal weather patterns’


    More details from NASA…

    ‘We had waited for years to use Webb’s infrared vision to study Titan’s atmosphere, including its fascinating weather patterns and gaseous composition, and also see through the haze to study albedo features (bright and dark patches) on the surface. Titan’s atmosphere is incredibly interesting, not only due to its methane clouds and storms, but also because of what it can tell us about Titan’s past and future – including whether it always had an atmosphere. We were absolutely delighted with the initial results.’


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