<p>If it was produced over hundreds of millions of years, it must be at a very low rate, otherwise we would be up to our armpits in the stuff.</p>
<p>Unless it was consumed by bacteria, in which case the atmosphere's oxygen would be used up.</p>

CC BY-SA 4.0
2021-07-05T04:31:41.857Z
Chemical reactions can be "fast" and then stop due to the exhaustion of one of the reactants.
Rodrigo de Azevedo
CC BY-SA 4.0
2021-07-05T04:02:49.453Z
2021-07-05T04:02:49.453Z
Keith McClary
<p>One possible key is isotopic fractionation via biological processes - see <a href="https://en.wikipedia.org/wiki/C4_carbon_fixation#The_evolution_and_advantages_of_the_C4_pathway">dating the development of the C<sub>4</sub> photosynthetic pathway</a>, and specifically <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1626541/">isotopic fractionation between carbon-13 and carbon-14</a>. &delta;<sup>13</sup>C from volcanic degassing is markedly different to that from biological sources; the arguments for human involvement in climate change (see e.g. <a href="http://ipcc.ch">the IPCC</a>) rely on the changes in &delta;<sup>13</sup>C since the beginning of the Industrial Revolution: the value has shifted markedly towards that of the hydrocarbons we've been burning from its pre-Industrial value. (As for how we know atmospheric &delta;<sup>13</sup>C for CO<sub>2</sub> prior to the Industrial Revolution - the answer is polar ice cores!)</p>

<p>Thus the arguments for/against abiogenic oil rest on (1) isotopic ratios, and (2) other geochemical indicator ratios; see e.g. <a href="http://www.osti.gov/scitech/biblio/7052010">Jenden <em>et al.</em> (1993)</a>.</p>

<p><a href="http://www.sciencedirect.com/science/article/pii/S0264817210001224">H&ouml;&ouml;k <em>et al.</em> (2010)</a>, in a review of the arguments for biogenic and abiogenic formation processes, say:</p>

<blockquote>
  <p>However, theoretical studies, laboratory verification and discoveries of trace amounts of abiotic oil do not imply the existence of commercially significant deposits. [...] The lack of a clear and irrefutable success in locating abiotic petroleum in commercial quantities is problematic.</p>
</blockquote>

<p>This year, <a href="http://www.sciencedirect.com/science/article/pii/S0146638013002891">Ahmed <em>et al.</em> (2014)</a> advances the argument that Siljan Crater oil is unambiguously of biogenic origin due to the copresence of molecules of "known" organic origin (specifically terpane and sterane biomarkers). As for a definitive answer, [Wang <em>et al.</em> (2014)<a href="http://link.springer.com/article/10.1007/s11430-014-4821-8">7</a> say:</p>

<blockquote>
  <p>Whether abiotic (inorganic) process can form oil and gas resource is a difficult question that has been explored continuously by scientific community for more than a century but has not yet been solved.</p>
</blockquote>

CC BY-SA 3.0
2014-04-30T22:15:11.670Z
2014-04-30T22:15:11.670Z
kaberett
<p>We do know that complex hydrocarbons (e.g., tholins) exist in the outer Solar System. Some geologists maintain that at least some oil on Earth is of non-biological origin. The mainstream, though, tends to discount their views. Is it possible to verify the hypothesis empirically and what should we look for in geodata to have it substantiated or disproven?</p>

<geology><petroleum><geobiology>
How can the 'abiogenic oil' hypothesis be disproven?
Deer Hunter
# How can the 'abiogenic oil' hypothesis be disproven?

(Asked by: username_0 on 2014-04-30)

We do know that complex hydrocarbons (e.g., tholins) exist in the outer Solar System. Some geologists maintain that at least some oil on Earth is of non-biological origin. The mainstream, though, tends to discount their views. Is it possible to verify the hypothesis empirically and what should we look for in geodata to have it substantiated or disproven?

**Tags:** geology, petroleum, geobiology


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## 2 answers

### Answer by username_3 on 2014-04-30. Score: 10 | Accepted answer

One possible key is isotopic fractionation via biological processes - see [dating the development of the C4 photosynthetic pathway](https://en.wikipedia.org/wiki/C4_carbon_fixation#The_evolution_and_advantages_of_the_C4_pathway), and specifically [isotopic fractionation between carbon-13 and carbon-14](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1626541/). δ13C from volcanic degassing is markedly different to that from biological sources; the arguments for human involvement in climate change (see e.g. [the IPCC](http://ipcc.ch)) rely on the changes in δ13C since the beginning of the Industrial Revolution: the value has shifted markedly towards that of the hydrocarbons we've been burning from its pre-Industrial value. (As for how we know atmospheric δ13C for CO2 prior to the Industrial Revolution - the answer is polar ice cores!)

Thus the arguments for/against abiogenic oil rest on (1) isotopic ratios, and (2) other geochemical indicator ratios; see e.g. [Jenden *et al.* (1993)](http://www.osti.gov/scitech/biblio/7052010).

[Höök *et al.* (2010)](http://www.sciencedirect.com/science/article/pii/S0264817210001224), in a review of the arguments for biogenic and abiogenic formation processes, say:

> However, theoretical studies, laboratory verification and discoveries of trace amounts of abiotic oil do not imply the existence of commercially significant deposits. [...] The lack of a clear and irrefutable success in locating abiotic petroleum in commercial quantities is problematic.

This year, [Ahmed *et al.* (2014)](http://www.sciencedirect.com/science/article/pii/S0146638013002891) advances the argument that Siljan Crater oil is unambiguously of biogenic origin due to the copresence of molecules of "known" organic origin (specifically terpane and sterane biomarkers). As for a definitive answer, [Wang *et al.* (2014)[7](http://link.springer.com/article/10.1007/s11430-014-4821-8) say:

> Whether abiotic (inorganic) process can form oil and gas resource is a difficult question that has been explored continuously by scientific community for more than a century but has not yet been solved.


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### Answer by username_1 on 2021-07-05. Score: 0

If it was produced over hundreds of millions of years, it must be at a very low rate, otherwise we would be up to our armpits in the stuff.

Unless it was consumed by bacteria, in which case the atmosphere's oxygen would be used up.

> **Comments:**
> **username_2**: Chemical reactions can be "fast" and then stop due to the exhaustion of one of the reactants.  

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