A-oil vs B-oil

Cecil's Columns/Staff Reports
1

Some of Cecil’s columns have been fluff lately, but this one sure strikes a fascinating, contreversial, and extremely relevant note.

I’ll research this a bit more later, but i do have to say that i find it VERY doubtful that so much stuff could fall to the sea floor and be left there without being eaten! I think in last couple decades we have learned much more about the ecosystems sustained in the middle and the bottom of the ocean by sinking biomatter. We have also learned about the organisms that live IN the ocean floor and which presumably feed on this same stuff. I simply cannot believe that billions (trillions?) of tons of plankton would fall to the ocean floor and just be left there to turn into bioslush, even if it does get mixed up with the sediment a bit.

Surely these more recent discoveries haven’t been factored into the A-oil B-oil debate as well as they should. That, and just sheer common sense of the way life works. Rember, dinosaurs or other fossils usually had some cataclysmic thing happen to them that quickly covered and preserved them. Stuff like that doesn’t happen on the ocean floor, or at least not nearly often enough.

Of course, the biological source could be different, but the plantkon-falling-to-the-bottom theory holds zero water for me.

What I don’t understand, however, is why isn’t there some sort of test, like carbon isotope analysis, to conclusively determine whether this stuff is biological or not?

2

Common sense does not work here as billions of years are not in your common experience. To my knowledge there have been no findings about the sea floor that would invalidate existing theories. Also, your reference to the formation of fossils is inappropriate as very different processes are involved in the creation of fossils and fossil fuels.

As to a test, why would previously biologic oil have a different isotope ratio than non-biologic oil?

These questions will soon be answered by our resident expert.

3

Common sense does work here, as my common sense is based on my knowledge of biology and not my personal experience. Stuff isn’t just going to lie around the seafloor and not get eaten. Life invades EVERY corner that has sustenance, so common sense says that unless you have an excellent explanation for how this dead stuff could have been effectively sterilized and sealed, it’s going to get eaten.

And also, for a long time people did think that the seafloor was mostly barren and there’s been many discoveries lately about how in fact it is far from it. Moreover, we now believe that life there is sustained precisely by sinking debris. (And i guess before we’d just assumed it fell and turned to oil).

You’re right that fossils might not be to the point, but soft fossils (ie stuff that’s made of carbon and not minerals) are to the point. They are very rare because it is very rare that stuff lies around and doesn’t get eaten. Something very special has to happen to preserve it.
Regarding isotopes: Haven’t you ever heard of carbon-14 dating? I mean it doesn’t apply here (carbon-14 decays too fast), but it’s perfectly reasonable to expect that there might be some other isotope that could be used, or some other chemical signature that could be employed. Obviously nothing conclusive has come out, but maybe there is partial evidence one way or another.

4

And the column being discussed is Did oil really come from dinosaurs?

5

If the bottom of the sea/lake was anoxic (low oxygen) decay occurs very slowly, allowing biomass to build up. The lower reaches of the Black sea are like that - wooden ships that sank there are still well preserved because nothing can live there to eat it. Then conditions change and sedimentary layers build up on top of the biomass - and voila - oil. And evidence suggests some very steady states - 6 million annual layers in the Green River system.

We are talking about hydrocarbons - hydrogen and carbon. No long-lived isotopes there, so no clues about origins. We know as much as there is to know about the makeup of crude oil and the geological material around it - the petrochemical industry has to know this to make money - so there is nothing more to look for in terms of evidence.

But … the abiotic process requires serious strongly reducing conditions - maybe hydrides plus carbonates to give hydrocarbons and oxides - which are more extreme than the biomass conversion to oil. We don’t observe these conditions. I agree that more and deeper investigations may provide more evidence, but if there was any evidence the oil companies would be on it like a shot - they would prefer to drill deeper to find abiotic oil sources than to have to extract oil in places like Nigeria, the North Sea, Alaska, Iraq etc. If local geology had nothing to do with oil location, there would be no geopolitical issues to deal with, and oil companies are pragmatists with an eye on the bottom line.

Simon

6

I’m miffed about this column because I’d asked a similar question almost 4 years ago in GQ and Cecil didn’t bother to respond. Grrr.

7

Even if stuff did get eaten, how would that change anything? So a sea-floor critter eats the sunken plankton. What happens then? Eventually, that critter that ate it dies, too. What you would need to invalidate the theory is some mechanism for transporting organic material back to the surface, and just eating won’t necessarily do that.

8

Reading the wiki page on abiogentic pertroleum (yeah, yeah, i know, wiki. my defence is that every single other source is up to the ears with bullshit too, and if you want authority you need to read them all. Plus, Google sure’s gotten crappy lately.)

There is plenty of chemical/isotope evidence. I don’t know why you guys thought there wouldn’t be. Some of this evidence points in the direction of biologic origin. There are “biomarkers” present in the oil, and things like the isotope ratio of Helium point to crustal (as opposed to mantle) origin. However, other evidence, such as the abundance of trace metals often found in the mantle, point to a-oil. Oil also supposedly has far too few unsaturated fats (too much hydrogen) than can be expected of life. An analysis of trace metals in 77 differently sourced oils correlates significantly better with the primitive mantle and the abiogenic processes than with oceanic or continental crust, and does not correlate with seawater at all.

I’m still finding it a bit hard to believe the unconsumed-leftovers theory (especially in light of this evidence from the metal analysis). Even in anoxic waters, you can still have plenty of life. Wood might not get eaten because it’s particularly tough and made of a substance that ocean dwellers aren’t familiar with. However, if the ocean floor was full of wood, I’ll bet you there’ll evolve a lifeform to eat it.

A rather interesting theory brought up in that article is that the origin of oil may be biological but stems not from uneaten algea but from the excrement of the crustal biosphere. The more difficult part in the abiogenic oil theory is the mechanism which would have produced all that methane to then convert to longer hydrocarbons. However, we have recently begun to realize more and more (especially within the past five years) how there exists microbial life reaching for kilometers into the crust that does little else but churn out methane. Much of that methane supposedly gets eaten by crustal life that resides closer to the surface, while more gets turned to hydrites. However, I think it would make a lot of sense if a great deal of it got turned to oil. This is one of those theories that is so new that I think it simply hasn’t received a proper consideration yet.

9

Oh, P.S., of course getting eaten changes things. In the presence of oxygen, all that results is carbon dioxide. I guess without oxygen there’s less leeway, but your examples of anoxic waters are special cases and don’t apply to the continental shelfs and other supposed locales of biomass accumulation. Oh, and the eaters get eaten by other eaters, of course. They would never be let to accumulate dead. You also don’t need to transport anything back to the surface except energy (in the form of heat)… since it’s energy not carbon that matters. What a silly thought.

10

er, not “your examples” but blakely’s examples. god, i wish there was an edit button.

11

I too asked a similar question almost four years ago And Cecil ignored me too. :frowning:

12

That thread linked to in the last post contained a cite to an Economist article on this issue. It doesn’t really say anything substantive, and it doesn’t argue for my hypothesis that it’s the crustal biosphere that’s involved, but I suppose people may be interested in reading it anyway. I’ve got a subscription, so I am able to access it. And no, I do not wish to recognize the copyright laws which seek to deprive us of this sharing of knowledge.

13

Tuckerfan and Khadaji:
Cecil didn’t ignore you. It just took him four years to adequately research & craft a perfect response. An off-the-cuff two- or three-year response just isn’t sufficient to produce the kind of quality we’ve come to expect from Mr. Adams …

14

You may not take copyright law seriously, but we at the Straight Dope do. I have deleted the bulk of the copied material. In the future, do not quote more than a paragraph or two of copyrighted material.

bibliophage
moderator CCC

15

But it does: [ur=“http://equake.geos.vt.edu/acourses/3034/000423-WP_ballardbook.html”]The third paragraph down in this link briefly describes a famous incident in which some easily accessible food sank to the sea floor and suffered little for its trouble over almost a year.

Have you ever seen abundance estimates for the ocean floor? See the first paragraph under II. in this link. There really isn’t a huge number of individuals down there (with the exception of bacteria and archea, which recent discoveries have shown are far more abundant than was previously believed), and we’ve learned a lot about rare systems such as hydrothermal vents and whale falls. To be sure, there are a deposit feeders, but they’re few and far between in the vastness of the sea. Here is more of a primary source describing how little of the material sinking from the photic zone (where phytoplankton have sufficient light to add to their net biomass) leads to metabolisation on the sea floor. Even if it was all eaten what would prevent the benthic organisms themselves from becoming sequestered carbon and eventually fossil fuels? :confused:

Of course, we don’t need to go to the lengths of internal contradiction to see evidence that organic matter is incompletely digested. In an incredibly more accessible environment, coastal marshes, vast amounts of organic matter are preserved. With orders of magnitude more deposit feeders.

Pray tell what discoveries you’re talking about. Nothing I’ve seen in the last few years has convinced me that the deep sea has high abundance of organisms. You may be talking about the most exciting discoveries: of hydrothemal vents and whale fall communities, but those are exciting specifically because they’re rare.

No offense, but I’m going to ask for evidence that organic matter doesn’t build up in the deep sea. That’s been well-established in oceanography for decades, and no discoveries contradicting that have come to light. I’ve linked to evidence that it does above, and if that’s not enough, here’s some more, and here (warning: PDF), and a very relevant article describing an upwards revision of the amount of organic carbon sequestered in the deep sea [here](http://links.jstor.org/sici?sici=0024-3590(200009)45%3A6<1245%3AIDOC(C>2.0.CO%3B2-N#abstract).
I don’t know the ins and outs of geology to describe biogenic or abiogenic origins of oil, but it’s hogwash to doubt it because you don’t think organic matter builds up on the sea floor: the consensus is quite clearly that it does.

16

I’m pretty sure there’s no distinction in the law between copying a few paragraphs and copying the whole thing. A couple sentences with direct appended comments is probably allowed explicitly in the law, but i’m pretty sure there’s no difference between copying a quarter of an article and all of it.
Anyway, no one’s ever gonna sue anyone for something like this, so why are you concerned? Most importantly, why are you taking a moralist stance? Nowhere in the bible does it say “Thou shall not use someone’s words without expressed written permission.” Hell, I’ll bet Jesus would have thrown up at the very idea. Copyrights are something people came together and set down for practical reasons (and hundreds of years ago, no less). Therefore, we should always evaluate them in practical terms and with an open mind. How can you possibly support informational feudalism in such a case of overwhelming educational merit? Do you think teachers ought be barred from xeroxing such articles for their students as well? (I mean they’re already barred, but would you think it right to enforce that?)

The Economist is making money just fine with or without me and everyone else copying their articles for this purpose. In fact, it is only because my teacher would hand me Economist articles that I actually went out and bought a subscription.

So stfu with your uncle tomming of this oppresive legislation.

anyway, back to the topic…

But those are exactly the organisms that tend to be decomposers.

You linked to a paper. Honestly, I don’t understand what it says. However,
“The benthic reaction to POM pulses was quite diverse. The mega-, macro- and meiobenthos showed no change in biomass, whereas bacterial biomass doubled between March and July.” and " Bacteria and protozoans colonizing the epibenthic phytodetrital layer were responsible for 60-80% of the seasonal increase in SCOC. The strong reaction of the smaller benthic size groups (bacteria, protozoans) to POM pulses stresses their particular importance for sediment-water interface flux rates."
I think has as good a chance, or better, of supporting my point than yours.

Sigh, come on, are you seriously arguing that? That’s like asking why decomposers don’t just pile up into huge mounds in soil. However, you did mention carbon specifically. Like i said previously, the key characteristic of fossil fuels isn’t carbon, it’s energy. The carbon itself might as well stay on the ocean floor (although many low-energy compounds, like carbon dioxide, will desolve). However, it would not be able to turn into anything useful in that form.

But… you… just… said…

bro… take a breather

Regarding your links at the bottom. The first one doesn’t work. The second doesn’t talk about the ocean floor but rather its phtosynthetic layer. The third talks about how much carbon (admittedly in an energy-rich state) is FALLING to the floor, not what happens to it once it arrives.

No, quite clearly there is no such consus. Or at least, you have definately not demonstrated one and neither has anyone else. If anything, you AGREEED EXPLICITLY with my assertion that we’ve been underestimating the amount of organisms living in the mud, eating the stuff that falls down.

17

Oh, I apologize for forgetting to comment on what would potentially be your most potent argument against me… that 11-month-old uneaten lunch aboard Alvin.

Firstly, its composition is surely quite alien to the inhabitants of the deep sea. Secondly, as the article itself pointed out, our commercial food is rich in preservatives. Thirdly, no one posited a timescale for how long decomposition may take in that ecosystem.

Lastly, and most importantly, the decomposers live in the mud. They do not so much swim around in the water. They eat what sinks not floats, after all.

18

The Straight Dope and the Chicago Reader, dependent as they are on intellectual property rights, takes those rights more seriously than many other Internet sites. I don’t know that there is any hard and fast rule about what percentage of a copyrighted article can be copied and remain fair use under the law. I figure one paragraph probably is fair use. Clearly copying the whole thing without permission is not. Whether the Economist is making money or not is immaterial. If you don’t have permission to copy the whole thing, you can’t copy the whole thing. Failure to heed our rules may result in your losing your posting privileges.

The BBQ Pit forum is the forum for complaining about board rules or moderator actions. The Great Debates forum is the forum for debating laws.

bibliophage
moderator CCC

19

I’m pretty sure there is in fact a distinction. I got this impression by consulting Title 17 of the United States Code:

(Emphasis added).

20

wait… so the law explicitly corrobates nearly everything that I was arguing for on merely wistful grounds. (thanks, gfactor)

It DOES protect the copying of works for educational and scholarly purposes, as i beseeched.

It DOES consider the monetary issues, so my argument that my act will, if anything, probably boost subscriptions IS extremely to the point.

The nature of the work in question I would assume also qualifies for exemption quite well.

The amount does, however, apprently play a role. It is not made clear to what degree, and it is only one criterion out of four. It is also placed third in importance.
So anyway, bibliophage, stop your bsing about copyrights, you oppresive [something]. You are on shaky terms even when sticking to the letter of the law, and anyone will see that you are certainly not doing the world as a whole any good.

The straight dope is about fighting ignorance! You would rather it remain, if only you can earn on it a penny.