Hokulele
Deleterious Slab of Damnation
Thanks Tricky! One question, how common is it for petroleum products to surface? Would La Brea tar pits be an example of this?
Nyet. The organic stuff must have an organic source idea was knocked out in 1828.
If you want a really clear example of a organic molicule with no life based source look at the long chain carbon stuff you get turning up in the other layer of stars.
I'm not choosing sides, but it has been done in the lab without organic sources.
http://www.pnas.org/cgi/content/abstract/0405930101v1?view=abstract
I heard or watched a presentation about two years ago by Henry Scott on the experiment. It was quite intriguing.
Okay, end of lesson. I'll be happy to answer specific questions to the best of my ability.
I wasn't talking stars, geni. Tell me, is there carbon in petroleum?
If so, where does it come from?
Let's pretend for the moment that methane is not considered a part of petroleum and that there are no stars in the Earth's mantle. Would you just do that for a teensy moment?
Okay, why do you consider carbonates inorganic?
Okay, why do you consider carbonates inorganic?
As much as it pains me to disagree with you Slimething (I always enjoy your posts), I do want to clarify something here. Organic/inorganic in chemistry does not necessarily mean having an origin in organic life. My mother has a PhD in organic chemistry, and I have had to listen to waaaaay too many discussions about what the term organic chemistry means.
CaCO3? No carbon carbon bonds
Disagree all you want. Organic chemistry does not limit itself to carbon compounds that originate from biological processes. Organic chemistry has to do with carbon. Put your mother on.
As to inorganic hydrocarbon compounds, yes, they happen. There is a lot of non-organic carbon in the earth and a lot of "laboratories" where heat and pressure can do odd things. The abiogenic theory of petroleum formation had it's most fervent adherent in Thomas Gold, and he convince enough others to actually try some drilling tests. The most famous of these tests was the drilling project at the Siljan Ring, an ancient meteorite impact area. A few complex hydrocarbons were found which did appear to have inorganic origin (at least partially), but not in anything close to economic quantities. However, it is widely accepted that the vast majority of complex organic compounds (greater than two carbons) are produced by organic activities. The evidence is simply overwhelming.
On the other hand, "organic" in petroleum geology does mean originating from life. And you're not asking chemistry questions here....
Here's the relevant paragraph from Tricky. Note the use of "inorganic," "non-organic," and "abiogenic" as synonyms.
I wasn't aware that the term "organic" varied that significantly between chemistry and geology. So, I apologize for the confusion.
If you think that "organic" simply means "carbon-containing," then the statement that "there is a lot of non-organic carbon in the earth" is not only false, but paradoxically oxymoronic.
No, I don't believe that at all. There are some intersting carbon-containing compounds that are strictly considered inorganic. An example is calcium carbide. The reason they're considered inorganic is because the bonding in them is ionic, not covalent*, as in organic compounds. Said calcium carbide is interesting in that, when moistened, it gives off acetylene, definitely an organic compound.
Sorry to be tiresome and pendantic but, chemistry-wise, carbonates are organic but some are abiotic in origin.
*Sorry, no bright line between ionic and covalent bonding either.
Disagree all you want. Organic chemistry does not limit itself to carbon compounds that originate from biological processes. Organic chemistry has to do with carbon. Put your mother on.
ETA: Hokulele, I hope the fact that I'm wrong occassionally does not put you off to my posts. However, carbonates being inorganic is a prevailing myth that I've had to debunk to a fair number of students. So, I can't let this one slide. I think your mother would understand.
Quite common, but the volumes vary tremendously. Methane, being a small molecule, is seeping out almost continuously, along with other lighter molecules. Tar pits are somewhat less common, but often when you see tar, there are actually lots of lighter hydrocarbons that you can't see.Thanks Tricky! One question, how common is it for petroleum products to surface? Would La Brea tar pits be an example of this?
It is simply because of the definition of "organic" used by most chemists. Organic means compounds containing carbon, hydrogen and oxygen. Since CaCO3 doesn't have hydrogen, it is not considered "organic" from a chemical standpoint.Okay, why do you consider carbonates inorganic?
Not just carbon. Carbon, hydrogen and oxygen. Diamonds, for example, are not considered organic, even though the carbon they are created from may have once been part of an organism.Disagree all you want. Organic chemistry does not limit itself to carbon compounds that originate from biological processes. Organic chemistry has to do with carbon. Put your mother on.
There's been some astronomy talk in this thread also. Someone should introduce the word "metal" in to this conversation.On the other hand, "organic" in petroleum geology does mean originating from life. And you're not asking chemistry questions here....
It is simply because of the definition of "organic" used by most chemists. Organic means compounds containing carbon, hydrogen and oxygen. Since CaCO3 doesn't have hydrogen, it is not considered "organic" from a chemical standpoint.
I know it seems odd, but organic, in the chemical sense, doesn't mean "arising from life". Instead, chemists use the word "biogenic" for such compounds.

pray that the Blessed St Ignatius Of The Bleedin' Obvious will vouchsafe you a vision of Carboniferous fossils.