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thoth II
2009-Jul-16, 12:46 PM
I heard a discussion of abiotic oil and that struck me as nonsensical. Is it physically or chemically even possible for the earth to produce oil? (I think they were saying it came from the mantle?). To me, the earth's molecules are rather primitive, so I'll break the question in 2 parts (a) is it possible for the earth to create simple organic molecules like methane (b) is it possible for earth to produce intermediate complexity like amino acids (not the ones in primordial soup) or hydrocarbons like oil .

It seems like it would be simple to rule it out, but I don't know chemistry too well. But when they say a biotic that means without the help of biological creatures.

NEOWatcher
2009-Jul-16, 01:00 PM
Here's a lengthy discussion (http://www.bautforum.com/against-mainstream/65851-non-organic-formation-oil-natural-gas.html) on that. There's also links to some older discussions.

Basically; it sounds highly unlikely.

Glom
2009-Jul-16, 06:51 PM
Well we know hydrocarbon chains do form without life present, but all our exploration is geared towards searching for fossil fuels.

thoth II
2009-Jul-16, 07:53 PM
I read a theory that the scientists don't accept that (a) methane was created in the mantle in early earth, and this theory seems to come from Thomas Gold . They cited methane in Titan's atm. but that doesn't seem the same environment as mantle of earth (b) this methane rose to surface to create the hydrocarbons. It looks like literal only a handful of scientists promote this idea

Someone wrote that scientists currently think hydrocarbons came from microscopic life and that seems more likely, and said that hydrocarbons would be dissociated at the high temperatures deep in earth.

Jon Clarke said "The bulk of the Earth's crust is not sedimentary but igneous and metamorphic. If significant amount of petroleum were being sourced from such rocks you would more petroleum in them and escaping from them than we do. Apart from a few special cases we don't. "

I am quoting that, because that makes more sense to me than anything. If all the HC are being created by methane rising from mantle, then all types of rocks in the crust should be enriched in HC and not just the sedimentary type.

mike alexander
2009-Jul-16, 08:39 PM
There are definitely small amounts of abiotic methane, but not much at all compared to biogenic methane.

One thought I have had is that high temperature and pressure generally do not favor the growth of hydrocarbon chains. There is a 'petroleum window' of temperatures and much above 100C oil does not survive long-term. There are also chemical and isotopic markers in oil that overwhelmingly indicate a biological origin.