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Abiogenic Petroleum Origin

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posted on Apr, 7 2005 @ 08:10 PM
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peak oil is nothing more than "MANUFACTURED SCARCITY"!! an evil tool of oppression concieved by the evil and sadistic world bankers who consider your future nothing more than an exploitable commodity-- the same principle behind debeers manipulation of the diamond industry-see this Diamond reality
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Abiogenic petroleum origin
Wikipedia


The theory of abiogenic petroleum origin states that petroleum is produced by non-biological processes deep in the Earth. This stands in contrast to the more widely held view that it is created from the fossilization of ancient organic matter. According to this theory, petroleum is formed by non-biological reactions deep in the Earth's crust. The constituent precursors of petroleum (mainly methane) are commonplace and it is possible that appropriate conditions exist for oil to be formed deep within the Earth.

Although this theory has support by a large minority of geologists in Russia, where it was intensively developed in the 1950s and 1960s, it has only recently begun to receive attention in the West, where the biogenic theory is still believed by the vast majority of petroleum geologists. Although it was originally denied that abiogenic hydrocarbons exist at all on earth, this is now admitted by Western geologists. The orthodox position now is that while abiogenic hydrocarbons exist, they are not produced in commercially significant quantities, so that essentially all hydrocarbons that are extracted for use as fuel or raw materials are biogenic.

A variation of the abiogenic theory includes alteration by microbes similar to those which form the basis of the ecology around deep hydrothermal vents.

One prediction of this theory is that other planets of the Solar system or their moons have large petroleum oceans, either from hydrocarbons present at the formation of the Solar system, or subsequent chemical reactions.

That this theory is receiving increasing attention from Western geologists is indicated by the fact that the American Association of Petroleum Geologists scheduled a conference (www.mail-archive.com...@iagi.or.id/msg00802.html) to meet in Vienna in July 2004 entitled "Origin of Petroleum—Biogenic and/or Abiogenic and Its Significance in Hydrocarbon Exploration and Production". The conference had to be canceled, however, due to financial considerations. Instead, AAPG will be holding a one-day session on the topic at the June 2005 annual meeting in Calgary, Alberta. If the theory is correct, then it could greatly change future energy development.

Comparison of theories

There are two theories on the origin of carbon fuels: the biogenic theory and the abiogenic theory. The two theories have been intensely debated since the 1860s, shortly after the discovery of widespread petroleum. There are several differences between the biogenic and abiogenic theories.

Raw material

* Biogenic: remnants of buried plant and animal life.
* Abiogenic: deep carbon deposits from when the planet formed or subducted material.

Events before conversion

* Biogenic: Large quantities of plant and animal life were buried. Sediments accumulating over the material slowly compressed it and covered it. At a depth of several hundred meters, catagenesis converts it to bitumens and kerogens.
* Abiogenic: At depths of hundreds of kilometers, carbon deposits are a mixture of hydrocarbon molecules which leak upward through the crust. Much of the material becomes methane.

Conversion to petroleum and methane

* Biogenic: Catagenesis occurs as the depth of burial increases and the heat and pressure breaks down kerogens to form petroleum.
o Significant advances in the understanding of chemical processes and organic reactions and improved knowledge about the effects of heating and pressure during burial and diagenesis of organic sediments support biogenic processes.
* Abiogenic: When the material passes through temperatures at which extremophile microbes can survive some of it will be consumed and converted to heavier hydrocarbons.

Formation of coal

* Biogenic: Coal is organic material which was buried and compressed but did not undergo catagenesis into kerogens.
* Abiogenic: Coal is organic material which was filled with hydrocarbons which seeped into the deposit. This can happen on the surface, such as in a swamp with methane and petroleum seeps.

Evidence supporting abiogenic theory

Cold planetary formation

In the late 19th century it was believed that the Earth was extremely hot, possibly completely molten, during its formation. One reason for this was that a cooling, shrinking, planet was necessary in order to explain geologic changes such as mountain formation. A hot planet would have caused methane and other hydrocarbons to be outgassed and oxidized into carbon dioxide and water, thus there would be no carbon remaining under the surface. Planetary science now recognizes that formation was a relatively cool process until radioactive materials accumulate together deep in the planet.

Known hydrocarbon sources

Carbonaceous chondrite meteorites contain kerogen-like carbon and hydrocarbons. Heated under pressure, this material would release hydrocarbon fluids in addition to creating solid carbon deposits. Further, at least ten bodies in our solar system are known to contain at least traces of hydrocarbons.

Meteorite ALH84001, believed to be from Mars, contains carbonate minerals which were formed about 3.9 billion years ago. The deposits are in igneous rock. On Earth, microorganisms often create carbonates. However, the material could also have been formed by water carrying carbon dioxide, or by hot carbon-dioxide-bearing fluids.

Kerogen-like material has also been detected in interstellar clouds and dust particles around stars.

Methane not on Earth

Methane has been detected or is believed to exist in several locations of the solar system. It is believed to have been created by abiotic processes, except possibly on Mars.

* Jupiter
* Mars
* Saturn
o Iapetus
o Titan
* Neptune
o Triton
* Uranus
o Ariel
o Miranda
o Oberon
o Titania
o Umbriel
* Comet Halley
* Comet Hyakutake

In 2004, the Cassini spacecraft confirmed methane clouds and hydrocarbons on Titan, a moon of Saturn.

Traces of methane gas also are in the thin atmosphere of the Earth's Moon.

Methane has also been detected in interstellar clouds.

Unusual deposits

Hydrocarbon deposits have been found in places which are poorly explained by biogenic theory. Some oil fields are being refilled from deep sources, although this does not rule out a deep biogenic source rock. In the White Tiger field in Vietnam and many wells in Russia, oil and natural gas are being produced from granite basement rock. As this rock is believed to have no oil-producing sediments under it, the biogenic theory requires the oil to have leaked in from source rock dozens of kilometers away.

Deep microbes

Microbial life has been discovered 4.2 kilometers deep in Alaska and 5.2 kilometers deep in Sweden. Methanophile organisms have been known for some time, and recently it was found that microbial life in Yellowstone National Park is based on hydrogen metabolism. Other deep and hot extremophile organisms continue to be discovered.

Ambiguous results

Ongoing research has changed the status of some information. For example, some biomarkers which were interpreted as evidence supporting the biogenic theory have been undermined by finding similar materials in thermophilic situations which are part of abiogenic theories.

Biomarkers

Chemicals of biological origin have been found in many geologic hydrocarbon deposits. These biomarkers were believed to be from known surface sources. Due to the difficulty in culturing and sampling deep heat-loving bacteria, thermophiles, little was known of their chemistry. As more is learned of bacterial chemistry, more biomarkers seem likely to be due to bacterial action. Hopanoids, called the 'most abundant natural products on Earth', were believed to be indicators of oil derived from ferns and lichens but are now known to be created by many bacteria, including archaea. Sterane was thought to have come from processes involving surface deposits but is now known to be produced by several prokaryotes including methanotrophic proteobacteria.

Deep hot carbon sources

Carbonate lava

Carbonatites are intrusive carbonate-mineral-rich igneous rocks. Although they are deposits of carbon from an igneous source, the geology behind their creation is not understood.

Hydrothermal vents

Hydrothermal vents expel mineral-rich geothermally heated water.

* Carbon dioxide abiogenically produced from magma: As magma outgasses helium and carbon dioxide at depths less than 60 km, there should be deep carbon fluids present in areas such as oceanic ridges where the magma is able to heat surface waters.
* Microbes can create methane: Extremophile methanogens such as Methanopyrus can convert CO2 to methane.
* Methane can also be created chemically: Iron in rock can release hydrogen from water, then carbon dioxide can combine with the hydrogen to produce methane and water. University of Minnesota researchers discovered that rocks rich in chromium minerals can encourage chemical methane production, while also producing the more complex hydrocarbons ethane and propane.
* Methane and carbon dioxide may be dissolved in water which enters hydrothermal vent systems.
* Hydrothermal vents might release methane and carbon from deposits of biological origin, although this is less likely in vents at spreading oceanic ridges.

Evidence supporting biogenic theory

Biomarkers

It was once argued that the abiogenic theory does not explain the detection of various biomarkers in petroleum. Microbial consumption does not yet explain some trace chemicals found in deposits. Materials which suggest certain biological processes include tetracyclic diterpane and oleanane. Although extremophile microorganisms exist deep underground and some metabolize carbon, some of these biomarkers are only known so far to be created in surface plants. This shows that some petroleum deposits may have been in contact with ancient plant residues, though it does not show that the latter are the origin of the former. There also is evidence that low-temperature relatives of hyperthermophiles are widespread, so it is also possible for biological deposits to have been altered by low-temperature bacteria which are similar to deeper heat-loving relatives.

See also

* Fossil fuel

External links

* Fuel's Paradise (Wired) (www.wired.com...)
* The Mystery of Eugene Island 330 (Science Frontiers) (www.science-frontiers.com...)
* The Origin of Methane (and Oil) in the Crust of the Earth (Thomas Gold) (people.cornell.edu...)
* Gas Resources Corporation collection of documents (www.gasresources.net...)
* Abiotic oil debate (www.questionsquestions.net...)
* Gas Origin Theories to be Studied (American Association of Petroleum Geologists) (www.aapg.org...)
* Abiogenic formation of alkanes in the Earth's crust as a minor source for global hydrocarbon reservoirs (Nature) (www.nature.com.../nature/journal/v416/n6880/abs/416522a_fs.html)
* Geobiology @ MIT about biomarkers (eaps.mit.edu...)






 
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