Deep-ocean vents found to be source of oil and natural gasFebruary 1st, 2008 - 4:59 pm ICT by admin
Washington, Feb 1 (ANI): A new research has indicated that undersea vents are a non-biological source of oil and natural gas.
According to a report in Nature News, the analysis was made by researchers in Lost City, a hydrothermal field in the mid-Atlantic.
Here, the researchers found organic molecules in hydrothermal vents, which are being created through organic processes, rather than the more typical decomposition of once-living material.
The Lost City hydrothermal vents, some of which are 60 metres tall, sit above magnesium- and iron-rich deposits called ‘ultramafic’ rock, the report said.
The minerals contained in the rocks interact with water to produce an environment with plentiful hydrogen, making it chemically favourable for the creation of the hydrocarbon molecules that make up oil and gas, it added.
Although researchers have seen some evidence for inorganic production of hydrogen in the ocean, Lost City is the first really clear example of a marine, deep-sea world where hydrocarbons are being synthesized abiotically, said Giora Proskurowski of the Woods Hole Oceanographic Institution in Massachusetts, one of the researchers who made the discovery.
To rule out the possibility that the hydrocarbons collected from the vents were created from biological material, the team analysed several different isotopes.
Among other measurements, the team analysed the amount of carbon-13 in methane, which contains one carbon atom, and in hydrocarbons containing two, three, and four carbon atoms. As the number of carbon atoms rose, the concentration of carbon-13 fell the opposite trend to that seen in biologically derived hydrocarbons.
Instead, the pattern of isotopes suggest that a chemical process called the Fischer-Tropsch process is at work in Lost City, creating bigger and bigger hydrocarbons in the hydrogen-rich environment.
The team also found that the methane in Lost City contained no carbon-14, suggesting the carbon source for the hydrocarbons comes from within the mantle, far away from organisms that might have had contact with the global carbon cycle at the surface. (ANI)
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