Deep-sea vents could offer a non-biological source of oil and gas.D. KELLEY & M. ELEND, UNIV. WASHINGTON INST. FOR EXPLORATION/URI-IAO/NOAA/THE LOST CITY SCIENCE TEAM
Posted on 01/31/2008 9:42:53 PM PST by neverdem
Hydrocarbons bubble up from the mid-Atlantic's Lost City.
Deep-sea vents could offer a non-biological source of oil and gas.D. KELLEY & M. ELEND, UNIV. WASHINGTON INST. FOR EXPLORATION/URI-IAO/NOAA/THE LOST CITY SCIENCE TEAM
Undersea thermal vents can yield unexpected bounty: natural gas and the building blocks of oil products. In a new analysis of Lost City, a hydrothermal field in the mid-Atlantic, researchers have found that these organic molecules are being created through inorganic processes, rather than the more typical decomposition of once-living material.
Most of the planet's oil and natural gas deposits were created when decomposing biological matter is 'cooked' in high temperatures underground. But non-biological hydrocarbons have also been found deep inside the Earth, where chemical processes create the molecules from inorganic sources such as rock.
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,” says Giora Proskurowski of the Woods Hole Oceanographic Institution in Massachusetts, one of the researchers who made the discovery.
The Lost City hydrothermal vents, some of which are 60 metres tall, sit above magnesium- and iron-rich deposits called 'ultramafic' rock. 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.
In 2003, Proskurowski and his team descended 800 metres under the waves to collect the liquid bubbling from these vents. The team returned in 2005 with a remotely operated submarine to collect more samples. By analysing carbon isotopes in the hydrocarbons they brought back, the team found that the carbon and hydrogen atoms in the molecules seemed to come from Earth’s mantle and not from biological matter that had settled on the ocean floor. The results of the study are published this week in the journal Science 1.
Bubbling crude Sampling fluids at this depth under the sea can be tricky; collecting just 150 millilitres of fluid requires a container surrounded by more than 9 kilograms of titanium to prevent depressurization, says Proskurowski.
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. Although the concentrations were too low to detect without a filter, small amounts of larger hydrocarbons such as kerosene and octane may also be produced.
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.
“There was always some nagging doubt that there could be some biological contribution such as decomposing organic matter,” says Tom McCollom of the Laboratory for Atmospheric and Space Physics at the University of Colorado at Boulder. “This really provides a means of clearing up that uncertainty.”
At this point, McCollom adds, no one knows how many hydrocarbon sources there are in the deep sea, but the types of rocks found in Lost City are widespread in other ocean regions, suggesting that it may be a common phenomenon.
The Deep, Hot Biosphere
by Thomas Gold
foreword by Freeman Dyson
1992 paper
Petroleum is just Carbon and Hydrogen (with a few elements occasionally making up another 1%.)
Anytime you get Carbon and Hydrogen mixed together in sufficient quantity, cooked up under pressure and heat over a sufficent time, you will get pretroleum and natural gas.
There are probably different modes of this occuring.
bmflr
Robots take scientists into sea depths
Seattle Post-Intelligencer | 7/29/05 | Tom Paulson
Posted on 08/02/2005 3:42:11 PM EDT by LibWhacker
http://www.freerepublic.com/focus/f-news/1455539/posts
one result of the search:
Study shows that hydrothermal vents release mercury
http://www.eurekalert.org/pub_releases/1999-10/NS-Ssth-061099.php
The magical properties of Mercury, the metal the EU wants to ban
Daily Mail (U.K.) | 6-7-07 | Michael Hanlon
Posted on 06/25/2007 9:29:40 AM EDT by Renfield
Fehttp://www.freerepublic.com/focus/news/1855857/posts
and debeers tells us diamons are rare.
Thinking that the earth doesn’t make it’s own hydrocarbons is to put tape over your telescope. We see it made by non-living forces in our own solar system. But the earth is running out. Strange.
***I often thought there was too much crude oil to be accounted for by biological deterioration of dinosaurs. Once we understand the process and catalyze it, we can say bye bye to OPEC.
Fascinating article!
And now they've found methane on a planet in another solar system
I think the folks calling it fossil fuels and believing in peak oil. Thanks for the link.
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Earth could hold more waterThere is already thought to be several oceans' worth of water slightly higher in the mantle, at a depth of around 400-650 km. This region is called the transition zone, as it is between the upper and the lower mantle. The lower mantle's minerals can retain about a tenth as much water as the rocks above, Murakami's team finds. But because the volume of the lower mantle is much greater than that of the transition zone, it could hold a comparable amount of water... Any hydrogen in the rocks presumably comes from trapped water, an idea that other measurements support. The researchers found more hydrogen than previous experiments had led them to expect.
by Philip Ball
8 March 2002Inner Earth May Hold More Water Than the SeasBased on what they witnessed in their lab, the researchers concluded that more water probably exists deep within the Earth than is present on Earth's surface -- as much as five times more... Murakami and his colleagues reached their conclusion based on how much water they managed to dissolve under the experiment's extreme conditions in several types of material that make up much of the lower mantle. They used heat and pressure -- 25.5 gigapascals of it, or more than 250,000 times natural atmospheric pressure at sea level -- to create four mineral compounds that exist in the lower mantle... Earth's oceans make up just 0.02 percent of the planet's total mass. T his means the vast lower mantle could contain many times more water than floats on the planet's surface.
by Ben Harder
March 7, 2002
Perhaps more importantly in the short term, abiotic creation of hydrocarbons may mean that there is much still to be found.
The key hint of this non-dinosuar/non-biologicl decay process to me has long been the depths at which ever more oil is found: Even the Grand Canyon is sterile at only 5000 feet depth. Diamond mines are sterile at that depths ... But we are to image that at 10,000 feet and 15,000 feet down (in different types of rock of course) at many locations around the world that biological residues are being compressed?
For Reference
Yes, in sedimentary basins. Some examples include the Williston Basin, Anadarko Basin, the Michigan Basin, the Wind River Basin, and the Permian Basin, just here in the US.
In some places in the US, crystalline 'basement' rock is exposed at the surface (Igneous or metamorphic rock), in others, it is over 30,000 ft. down. The rocks aren't all in a nice, neat, layer cake down there.
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