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snoot
look alive ∞




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a rock found being 250million years then the oldest rock known.
#8991909 - 09/26/08 11:51 PM (15 years, 7 months ago) |
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this is intense, this rock being 250,000,000 years older then the oldest rock known before it. http://news.bbc.co.uk/2/hi/science/nature/7639024.stm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Team finds Earth's 'oldest rocks'
By James Morgan Science reporter, BBC News
The rocks contain structures which might indicate life was present Earth's most ancient rocks, with an age of 4.28 billion years, have been found on the shore of Hudson Bay, Canada. Writing in Science journal, a team reports finding that a sample of Nuvvuagittuq greenstone is 250 million years older than any rocks known. It may even hold evidence of activity by ancient life forms. If so, it would be the earliest evidence of life on Earth - but co-author Don Francis cautioned that this had not been established. "The rocks contain a very special chemical signature - one that can only be found in rocks which are very, very old," he said. The professor of geology, who is based at McGill University in Montreal, added: "Nobody has found that signal any place else on the Earth." "Originally, we thought the rocks were maybe 3.8 billion years old.
The exciting thing is that we've seen a chemical signature that's never been seen before

Prof Don Francis, McGill University
"Now we have pushed the Earth's crust back by hundreds of millions of years. That's why everyone is so excited." Ancient rocks act as a time capsule - offering chemical clues to help geologists solve longstanding riddles of how the Earth formed and how life arose on it. But the majority of our planet's early crust has already been mashed and recycled into Earth's interior several times over by plate tectonics. Before this study, the oldest whole rocks were from a 4.03 billion-year-old body known as the Acasta Gneiss, in Canada's Northwest Territories. The only things known to be older are mineral grains called zircons from Western Australia, which date back 4.36 billion years. Date range Professor Francis was looking for clues to the nature of the Earth's mantle 3.8 billion years ago. He and colleague Jonathan O'Neil, from McGill University, travelled to remote tundra on the eastern shore of Hudson Bay, in northern Quebec, to examine an outcrop of the Nuvvuagittuq greenstone belt.
The rocks turned out to be far older than first thought They sent samples for chemical analysis to scientists at the Carnegie Institution of Washington, who dated the rocks by measuring isotopes of the rare earth elements neodymium and samarium, which decay over time at a known rate. The oldest rocks, termed "faux amphibolite", were dated within the range from 3.8 to 4.28 billion years old. "4.28 billion is the figure I favour," says Francis. "It could be that the rock was formed 4.3 billion years ago, but then it was re-worked into another rock form 3.8bn years ago. That's a hard distinction to draw." The same unit of rock contains geological structures which might only have been formed if early life forms were present on the planet, Professor Francis suggested. Early habitat? The material displays a banded iron formation - fine ribbon-like bands of alternating magnetite and quartz. This feature is typical of rock precipitated in deep sea hydrothermal vents - which have been touted as potential habitats for early life on Earth. "These ribbons could imply that 4.3 billion years ago, Earth had an ocean, with hydrothermal circulation," said Francis. "Now, some people believe that to make precipitation work, you also need bacteria. "If that were true, then this would be the oldest evidence of life. "But if I were to say that, people would yell and scream and say that there is no hard evidence." Fortunately, geologists have already begun looking for such evidence, in similar rocks found in Greenland, dated 3.8 billion years. "The great thing about our find, is it will bring in people here to Lake Hudson to carry out specialised studies and see whether there was life here or not," says Francis. "Regardless of that, or the exact date of the rocks, the exciting thing is that we've seen a chemical signature that's never been seen before. That alone makes this an exciting discovery."
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∞ I am incapable of conceiving infinity, and yet I do not accept finity. - Simone de Beauvoir -
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hamandcheese
Sandwich


Registered: 06/02/08
Posts: 12,530
Loc: Next Level
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Re: a rock found being 250million years then the oldest rock known. [Re: snoot]
#8991943 - 09/27/08 12:01 AM (15 years, 7 months ago) |
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ROCKS ROCK!
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Legoulash
Stranger


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Re: a rock found being 250million years then the oldest rock known. [Re: hamandcheese]
#8992248 - 09/27/08 01:32 AM (15 years, 7 months ago) |
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Fucking nice hammer. Some quality shiz
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ToTheSummit
peregrinus



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Re: a rock found being 250million years then the oldest rock known. [Re: Legoulash]
#8992269 - 09/27/08 01:39 AM (15 years, 7 months ago) |
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Quote:
Rah said: Fucking nice hammer. Some quality shiz
Werd. Estwing FTW I own a couple Estwing hammers myself.
Oh, and back on topic...thats a bitchin rock.
-------------------- You invented the wheel....You push the motherfucker!!
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Madtowntripper
Sun-Beams out of Cucumbers



Registered: 03/06/03
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Re: a rock found being 250million years then the oldest rock known. [Re: ToTheSummit]
#8992922 - 09/27/08 10:09 AM (15 years, 7 months ago) |
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Banded Iron Formations are awesome awesome awesome.
My favorite rocks, I have a bunch on my bookshelf.
-------------------- After one comes, through contact with it's administrators, no longer to cherish greatly the law as a remedy in abuses, then the bottle becomes a sovereign means of direct action. If you cannot throw it at least you can always drink out of it. - Ernest Hemingway If it is life that you feel you are missing I can tell you where to find it. In the law courts, in business, in government. There is nothing occurring in the streets. Nothing but a dumbshow composed of the helpless and the impotent. -Cormac MacCarthy He who learns must suffer. And even in our sleep pain that cannot forget falls drop by drop upon the heart, and in our own despair, against our will, comes wisdom to us by the awful grace of God. - Aeschylus
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johnm214



Registered: 05/31/07
Posts: 17,582
Loc: Americas
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Re: a rock found being 250million years then the oldest rock known. [Re: Madtowntripper]
#8993072 - 09/27/08 10:56 AM (15 years, 7 months ago) |
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I was waiting for madtown to chime in.
And what's with the picture?
A picture of a rock with a professor's name in the caption?
Professor Rock?
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Madtowntripper
Sun-Beams out of Cucumbers



Registered: 03/06/03
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Re: a rock found being 250million years then the oldest rock known. [Re: johnm214]
#8993097 - 09/27/08 11:04 AM (15 years, 7 months ago) |
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Yeah, I almost posted a big paper that I wrote up on BIFs for a Geochronology class a few years ago, but I decided to spare everyone. I get too excited about rocks sometimes!
BIFs are so super awesome because these rocks were formed in extremely iron-rich ocean environments. The alternating bands are formed of oxygen-rich and oxygen-poor rock layers. Oxygen and Iron in solution form an iron precipitate that settles to the bottom to be covered by an oxygen-poor type of rock, usually chert, when conditions change again.
There are several theories to account for these oxygen-level fluctuations but one the most prevalent is this oxygen production is the signature of the earliest life on the planet, some kind of creature similar to a cyanobacterium. These creatures create oxygen as a waste product and as they bloomed and died during their life cycles from environmental changes they would have changed the oxygenation of the ocean and possibly caused conditions that would allow the banding to form that we currently see.
-------------------- After one comes, through contact with it's administrators, no longer to cherish greatly the law as a remedy in abuses, then the bottle becomes a sovereign means of direct action. If you cannot throw it at least you can always drink out of it. - Ernest Hemingway If it is life that you feel you are missing I can tell you where to find it. In the law courts, in business, in government. There is nothing occurring in the streets. Nothing but a dumbshow composed of the helpless and the impotent. -Cormac MacCarthy He who learns must suffer. And even in our sleep pain that cannot forget falls drop by drop upon the heart, and in our own despair, against our will, comes wisdom to us by the awful grace of God. - Aeschylus
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watchoutnow
mind'sonrecord/itsbeingviewed



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Re: a rock found being 250million years then the oldest rock known. [Re: snoot]
#8996665 - 09/28/08 01:50 AM (15 years, 7 months ago) |
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Cool. Thanks for sharing.
-------------------- I quit. Touch it. "My views ain't changed to live humane wait" -Eminem "Ya'll make me too rounded and I'm addicted, WTF I'm drunk. Wtf I'm high. Wtf I'm... Not sober... Sober block." -me crazily self. "From that what, knowledge of self - determination!" -Blackstar ----------------------------------------------------------------- Ever since I got braces shit gets stuck in my teeth. Make me *** bitch!
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Hematite
Newbee



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Re: a rock found being 250million years then the oldest rock known. [Re: Madtowntripper]
#8999876 - 09/28/08 08:31 PM (15 years, 7 months ago) |
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It will be interesting to see what kind of zircons are found in this rock, and if they will break the 4.404 billion year record.
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snoot
look alive ∞




Registered: 01/30/05
Posts: 9,644
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Re: a rock found being 250million years then the oldest rock known. [Re: johnm214]
#9002172 - 09/29/08 11:12 AM (15 years, 7 months ago) |
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Quote:
johnm214 said: I was waiting for madtown to chime in.
And what's with the picture?
A picture of a rock with a professor's name in the caption?
Professor Rock?
cut and pasted from bbc
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∞ I am incapable of conceiving infinity, and yet I do not accept finity. - Simone de Beauvoir -
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Madtowntripper
Sun-Beams out of Cucumbers



Registered: 03/06/03
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Re: a rock found being 250million years then the oldest rock known. [Re: snoot]
#9003571 - 09/29/08 04:21 PM (15 years, 7 months ago) |
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Hmmmm?
-------------------- After one comes, through contact with it's administrators, no longer to cherish greatly the law as a remedy in abuses, then the bottle becomes a sovereign means of direct action. If you cannot throw it at least you can always drink out of it. - Ernest Hemingway If it is life that you feel you are missing I can tell you where to find it. In the law courts, in business, in government. There is nothing occurring in the streets. Nothing but a dumbshow composed of the helpless and the impotent. -Cormac MacCarthy He who learns must suffer. And even in our sleep pain that cannot forget falls drop by drop upon the heart, and in our own despair, against our will, comes wisdom to us by the awful grace of God. - Aeschylus
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snoot
look alive ∞




Registered: 01/30/05
Posts: 9,644
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Last seen: 20 hours, 29 seconds
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Re: a rock found being 250million years then the oldest rock known. [Re: Madtowntripper]
#9005278 - 09/29/08 09:21 PM (15 years, 7 months ago) |
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/me drops the beat
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∞ I am incapable of conceiving infinity, and yet I do not accept finity. - Simone de Beauvoir -
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