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Related: Editorials & Other Articles, Issue Forums, Alliance Forums, Region ForumsConfirmed: Oldest Fragment of Early Earth is 4.4 Billion Years Old
http://news.yahoo.com/confirmed-oldest-fragment-early-earth-4-4-billion-180642066.html;_ylt=AwrBJSCrSwtTTFUAB3zQtDMDBy By Becky Oskin, Staff Writer 19 hours ago
Confirmed: Oldest Fragment of Early Earth is 4.4 Billion Years Old
Ever heard this life advice? When solving a big problem seems impossible, break it into smaller steps.
Well, scientists just took one of geology's biggest controversies and shrunk it down to atomic size. By zapping single atoms of lead in a tiny zircon crystal from Australia, researchers have confirmed the crystal is the oldest rock fragment ever found on Earth 4.375 billion years old, plus or minus 6 million years.
"We've proved that the chemical record inside these zircons is trustworthy," said John Valley, lead study author and a geochemist at the University of Wisconsin, Madison. The findings were published today (Feb. 23) in the journal Nature Geoscience.
Confirmation of the zircon age holds enormous implications for models of early Earth. Trace elements in the oldest zircons from Australia's Jack Hills range suggest they came from water-rich, granite-like rocks such as granodiorite or tonalite, other studies have reported. That means Earth cooled quickly enough for surface water and continental-type rocks just 100 million years after the moon impact, the massive collision that formed the Earth-moon system. [How Was The Moon Formed?]
"The zircons show us the earliest Earth was more like the Earth we know today," Valley said. "It wasn't an inhospitable place."
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dembotoz
(16,832 posts)davidpdx
(22,000 posts)Separation
(1,975 posts)Everyone know that earth, man and his trusty dinosaur pet/ride is 6-7k years old.
1awake
(1,494 posts)Not how old it is or is not. This is pretty controversial. Really cool.
fleabiscuit
(4,542 posts)There's life in the hot springs of Yellowstone and the deep smoker vents in the pitch black deep oceans. They aren't inhospitable to the life living there now, and the Earth is pretty much like the Earth we know today. lol
blkmusclmachine
(16,149 posts)pangaia
(24,324 posts)Bernardo de La Paz
(49,036 posts)Enthusiast
(50,983 posts)But, because they are no longer where they were mined it wouldn't be of practical value. Unless we knew the source location.
pangaia
(24,324 posts)i wish they would last a little longer.....like a million years, or so.
LibertyLover
(4,788 posts)Thank you for posting this.
Lobo27
(753 posts)Joking aside, that is some awesome stuff. Science never seizes to amaze me!!
blackspade
(10,056 posts)I think Ham's head just exploded though.
CFLDem
(2,083 posts)3catwoman3
(24,043 posts)If I remember correctly, when asked what could/would get him to change his beliefs about things, his reply was, "Nothing." Gawd herself would have to seize him by the neck and tell him something to his face to shake his willingly ignorant complacency.
G_j
(40,370 posts)but for what, it's hard to say..
mountain grammy
(26,648 posts)but the important question is: does it violate our religious freedoms and can our children opt out of learning about it?
niyad
(113,552 posts)jeff47
(26,549 posts)Xithras
(16,191 posts)Attested to by the fact that our oxygen was generated by life forms that arose when there was no free oxygen at all!
jeff47
(26,549 posts)malaise
(269,157 posts)Oh My!!!
pipi_k
(21,020 posts)until they decide that God is just playing tricks on them to "test their faith".
That's what one of my Fundy sisters told me about dinosaur bones and fossils...
malaise
(269,157 posts)[URL=.html][IMG][/IMG][/URL]
Tree-Hugger
(3,370 posts)The devil just buried those rocks there to lead you away from God and into the fiery pit of Hell (aka Ted Nugent's underwear drawer).
Enthusiast
(50,983 posts)It's a fascinating process.
The geological history of the earth is a beautiful story. The more you learn about it the more satisfying it becomes.
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Nanjing to Seoul
(2,088 posts)Ahh. . .science. Help. . .they're trying to open my mind. Help! Jebus, help me! Smite the unbelievers. Carbon dating is a hoax!
pipi_k
(21,020 posts)Carbon dating isn't a hoax when it's used to date something like the Shroud of Turin.
Or maybe a boat that's purported to be The Ark.
Don't you see how that works?
Nanjing to Seoul
(2,088 posts)denverbill
(11,489 posts)If a radioactive particle decays at a particular rate, I understand you can measure the relative proportion of isotopes to get the age of the radioactive material, but that doesn't automatically get you the age of the rock, just the age of the radioactive particle. If I put a 100 year old coin in my jeans pocket it doesn't mean my jeans are 100 years old.
How do they know that when the rock was formed the radioactive components weren't already half decayed?
Not questioning the science, just trying to understand it.
petronius
(26,603 posts)of interest; they know the zircon fragments have moved around a lot. Rather, it's the age of the zircon crystals themselves that is of interest, because the overall composition of the zircon gives insight into the process and environment in which the crystal solidified. So by finding ancient zircon, they can tell something about geology and water content at the time of its formation, even though the zircon is now removed from the long-gone rock in which it originally lay. That's my take, anyway - I'm sure DU has a geologist (or 3) who will be along shortly...
denverbill
(11,489 posts)Zircon will form a crystal with Uranium, but not with lead. So when the zircon formed, all the molecules in the structure had to be uranium because the crystal wouldn't form with lead.
http://en.wikipedia.org/wiki/Radiometric_dating
Uranium-lead dating is often performed on the mineral zircon (ZrSiO4), though it can be used on other materials, such as baddeleyite.[20] Zircon and baddeleyite incorporate uranium atoms into their crystalline structure as substitutes for zirconium, but strongly reject lead. Zircon has a very high closure temperature, is resistant to mechanical weathering and is very chemically inert. Zircon also forms multiple crystal layers during metamorphic events, which each may record an isotopic age of the event. In situ micro-beam analysis can be achieved via laser ICP-MS or SIMS techniques.[21]
....
I was thinking it was more like uranium embedded in the rock, not chemically bonded.
nadinbrzezinski
(154,021 posts)seveneyes
(4,631 posts)I wonder if they use a pair of Zircon encrusted tweezers?