Geologists have just discovered the oldest terrestrial rock yet: some badly battered bit of something called a faux-amphibolite from Northern Quebec, Canada that has been dated to 4.28 billion years ago. I'm afraid most of the paper is way above my head — lots of radioisotope measurements, discussions of the details of the local geology, etc. — but I can at least note that this means Ken Ham is wrong by a factor of over 713,000. I am impressed by both the age of the rocks and the magnitude of the error a creationist can sustain without exploding into a cloud of pink pixie dust that fades to the sound of waning calliope music.
O'Neil J, Carlson RW, Francis D, Stevenson RK (2008) Neodymium-142 Evidence for Hadean Mafic Crust. Science 321(5897):1828-1831.
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...Yay! We have old rocks!
Pretty damn awesome that we finally have use for a dating technique that could only previously be used on meteorites. Yay for the Earth's ability to preserve itself!
Someone here linked to an Australian story the other day: apparently a fossilised reef near Adelaide (I think it was) show evidence that pushes mulitcellularity 80 million years further back into the pre-Cambrian.
I'd love to hear more about that.
Boo, the article isn't yet available on Web of Science.
The earth sciences field needs its own version of arXiv.org ASAP!
I heard a rumor there was a partial sneaker print!
How old, exactly, are these rocks dated to be?
Who will be the first to make a Mick Jagger joke?
the ham lake forest fire in the BWCA a cleared off vegetation on one of the lakeshores and revealed the underlying bedrock. a geologist hiking noticed a 2 billion year old extraterrestrial visitor lying on the ground. no, not an alien, a chunk of a meteor:
http://minnesota.publicradio.org/display/web/2007/05/24/meteor/
kinda cool. minnesota has 2 billion year old stuff lying around. i think voyageur national park has exposed primordial rock too, that is 3 billion or so years old also. saw that on a PBS special.
The rocks data between 3.8 and 4.28 billion years. For a more detailed summary look here.
700000 isn't too bad compared to magnitutes of error in cosmology, which in one rather embarrasing case reaches as high as a factor of 10^100 for estimates of energy density of space.
Why can't religious fundamentalists understand that the great antiquity of the Earth is apodeictic? (Rhetorical question.)
So does the republican presidential campaign...
Thanks, I'm here all week. Try the Veal Cheek Ravioli.
From New Scientist
Teach the controversy!
The Flying Spaghetti Monster put them there to test our faith. Their resemblance to meatballs proves intelligent design.
4.4 to 4.5 Ga
Rock of Ages--Kenneth Ham
Will deny that's what I am
So much older than the flood
So the myth, is just a dud
Rock of Ages--Kenneth Ham
Will deny that's what I am
Any response from the Bible websites yet?
It amazes me how much creationists quote from Answers in Genesis as if an educated person would be impressed by brain-dead liars.
Wait a minute! How the hell can those rocks be 4.28 billion years old when the earth is only 6000 years old! What are you trying to hand us? This is like saying that some galaxies are older than the Universe. We are freaking creationists and don't buy into that science crap. Next thing you'll be telling us is that Gannymede is a moon and not a planet! Do you think we are all morons?
> It amazes me how much creationists quote from Answers in Genesis...
Where else could they go? ;-)
The concept of that amount of time hurts my head. Can we talk about kittens now?
I love isotopic dating! Yay for really old rocks!
Then again, someone like Behe accepts that the world is four and a half billion years old, which means that God was able to design life in a mere three to four billion years--still getting a lot of it wrong.
Ham is at least capable of consistency (albeit a consistent application of stupidity and prejudice), while the old-earth IDiots are not.
Glen D
http://tinyurl.com/2kxyc7
I've always wondered... if the oldest rocks we can find are 4+ billion years old... what if the "original" rock on the planet has been cycled back to the core and melted, lost forever?
Wouldn't that mean, (a) that the Earth is at least somewhat older than we could ever determine, and (b) the precise age of the Earth isn't quite determinable from dating the oldest rocks alone?
... just a little confused about this.
Huh. That's amazingly appropriate.
Sorry to inflict everyone with my own earworm
It's a fairly safe bet that most of the inner solar system developed at the same time. So we can date the Earth, Mars, Venus, asteroids floating round... what ever we can we get our hands on. When we look at this "bigger picture" we come up with an age of approximately 4.5 billions years for the bodies in the inner solar system.
"How the hell can those rocks be 4.28 billion years old when the earth is only 6000 years old!" - Holbach
Obviously because one biblical year equals approx. 700 thousand rock years. If you can't handle that, well, I'm sorry.
"Wouldn't that mean, (a) that the Earth is at least somewhat older than we could ever determine, and (b) the precise age of the Earth isn't quite determinable from dating the oldest rocks alone?"
The answer to both is yes. When the earth formed the surface was molten. So there were not crustal rocks. Even after the crust began to solidify, asteroid impacts kept remelting and smashing up the crust.
Geologists date the formation of the earth by indirect methods. The oldest meteorites date around 4.6 billion years, so this must be when the solar system was first forming.
I haven't looked at the paper yet, but I'm still trying to figure out what a 'faux-amphibolite' is. A rock full of fake hornblende? Phony pargasite?
Once the creos get hold of this they will play up the faux and age aspects. That's about as certain as tomorrow's sunrise.
Sigh.
calladus posted:
Sorry to inflict everyone with my own earworm
I'll see your "Blinded By The Light" and raise you a "Mighty Quinn."
Or were you perhaps referencing the original Springsteen version (not that Manfred Mann wrote "Quinn," either)?
Old rocks, indeed.
No kings,
Robert
That's an interesting mental image.
Spinoza - I've wondered about this myself. According to TO, this is indeed the case. TO is often riddled with articles written about geology, often with mind-splattering terminology - but this at least was conveyable to non-geologists: the measured age of the oldest rocks is merely a lower limit to the the amount of time since the formation of those rocks. I wonder if any geologist has ever taken a different approach to dating the ancient earth, for example, by saying that "the earth couldn't have been older than somesuch" because of this or that. I can imagine that the earth can't be 14 billion years old because I doubt that stuff like Uranium could ever have been formed in a "first-generation planet", but really, how old can the earth get if it's not "just 4.5 billion years old"?
(.)(.)
Spinoza, in short, yes. The oldest meteorite dates we have are somewhere around 4.6Ga, which we take (for a bunch of reasons) to be close to the formation age of the solar system. It has long been figured that the earliest rocks (what people love to call primordial), the first stuff that would have crystalized out of the melt to form the "infant" crust, would mostly, if not completely, have been recycled early on by the tectonic engine. So then, the earth would always be older than we can directly measure. If the currently accepted mechanism for generating the initial continental crust is accurate (which I won't bore people with unless someone asks for it), then there are some problems with that model which argue, in theory, that somewhere out there there could be real "primordial" igneous rock. Indeed, I think that the 4.28Ga age on these ultramafics, if accurate, tends to argue in that direction (and given the last sentence of the abstract, the authors think this too).
But regardless, the answers to both of the questions in your second paragraph are probably yes, as far as we currently know.
O'Neil: Hey crystal... care to come on over and polish my basalt column?
(WHACK! chondrite to the head)
To throw a further wrench into the works, don't mafic and ultra-mafic rocks weather relatively quickly at surface Earth temperatures and pressures, further reducing the likelihood that we'll ever find 'the oldest' rock?
@Brownian, yes, some of the minerals that are "dominant" within mafic and ultramafic rocks tend to be rather cranky and unstable at surface temps and pressures. So yeah, they tend to weather more quickly than other common rock forming minerals (e.g., quartz).
Getting 6,000 when the correct answer is 4.28 billion is an error of 0.09 Dembskis.
Getting 4.28 billion when the correct answer is 3.8 billion is an error of only 0.00079 Dmb, about 114 times more accurate.
NY Times article w/pictures.
http://www.nytimes.com/2008/09/26/science/26rock.html?ex=1380081600&en=…
I wonder how many emails Dr. Myers got with this info. I saw the article in La Presse (local paper), hunted down the Science Mag online blurb and shot him a short email. I must admit that Dr. Plait got an almost identical email.
But, he hasn't picked up on it yet. Mark 1 point for the Squids...
Woot @ 32
"Hey, screw off; that old rock is ours!"
you are not looking through a biblical glass PZ!
In 1994 I played the Scopes character in "Inherit The Wind". The actor playing Darrow, (a great guy named Warren Hammack), at one point would lean over to consult with an expert witness sitting behind me. He'd show the guy a rock he'd had on the table in front of us and whisper, "How old would you say this rock is?" One performance the other actor looked him in the eye and whispered back, "It's my scientific opinion that this rock is 6,000 years old." At which point Warren, without pausing a beat, raised his eyebrows and said, "That old?"
Finally! After 150 years, we finally have a piece of evidence we were looking for, something showing that the Earth is older than 6000 years! I expect Creationism to fall sometime later today, as defeated fundamentalists intellectually retreat to a nuanced, Spinoza-like theology.
Seriously, the finding is pretty cool, but its not like Ham wasn't already off by 6 orders of magnitude before this discovery.
Putting on my geochemist hat: beyond the oldest-rocks angle, this is some pretty cool stuff!
The idea behind their use of the isotope 142Nd is that 142Nd only forms, so far as we know or can tell, from the radioactive isotope 146Sm. 146Sm has a short enough half-life that any of it which was in existence in the early solar system would have become extinct early on in Earth history.
When the mantle melts partially to produce igneous rocks, chemical differences in Sm and Nd tend to send more Nd into the magma (soon to become the crust) and concentrates Sm in the mantle. Thus any heterogeneities we find in the proportion of 142Nd in Nd in the Earth must be due to **early** melting events, before 146Sm was extinct.
Early (3.6-4.0 billion yr) rocks in Greenland show relatively high 142Nd (higher than the "terrestrial standard"), showing derivation from a higher-Sm mantle. This new finding of rocks with lower 142Nd than the terrestrial standard is from a (perhaps complementary) lower-Sm mantle source.
Maybe looking at both of these bodies of rock we can get a better handle on mantle convection (which tends to erase heterogeneities over a long enough time) and related processes in the earliest period of Earth history. Really cool!
/geochemist hat
Hmm, so does that upper age mean that according to the Giant Impact Theory, this rock would actually be older than the collision with Theia? Very little would have survived that, I imagine.
Cuttlefish @16:
Aaaaaaaaaaaamennnnn.
Nentuaby @ 45: to my knowledge most estimates for the collision with Theia are 4.5 billion years or earlier, with the youngest estimates at a little over 4.4 billion. Plenty of time for the Earth to settle down.
PZ wrote: "some badly battered bit of something called a faux-amphibolite from Northern Quebec"
(I put on a creationist tinfoil hat)
"Hey, it's faux-amphibolite! It's not a real rock! This is just a fraud by the neo-Darwin cabal!"
(I rip off tinfoil hat, clutching at my temples)
"Oww, that hurts! How do they do that 24/7?"
Rock of ages - Kenneth Ham
as full of shit
as a can of Spam.
*ducks*
Just curious: is anyone looking for Theia, or is looking for an earth-sized rock travelling at a decent clip away from us for the last 4.5 Ga a ridiculous prospect for currently available technology?
I retract my earlier question - I thought Theia was a comet/asteroid/what-have-you and not a part of the solar system's formation.
Ham is off by six orders of magnitude!
The error value of reality is still four orders of magnitude better than he is.
Not that anyone in that camp even knows what an order of magnitude is...
I like ham! Car-bon dating. Hundred thousand years! Wait ... I like ham!
OK, it is pretty cool. Woot! for old rocks, but has everyone here already checked out the so-called "Dark flow" recently noted?
http://www.space.com/scienceastronomy/080923-dark-flows.html
I love how weird our universe is!
Dahan@54,
Amazing. Must by Cthulhu! Those lucky galactic clusters are going to be eaten first!
Dahan @ 54
Thanks for the link and info. I knew of this latest astronomical phenomena, and just latest to make my brain swim with the workings of the great Universe. Damn, we'll all be dead by the time we get to walking around on Mars which I believe we should have been doing by now if we were not diverted by all the conflict and religious crap on earth. Astronomy is a discipline that frustrates one because of the time and distance needed to delve into the wonders of the Universe. Fascinates the hell out of me!
CANADA ROCKS!!!
(Im sorry, I had to)
Is that something to add to an order of calamari? :-)
"Any response from the Bible websites yet?"
I'm sure they'll think of something. They wouldn't have much to do if it weren't for all these new scientific discoveries to deny.
Dahan @54:
Duh! It's Gawd.*
*This message brought to you by IDiots for Science.
Wait year, it should get even weirder. Ain't science fun!
There could be a wee small problem. For what it is worth, some people think the decay constants may not be constants. Check out Jenkins et al. (2008) 'Evidence for correlations between nuclear decay rates and earth-sun distance', arXiv:0808.3283v1 [astro-ph] 25 Aug 2008. This could through a bit of a monkey wrench in things. Someone better get ahold of Jenkins et al. and tune them up.
Spinoza #23
Yes. Meteorites help. See for example
http://www.talkorigins.org/faqs/faq-age-of-earth.html
What's amazing is that with all the remixing/reheating of terra-not-so-firma through the ages, we can still find (non-meteorite) rock on the surface that goes way, way back.
First glance: the hills are about the same as they were in grandpa's day and most likely they've been that way since the earth was created.
Second glance: Over long ages, the crust of the earth has been reworked many times; almost everywhere you look, the rock you see is much younger than the planet, and often very different from what you expect to see in unreworked rock.
Third glance: If you explore earth in enough detail, you find small exposures or rocks or bits of rocks which have survived, relatively unchanged, almost all of the reworking but the very earliest, hence are nearly as old as the planet.
Then why in the name of GUT do we see the same decay rates of radioäctive elements in supernovae no matter where in the universe they happen?
It's not just the earth the creationists say is 6,000 years old. According to Answers in Stupidity and other Bible websites the entire universe was magically created 6,000 years ago. It's extremely difficult to believe anyone could be that insane, but millions of Americans think the zillions of stars of the universe were poofed into existence 2,000 years after people started breeding cows.
Somebody did the math. A 6,000 year old universe is as wrong as the idea that New York City is 24 feet from San Francisco.
Why don't you tell us why everything in the solar system points to roughly the same beginning age, if that is plausible? Why is the sun about four and a half billion years old according to stellar evolutionary models, and so are primordial asteroids according to an entirely different metric?
As important, what difference would it make to the subject at hand if the claims were true? We're talking about earth rocks in this thread, and earth almost certainly hasn't changed its distance from the sun very much since those rocks formed (or believed to have formed).
Astronomical dating correlates closely with radiometric dating back a hundred million years, at least.
Glen D
http://tinyurl.com/2kxyc7
And I was happy just to hold a 3+Ga komatiite and see it in thin-section...
Yeah, it's over my head, too. I'm envious of people who can tell that one rock is older than another, but I just can't grasp how they do it.
Yeah, the 'constants aren't quite constant' idea is more along the lines of constants change very slowly over billions of years (almost unnoticably so); not a 4.2 billion year old rock could actually be 6000 years old, and scientists [ie/ the leading experts on their respective fields of study] just never thought of it.
And 6000 years, are you kidding me! What, the Sumerians started building pyramids shortly after everything came into existence?! How can people be that dumb! (I know the answer: Religion)
Well, duh. Of course there is some relationship between decay rates and the earth-sun distance. The Sun is the major gravity well around these here parts. The Earth moves a little up and down that well. GR tells us that being in a gravity well affects the flow of time. We have to know that relationship pretty damned accurately in order to have GPS.
I don't think it will add up to quite what the religiots would like it to.... and no, I'm not going to even try to do the math right now. Let some Astrophysicist reader do it.
Michelle:
Indeed. That, snow, poutine and maple syrup. And abandoned churches where the average parishioner is about 80 years old. I say, what more can you ask for ?
It is indeed. Surety of reality is for the weak!
Kemist@71,
Don't forget the musk oxen!
Nick Gotts:
Well, that's more of a Nunavut/Greenland thing than a Quebec thing. We have moose, though (mmmm... moose steak. It's almost season now.). And humongous hydroelectric dams.
Sili@3,
Me too.
The current sun(population 1) and its satellites (earth,mars etc.) should have formed at the same time.Wiki gives 4.59 billion (tho I have seen data that eludes to a longer period).The earth would have been smaller and waterless for many years until it collected(by collected I mean large bodies and subatomic particles from both the solar system and interstellar sources) enough mass to distinguish between a recycling process and plate tectonics. The collection of material would have began from the stellar clouds and definite orbits established after the sun (fired up) At some point of mass collection,the recycling phenomena would have given precedence to the tectonic process and data retained on top(the rock)would not be reclaimed.The lithosphere thus preserving information when the recycling process moved mainly to the lower spheres when enough mass had been collected. The process is controlled by the distance from the sun,amount of power provided by the sun,and the mass of the sun.
The expansion of the earth by collection still continues today as we can see by meteorites,sub-atomic precipitation, and dust collection experiments such as preformed by Dr.brownlee(NASA)ect. The earth acquired enough matter to the addition of 22 inches in 2007.The recycling of the earths matter still continues to this day as seen by the ocean rifts and volcanism.The movement of plates can still be seen (well ask the folks in California).
The question is at what point did the earth collect enough matter to lower the convection process to the lower spheres and at what point do we call it suitable to begin the evolutionary process?
I would say it was a long long time ago.
Reminds me of grammar school "theology":
Could god make a rock so old that it predates him?
#3 Sili
#75 Nick Gotts
I posted a link to the story on the "A conversation about everything in the universe" (post #11) thread after listening to one of those responsible for the find on the radio programme "Bush Telegraph". You can still download that MP3 here..good story.
22/09/2008 | Download Audio - 22/09/2008
Ancient reef discovery in Australia
http://www.abc.net.au/rn/bushtelegraph/
The initial link I posted on the other thread was for the story "Ancient reef discovered in outback" on a Science Alert (Australia & New Zealand) page.
Exciting stuff :)
Conservopedia?
Oh and don't forget that according to AiG's top geologist, this planet is both 4.28 billion AND 6000yrs old!
Will the Real Dr Snelling Please Stand Up?
http://www.noanswersingenesis.org.au/realsnelling.htm
Yes, but with the clock bobbing in and out of the gravity well along with the sample the observed decay rate should be unaffected by time dilation. I do wonder how well environmental effects were corrected for with the detectors; there are after all plenty of factors in the environment with seasonal variations. New physics would be exciting unfortunate though the FUD possibilities would be.
@66 Glen Davidson
After reading your link(very intriguing by the way)one could hypothesis the discussed phenomena on a grander scale,say on a universal scale? just asking.
Sauceress@78,
Thanks!
Thank you, Sauceress.
The first bit about drought and damming was fascinating.
And the interviewer is really good - down-to-earth but clever questions. And still fun! "Plants? Animals? What have you been doing for the past four years?!"
I think the links I saw was just to press releases or summat, but also on ABC.
Hope PeeZed writes a bit once he has time. I'd love to see some pictures too.
Someone told me the rock was scrawled with instription "J McC was here"
Calladus, I had that earworm for several years. In the Mac laptop I got in 1991, the sound of the hard disk starting up sounded just like that rising electronic whine in the Manfred Mann version, so every time I opened the thing up the next thing in my head was "The calliope crashed to the ground! And we were blinded by the light..." Sometimes quite distracting.
Longtime Lurker, #77
Can God make a rock so discerning it refuses to date Him?
Any ... way,
This oldest (so far) rock, are we talking igneous or metamorphic?
NJ@28:
faux-amphibolite is described in the paper as being composed of mostly the amphibole cummingtonite (great mineral name... i think) instead of the usual horneblende.