Confirmed: Earth's Oldest Rock In Australia

SpamSlapper writes "Australia's ABC Science reports that ancient zircon crystals discovered in Western Australia have been positively dated to 4.374 billion years, confirming their place as the oldest rock ever found on Earth, according to a new study. The research reported in the journal Nature Geoscience, means Earth began forming a crust far sooner than previously thought, following the giant impact event which created the Earth-Moon system 4.5 billion years ago."

Comments

It comes from a land down under..

[jamesjw]

Where this rock is about as old as the social and development views of our current Prime Minister..

Re:It comes from a land down under..

[GloomE]

Why would he? He knows it can't be more than 10,000 years old. These "scientists" don't know what they're talking about.

Re:It comes from a land down under..

[mjwx]

Where this rock is about as old as the social and development views of our current Prime Minister..

However unlike Tony Abbott, the rock is worth something to Australia.

Ken Ham issues statement

[Brad1138]

"there's this book..."

Re:Ken Ham issues statement

[cascadingstylesheet]

"there's this book..."

You don't have to be a creationist to have doubts about this kind of dating.

It's pretty much the poster child of something that can't be confirmed by experiment.

Re:Ken Ham issues statement

[Mashdar]

I think gp's problem is with this specific type (U-Pb) of dating.
I don't understand how initial values are determined. (Is there some method by which the original ratio of the two elements is known? Or the proportion of radioactive isotopes?)

But, from the wikipedia article

Uranium-lead (U-Pb) dating is one of the oldest[1] and most refined of the radiometric dating schemes, with a routine age range of about 1 million years to over 4.5 billion years, and with routine precisions in the 0.1-1 percent range.[2]

so it does not sound at all un-tested.

While GP is correct that we cannot experimentally confirm the specific mechanisms here (radioactive Pb decay over one million+ years...) , we have a very good description of radioactive decay across the board (table?) and observational results sound extremely consistent. Direct experimentation is not the only form of scientific evidence, despite what [creationist intelligent_designist whatever_nut] might say.

Lots of Iron around there

[Harlequin80]

The area these are found are extremely high in Iron content. There are a number of high grade iron ore mines nearby. I wonder if there is any link between the high iron content and the formation of these rocks.

Re:Lots of Iron around there

[Anonymous Coward]

Not really. The 'Oldest Rock' they're talking about are actually individual mineral grains in a metamorphic rock that used to be sandstone. The zircon sand grains predate the rock they're in by about a billion years. The iron deposts you're talking about come from the same perioid of geologic time as the sandstone.

Re:Lots of Iron around there

[rve]

The iron formations are about 2 billion years younger.

The banded iron formations were formed by the earliest photosynthetic life, between 2.5 and 1 billion years ago. Oxygen produced by these single celled organisms formed iron oxide with dissolved iron ions in the oceans and precipitate on the ocean floor. This started when significant amounts of oxygen started dissolving in the water, and ended when most of the iron was used up. When that happened, the oxygen levels of the water suddenly increased, killing nearly all anaerobic life on earth, and opening the door for our aerobic ancestors.

Obviously

[El_Muerte_TDS]

The old stuff is always at the bottom of a pile.

Re:Obviously

[Rosco P. Coltrane]

Yes but, Australia being upside down, the bottom is at ground level.

Unfortunately

[Greyfox]

They had to kill the rock to confirm its age.

Did they finally date them?

[dutchwhizzman]

I'm sure AC/DC will be delighted with their new title of oldest rock on the planet.

Re:Amazing!

[dbraden]

I did not know that scientists had examined and dated every rock on (and every rock within) the Earth! The most spectacular part of this task was back when they dismantled Mt Everest, pebble by pebble, examining and dating every little rock, before re-constructing the mountain from all those sorted rocks.

I agree with your general sentiment regarding fake science, however, a little bit of reading comprehension will go a long way.

oldest rock ever found on Earth

It's not like the summary says "The oldest rock on earth!".

Re:Amazing!

[Calavar]

Fine, it's the oldest known rock, you pedant. It's still plenty interesting because the oldest known rocks up until know were only about 3.8 billion years old. There is the potential to learn a great deal about the early days of the earth from this rock. Oh, and obligatory xkcd: 1194

Re:wtf? Do you even understand the subject?

[rve]

And you don't have all the answers either

The 'rock' in question is a microscopic zircon crystal, not an actual chunk of rock. Think of it as a very hard grain of sand, that has been weathered off the rock in which it formed, deposited somewhere as sediment, which turned into sedimentary rock, and so on, perhaps a great many times, before it settled in the rock in which it was found.

The Himalayas started uplifting some 50 million years ago, but that doesn't mean the material in it can be no more than 50 million years old. The rocks weren't melted in the process. Who knows, perhaps there is a grain of zircon embedded in a chunk of sandstone in the Himalayas that's even older. Perhaps a geologist can explain why this is or isn't possible, but it would definitely be like searching for a needle in a haystack.

The reason for searching in places like Australia, is because exceedingly ancient rock formations are exposed there, significantly reducing the size of the haystack.