Oldest bit of crust firms up idea of a cool early Earth.

So I saw this article today that I thought I would share. It talks about how they have found the oldest piece of crust in australia in an outcrop. Its a zircon crystal that has been dated to 4.4 Billion years old !!! Now I know some say will say these dating methods are dodgy.... However if thats the case then most of the people believing that may not find this article interesting.

For the people that are interested in current dating methods and geology here is the article.
phys.org...

Now some of the things they were able to conclude are very interesting such as this little tidbit :

A 4.4 billion-year-old zircon crystal is providing new insight into how the early Earth cooled from a ball of magma and formed continents just 160 million years after the formation of our solar system, much earlier than previously believed.

Read more at: phys.org...

As well as this :

The study, according to Valley, strengthens the theory of a "cool early Earth," where temperatures were low enough for liquid water, oceans and a hydrosphere not long after the planet's crust congealed from a sea of molten rock. "The study reinforces our conclusion that Earth had a hydrosphere before 4.3 billion years ago," and possibly life not long after, says Valley.

Read more at: phys.org...

To me this is interesting. If our planet was possibly habitable just 160 million years after the formation of our solar system than to me it would seem that life could potentially be almost as old as the solar system its self. And its not that crazy of an idea to postulate that life could have been forming elsewhere in the solar system. Perhaps mars or other bodies that are now lifeless . But I Digress....BTW Here is a pic of the crystal they tested, the thing even looks ancient.

reply to post by CitizenJack


Since the earth is still forming today (thru meteoric accretion) I wonder how small a diameter it must have had back then? And how that could prevent the formation of life because the core might not yet be molten, thus no EMF, therefore no protection from the suns radiation and no atmosphere forming…?

reply to post by intrptr



Hmmmm.... Well I'll admit science and space is more of interest of mine than a career so the answer to those question I do not have.
Are you suggesting expanding earth theory ? Or something else ... a linky would be much appreciated .
I'll dig around the old interwebz to see what I can find related to what you speak of.


As far as no emf I'm not sure if one was present or not. However in the words of Dr. Ian Malcolm " Life will always find a way " . So perhaps were are just a bunch a pansies compared to the life forms present back then? Or perhaps there weren't any. My time machine will be done in 64 days so i'll be back with an answer very soon . J/k I do love to learn tho so if you got some knowledge for me dish it up . I find it best served cold.

Thanks for the dialogue.

CitizenJack


If our planet was possibly habitable just 160 million years after the formation of our solar system than to me it would seem that life could potentially be almost as old as the solar system its self. And its not that crazy of an idea to postulate that life could have been forming elsewhere in the solar system. Perhaps mars or other bodies that are now lifeless . But I Digress....BTW Here is a pic of the crystal they tested, the thing even looks ancient.

It's a big jump from what they said to that don't you think after all what was the atmosphere like , temperature and was there water???

reply to post by CitizenJack



This is an extremely important find to another of other thread's which suggest the possabillity of early life, It would be interesting if the crystal structure could provide any insight into how deep this was when it formed as that would also show the geological weathering of older rock above it. Great thread. S+F.

Man seeks and he finds, knocks and the door opens. The words cannot be more truth.

Our newest findings in science seem to be what people pondered on early in the field and were thought to be crazy (not gonna give any examples) yet many of our findings seem to be just those "cuckoo" ideas that people had.

This is an incredible find and should be read by all of our community.

This finding has me intrigued and the results have me even more so. I do not suspect the scientists would fake some results of this magnitude nor be influenced to do so. Though alot of guess work is done through existing paradigms and ideas, it may be close to the truth.

Nice find and thanks for posting this thread. We need more of those!

reply to post by CitizenJack


Ummm… the way I understand it…

life is possible on earth because of atmosphere which is possible because of earths electromagnetic field which prevents the suns radiation from sterilizing earths surface (like Mars).

The EMF surrounding earth is a result of the dynamo action of earths molten core which produces the field. This molten core is directly due to earths mass that is large enough to create the pressure to induce the molten core.

Millions of tons of meteor dust fall to earth every year(?). If we wind back that amount to 180 million years after the beginnings of the solar system that would imply the earth was a lot smaller and incapable of producing an EMF due to its reduced mass. Therefore no atmosphere, therefore suns radiation precluding life…

Or so I premised.

My question (I no math man) was how smaller was the earth at that period of its history? Were talking billions of years ago, right?

Sorry for the delay.

reply to post by intrptr


I think that's a fair assessment, unless we were wrong about a couple of things in our assumptions? If so, what assumptions would those be?

Sump3
reply to post by intrptr

 

I think that's a fair assessment, unless we were wrong about a couple of things in our assumptions? If so, what assumptions would those be?

The missing video…

Just kidding. A lot of conjecture there. None of us were around. What do you think might be big assumptions?

reply to post by intrptr


Lol : )

One wonders, if we were wrong how fast things form at the beginning.

By that I mean when the big bang took place, how fast did the galaxies form, and the solar system and thus the planets and suns? And their state at the beginning, I think those are the ones that we really need to look at, but we can't since it already took place.

And for me to go into my ideas about how the world works would be a whole new thread on it's own. Though I think that the big bang took place, but on a much more abstract and stranger than fiction level. As I think everything is the center of the universe though nothing is the really the center of it. Eye of the beholder idea of sorts, still not.

Also kind of hard for me to work out the correct set of words as I have to translate everything I say from Icelandic and the advanced English scientific terms aren't my strongest field.

Hope you get my picture though.

reply to post by intrptr


Ah I see where you're going with this. I would hope that the men and women in charge of figuring this stuff took those factors into account.

I could see however that maybe they are speaking in a purely geological sense. Biggest question here seems to be what are the requirements for an electromagnetic field to form. And the answer would be a molten metal core .Now what are the requirements for a molten metal core.... that would be the big question.

And on a side note I looked up The growth factor by meteoric waste there's actually a formula for it. When I'm not on my phone I'll see if I can post it. Now I know you said you werent mathematical and neither am i however I'm sure someone can come up with a rough estimate based on the equation. Ill get back to you when my internet comes back up.

reply to post by Sump3

As I think everything is the center of the universe though nothing is the really the center of it. Eye of the beholder idea of sorts, still not.

If you mean the Universe is infinitely big (no end) then I agree with you that "everywhere" is the center, and yet not.

Also kind of hard for me to work out the correct set of words as I have to translate everything I say from Icelandic and the advanced English scientific terms aren't my strongest field.

Didn't know that. Sorry for any loss in translation. My admiration for how hard that must be to translate. Always delighted to talk with people from far away.

reply to post by Sump3


Sorry, replying twice.

One wonders, if we were wrong how fast things form at the beginning.

Thats what I was thinking, the beginning of the solar system.

At some point as the Sun convulsed to be born (switched on) there must have been tremendous shock waves of material pouring out onto the ecliptic (the plane of the solar disk). This surely influenced the formation of planets in the young solar system. In my mind these shock waves may have been like striking a cymbal and the vibrations ringing the plane of the Ecliptic. Like vibrations that form matter into shapes, what do you call it in "resonant frequencies"?

The ringinggg of gravity and mass along the huge "cymbal" of the Solar system could form other singularities like planets quite quickly… or not. Once the Sun settled to a "steady state" of burning the planets were already there, maybe?

Just musing… I don't really know.

upload.wikimedia.org...

reply to post by CitizenJack

And on a side note I looked up The growth factor by meteoric waste there's actually a formula for it. When I'm not on my phone I'll see if I can post it. Now I know you said you werent mathematical and neither am i however I'm sure someone can come up with a rough estimate based on the equation. Ill get back to you when my internet comes back up.

Cool. I'll check back tmrw.

Hey all, as a geoscientist, I have worked on Zircon dating projects. This is an interesting development, but not an earth shaking revelation. Previously, the oldest dated Zircons were in the 4.3Ga age range (1) So this recent work has pushed back the "first proof' of crustal existence by a mere 1,120,000,000 years.
I know that is a lot of time, but geologists see things a little differently.

1.12Ga is a very long time, no doubt. But that being said, the maturity of the Earth in that timeframe is relatively unchanging. We are still talking about a very harsh and inhospitable place to live. Think "Hell". As for the talk about an earlier, cooler, hydrosphere bearing surface...
How to put this ~ "Great claims require great proof." A zircon date (thru radio-isotope dating of uranium atoms trapped in the Zircon crystal lattice) represents a "made on" date. Zircons have one of the highest melt points of any mineral. Combine that with their extreme resistance to erosion and you indeed have many tiny "made on" stamps throughout any given rock.
As a magma cools, the atomic ingredients begin to bond together; different minerals form out a different temps. Zircon is one of the first, and in reverse, to destroy (or reset the clock) on that Zircon requires near-melt temps.

What the crystals don't come close to telling us is whether or not a global crust was sustained in perpetuity. What I mean is that there was likely very rapid and violent geologic changes happening to that early crust. Constant meteoral bombardment combined with these changes could easily see large sections of that young crust destroyed and melted down. The zircons speaks to that particular region's age, but not to the Earth as a whole. For real evidence of the cool earth theory, zircons from all over the globe would need to be dated to the 4.4 results.

All the same, it's a great step forward in Zircon dating, and it may very well turn out that in the future the cool earth theory plays out...or it might end up that the dating of galactic formation may be a little young.

reply to post by blamethegreys


Just to throw a spanner out there, as an expert on this could this actually be non terrestrial Zircon, possible from the impact which may have formed the moon.

reply to post by LABTECH767


Great spanner tossing, that's an interesting point. [had to erase and restart the reply after a bit of research]

Jack Hills Fm: Sedimentary siliciclastic rocks, interpreted as alluvial fan-delta deposits, are the major lithology. Minor mafic/ultramafic rocks and banded iron formation (BIF) are also found in the sequence. The overall sequence is generally considered to be a granulite gneiss, which has undergone multiple deformations and multiple metamorphic episodes. The protolith age of the Narryer Gneiss Terrane is variable, but generally considered to be in excess of 3.6 Ga (billion years).

Thanks Wikipedia!

In a nutshell, it is a reworked sedimentary deposit from ~3.6Ga+. Soooo in theory, your thought could be correct; that the zircons' provenance might be non-terrestrial.

Reconstructing Earth history from these ancient times is more voodoo than science, IMO. For each ounce of evidence, there is at least twice as much arm waving.

But that being said, I can't imagine these findings getting published based on one sample from one location. I have to believe that there are a respectable amount of 4.4Ga zircons from multiple areas. But as you point out, the moon-forming impact wasn't a small matter at all...

reply to post by intrptr


My thoughts exactly. The world is of course in basics a "symphony" in combination with lots of other factors of course.

But yes, this seems to be a reasonable assumption.
Guess we won't really know the answer until our scientists have greater proof and more conclusions.

Always fun and interesting though to ponder new ideas though I am no doubt just a layman.

reply to post by intrptr


As promised here you go.

IN ordinary circumstances, about three meteors are visible per hour at a given place. Such average meteors are visible at a distance of at least 100 km., and their mass seems to be in the neighbourhood of 6 × 10-3 gm.1. Thus the mass falling per hour on an area of order 3 × 1014 cm.2is about 2 × 10-2 gm. ; or 6 × 10-17 gm. per square centimetre. Taking the density as 3, we find that the rate of accumulation is 2 × 10-17 cm. thickness per hour or 2 × 10-5 cm. in 100 million years.

This is from a Harvard extension that I pulled up on google. Hope this helps lol .Dont forget to take into account the heavy bombardment period during the early years of formation so grab a pen and paper and dont forget to carry the one .