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Jntg4

Geologic Data Scale

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Wrangellian

I was wondering the same thing... that's a pretty specific figure!

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Auspex

I was wondering the same thing... that's a pretty specific figure!

Horseshoes and hand grenades...

The press is going to publish "The Figure", while the experts in the field know and accept some specific statistical wiggle room.

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Ludwigia

Very interesting! :popcorn:

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Wrangellian

So it's a few days older than they previously thought... woo hoo

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Jntg4

New news says the moon is younger than previously though, between 4.4 and 4.45 billion years old. Updated timescale for 4450 MYA.

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Wrangellian

Is this new date widely accepted or widely disputed? If it's confident I'll update my Precambrian scale also.

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Missourian

"Luna, you don't look a day over 3.9 billion."

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Wrangellian

So if this is true, and the date for the Jack Hills zircons remains as is, then the two dates are pretty close and we're looking at some of the first crystals to form out of that molten rock after the earth was hit!

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Wrangellian

Hmmm.. I thought I had posted an earlier version of this here but I guess we were just emailing them back and forth...

Anyway, thought I'd put this here just for the sake of interest/discussion: my proposal for alterations to the alternate Precambrian timescale proposed in 2012.

post-4372-0-41800000-1396261220_thumb.jpg

Some points:

I didn't like the long undivided 'Rodinian' so I reincorporated some of the current divisions.

Also I took the liberty of subdividing the Cryogenian, as I think the different glacial events during that time are becoming clear (hopefully true of the Ediacaran as well - see my other timescale under 'Documents').

Some of the new divisions closely matched the old ones as well so I included the older names as alternates. Another alternate is the Huronian for the 'Oxygenian' - why not use a name that has long been in use for that glacial period and therefore perhaps more familiar?

Likewise, it looks like the new Methanian and Siderian are based on the Fortescue and Hamersley Groups in Australia, and to use specific locations to name geochron. units is not new (see also Pongolan, named for the Pongolan supergroup).

Also I revamped the Hadean - date of moon formation approx, I guess that date is still 'up in the air' - and so is the age for the Nuvvuagittuq rocks I think (haven't looked into that lately).

Some of the divisions/names I have proposed will depend on the acceptance of others; for instance, I would suggest that if the Nuvvuagittuqan is accepted, the preceding period chould be the 'Jackhillsian' (if there aren't any older zircons found elsewhere). Otherwise both together could be the 'Zirconiferous'.

Edited by Wrangellian

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Wrangellian

I understand they have moved the base of the Cryogenian up to 720Ma, extending the Tonian and therefore making Gradstein et al's 'Rodinian' even longer... which makes me wonder whether the interval in question ever had anything substantial to base the 850Ma boundary on. If so, maybe that will become a new period someday. Anyway, the change has led me to tinker with it some more...

Does anyone reading this know whether there is a new version of Gradstein yet and whether the proposed Precambrian revision is still included, and whether it has changed any?

post-4372-0-43683100-1458474409_thumb.jpg

The original scheme from Geo. Time Scale 2012:

post-4372-0-68453300-1458474404_thumb.jpg

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DPS Ammonite

Wrangellian,

Wow, good job! I did not realize that the Precambrian could have so many divisions. First year geology students will soon have a lot more to memorize.

How do you go about presenting your proposed changes? Do you have to publish something? Has anyone with the group that creates geological timescales discussed any of your suggestions with you?

Regards,

John

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Wrangellian

Thanks John, I have no idea how to present it other than posting it here. I guess you would have to publish it if you could. Since I am no professional they would ignore me anyway, so it's just a pastime.

It is mainly just a synthesis of their proposal and the current version with the Ectasian, Calymmian, Stenian, etc. Who knows what revisions the officials will end up deciding, it might be piecemeal or they might just accept these people's system all in one go... I still don't know whether there has been anything new on this since 2012 other than the change of the base of the Tonian (from Wikipedia).

In the meantime I've been improving it more, here is the updated version:

post-4372-0-24646200-1458994085_thumb.jpg

Edited by Wrangellian

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TNCollector

This is really cool! Would you mind if I put a link to it on my website http://www.paleoarchiver.com ?

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