A recent Science Paper (as reported by Nature and Science Centric) has dated rock samples from the Nuvvuagittuq greenstone belt, on the eastern edge of Hudson Bay in Quebec, Canada, at a staggering 4.28 billion years old. The research team used the (somewhat unconventional for terrestrial dating) ¹⁴⁶Sm→¹⁴²Nd isotopic system, due to the lack of zircon being found within the rock. This means the date will have to be confirmed, preferably with zircons, for many to lend weight to the claims, but all the same, this is an amazing discovery.

It’s pretty staggering how old these rocks are. So let’s put it into perspective:

These rocks were formed 270 millions years after the Earth (4.55 Ga), which means they’ve remained reasonably unchanged for almost the entire history of the planet. They’ve survived 4.28 billions years of: plate tectonics including subduction and obduction, glacial erosion, meteorological erosion, chemical erosion, chemical alteration (maybe), or any other method of rock recycling. It also means we have pushed back the earliest date for continental material existing on Earth by 250 million years (the previous record was 4.03 Ga for the Acasta Gneiss, also from Canada).

These aren’t the oldest terrestrial material ever discovered, however. That title still belongs to zircons from the Jack Hills in Western Australia, that have been dated at a positively geriatric 4.4 GYr. But as a sample of rock, this is pretty exciting so far as early Earth chronology goes.

Geological timescale thanks to Chris Rowan at Highly Allochthonous.
Splash image to the left lifted from Nature, and courtesy of AAAS/Science.

2008-09-26 | by Chris | Comments (3)

Hi everyone.

Just a reminder that posts for the Accretionary Wedge #13 are due this Thursday (or Friday), your time (25th or 26th of September). Check out the original post for submission details and get those little space themed articles rolling on in!

You may also want to check out the upcoming and previous hosts of the Accretionary Wedge here.

2008-09-21 | by Chris | Comments (5)

Hello everyone,

It’s my turn again to host the geoblogosphere’s blog carnival, The Accretionary Wedge. This month for the Wedges thirteenth edition the theme, as chosen by me, is:

Geology in Space (pronounced Geologeeeeee in Spaaaaaaaace).

Geology doesn’t just happen here on Earth, it’s happening everywhere there’s a small amount of silicates being drawn together by gravity. This month, give yourself a few hours, pick a body within the solar system, and tell the world about the geology that goes on there. You could talk about yardangs on Mars, the extreme tectonics of Venus, the enormous equaitorial ridge on Saturn’s moon Iapetus, what the HED meteorites tell us about 4 Vesta, or anything else that may tickle your geological interest.

The Earth is so huge and varied geologically, just think about what else is going on, on the other 7 planets and thousands of other bodies in the solar system.

I’ll be handing my MSc thesis (which deals with the formation of the solar system) in on the 25th of September, so that’s the date for everyone to get their submissions to me on the weird and wonderful things that have happened since. Either email me (chris (-then the usual symbol-) goodshist.com), or post a link in the comment thread of this post.

Happy writing!

2008-09-10 | by Chris | Comments (20)

Well, I’m busy at the moment, not only am I racing against time to finish the first draft of the MSc thesis, I’m also frantically packing a bag. Tomorrow afternoon I’m leaving my little Pacific archipelago and heading for the bright lights and fast times of the UK and France.

The former issue above is the reason for there having not been a podclast in the last couple of weeks. Ron and I tried to record last week, but Skype refused to cooperate. This week I tried again, but everyone who normally joins was busy. That meant procrastinating (by writing bit of my thesis) and therefore, no podClast.

I’m going to try really hard to record something before I leave, but failing that, you’re going to have to wait another month before the next podClast is up. I’m sorry about that, but the situation causing this disruption is rather unique.

On the up side, I’ve thought ahead and I have at least one interview lined up in the UK (the first podclast interview, quite momentous), so the podclast isn’t dying, that’s for sure.

2008-07-15 | by Chris | Comments (5)

2008-06-26 | by Chris | Full Article | Comments (6)

2008-06-26 | by Chris | Full Article | Comments (4)

2008-06-25 | by Chris | Full Article | Comments (16)

American Dad encounters the Langley Falls Town Geologist. Without doubt the most accurate portrayal of a geologist yet seen on screen. And the breakfasts? I’d call them outstanding!

2008-06-20 | by Chris | Comments (4)

I decided the old goodSchist design needed a bit of a kick, so I’ve given it a little work over. Hopefully it works in internet explorer, but if not I’m going to be making modifications anyway, and I’ll do my best to fix any problems.

I’ve made the changes so I can make quick, short posts like you’re supposed to be able to do with blogs anyway. This way if I see something cool, or note-worthy, and I don’t want to spend an hour writing about it, I can just let my small readership know and move on.

I’ll still be writing my normal long articles and the podClat posts will be just as detailed as you’re used to. I’ve still got some things to work on , but the main functionality of being able to make short entires, like this one, was my primary objective.

2008-06-20 | by Chris | Comments (4)

2008-06-15 | by Chris | Full Article | Comments (1)