[meteorite-list] puzzling Putorana

From: Paul Dudley <pdudley_at_meteoritecentral.com>
Date: Thu Apr 22 09:54:10 2004
Message-ID: <002701c1bcba$8fa0bee0$078469d1_at_eznet.net>

This theory makes sense to me. I'll have to go read Norton's article that
is sitting on my heap of things to read someday, but I the idea of elemental
iron from the core making it to the Earth's surface seems a bit far-fetched.
Reduction of magmatic iron seems more plausible--but then I'm primarily a
soft-rock geologist. Any geochemists have any thoughts on this?
--Paul


----- Original Message -----
From: "Dave Harris" <entropydave_at_ic24.net>
To: "metlist" <meteorite-list_at_meteoritecentral.com>
Sent: Saturday, February 23, 2002 4:17 AM
Subject: [meteorite-list] puzzling Putorana


> Hi there,
> I have just read Mr. Norton's article in this quarter's Meteorite magazine
> on Putorana where he speculated that the iron in the basalt was derived
from
> mantle plumes conducting iron from the core to the magma chambers in the
> lithosphere - I was just wondering how actually plausible that mechanism
> actually was.
> I thought that a more likely scenario for the creation of Putorana iron
may
> have been the effect of a magmatic plume coming into contact with a highly
> carbonaceous sedimentary deposit and the iron compounds are then reduced
to
> native iron (much in the same way that commercial iron is produced by
> reacting with coke). I accept that the sedimentary deposits would have to
> be subducted to quite some depths before the appropriate temperature and
> pressures arose, but it still seems more likely a scenario to me than a
> outer liquid core streamer of iron travelling a couple of thousand
> kilometres upwards, against gravity and still keeping the iron in a liquid
> enough state to mix with magma.
>
> Any ideas? I wonder if there is any overriding chemical evidence that the
> iron is sourced from the core rather than liberated as part of a reduction
> of mantle silicates and oxides (possibly the presence of Ni in the iron is
> the evidence that supports the core theory - I dunno!)
>
> Don't laugh at me if I have written a load of rubbish here! I need to
learn
> and only by thinking about this stuff and making gaffs will I learn
> anything - some of you people out there know more about Geology than I
will
> EVER learn, so I bow to your undeniably profound knowledge!!!
>
> Ideas/opinions please!
>
> --
> In gentle decay,
> dave
>
> IMCA #0092
>
> imca_0092_at_hotmail.com (for IMCA member contact)
>
> http://www.meteorites.ic24.net/index.html
>
> http://www.meteoritecollectors.org
>
> "I have a proof that x^n+y^n=z^n never has integer solutions for n>2.
> However, it won't fit into my signature file...."
>
>
>
>
>
>
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Received on Sat 23 Feb 2002 05:36:38 PM PST