[meteorite-list] puzzling Putorana

From: Fred Olsen <debfred_at_meteoritecentral.com>
Date: Thu Apr 22 09:54:11 2004
Message-ID: <005e01c1bf24$73032b80$2a04560c_at_fred>

Hello, All

I was just looking at my sample of iron from Disco Island. It weighs about
350 gr. and is about the size of a handball. I ground a corner off to have
a better look at its structure and found it looks more like a silicated iron
meteorite with a continuous field of iron surrounding small blebs of gray
silicates. I would guess 90% iron and 10% silicates.

 My slice of Putorana is about 50/50 iron /silicates. I do recall seeing a
sample of iron in basalt from Germany that looked a lot like Putorana.
Regards, Fred Olsen
----- Original Message -----
From: Treiman, Allan <Treiman_at_lpi.usra.edu>
To: metlist <meteorite-list_at_meteoritecentral.com>
Sent: Monday, February 25, 2002 1:06 PM
Subject: RE: [meteorite-list] puzzling Putorana


> Hi, all -
>
> With Matt Morgan's help, we've just finished a paper
> on the Putorana rock, and it should be published in
> July (?) with the Meteoritical Society meeting abstracts.
> The paper is bigger and more formal than the article(s)
> in Meteorite . If you'd like a preprint, send me your email
> or postal address!
>
> Personally, I'm not real keen on the Putorana iron coming
> from the Earth's core. It seems like an awfully long way for
> heavy stuff like iron metal to rise (or be carried up).
> The Diskoisland metal supposedly formed when molten basalt
> hit coal seams. The reaction was like smelting - iron oxide in the
> basalt magma reacted with the coal, and produced iron metal. That
> doesn't seem to work for the Putorana stuff, as the basalt is too rich
> in iron -- if iron had been smelted out of it, the basalt would be poor
> in iron.
> My current guess is that the iron metal came from iron sulfide
> liquid. There's a lot of iron sulfide ore in the Putorana/Noril'sk area,
> so having sulfide is not a problem. Perhaps the sulfide could get
> "roasted" naturally, and drive the sulfur off into the air. The iron would
> be left behind as metal. Just an idea. Perhaps our Russian friends
> know more about Putorana??
>
> Cheers!
> Allan
>
> Allan H. Treiman
> Lunar and Planetary Institute
> 3600 Bay Area Boulevard
> Houston TX 77058-1113
> 281-486-2117
> 281-486-2162 FAX
> treiman_at_lpi.usra.edu
>
>
> -----Original Message-----
> From: Dave Harris [mailto:entropydave_at_ic24.net]
> Sent: Saturday, February 23, 2002 3:17 AM
> To: metlist
> 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 Tue 26 Feb 2002 07:19:31 PM PST