[meteorite-list] LOVINA REVISITED

From: Matthias Bärmann <majbaermann_at_meteoritecentral.com>
Date: Wed, 9 Dec 2009 12:20:25 +0100
Message-ID: <DA4243CE17E1404FA5E2EF36050F52A6_at_thinkcentre>

Hello Darryl,

gosh, so you've to arrange yourself with the fact that perhaps you only have
a part of the spaceship which tried to escape from the sinking Atlantis
instead of a meteorite. In any case: it still looks fantastic.

Best regards,

Matthias

----- Original Message -----
From: "Darryl Pitt" <darryl at dof3.com>
To: "Adam List" <meteorite-list at meteoritecentral.com>
Sent: Wednesday, December 09, 2009 9:15 AM
Subject: [meteorite-list] LOVINA REVISITED


>
> Well, I had an interesting day today....
>
> This morning I met with Roy Clarke, Linda Welzenbach, Cari Corrigan, Glen
> MacPherson, and Tim McCoy at the Smithsonian. During our get- together
> Tim made several observations as to why Lovina could very well not be
> what it has been made out to be---which is to say, a meteorite---and why
> more work must be done.
>
> In Tim's words....
>
> 1) The sulfides are not simply troilite and appear optically to be
> multiple phases, including one that looks like the Ni-rich sulfide
> pentlandite.
>
> 2) Although the presence of the octahedrons has been attributed to
> weathering, the structure of the remainder of the meteorite shows fine
> stringers of sulfide, not large areas that would easily weather out
> leaving such octahedron.
>
> 3) On one polished slice, the sulfides clearly wrap around one of the
> indentations, rather than the cross-cutting relationship one might expect
> from a significantly weathered iron meteorite.
>
> 4) The composition given - high Ni coupled with moderately high Ga and
> Ge - is difficult to reconcile with a meteorite composition. Iron
> meteorites acquire high Ni concentrations through 1 of 3 mechanisms.
> Oxidation simply changes iron to FeO, leaving Ni behind. This can
> produce high-Ni irons with modest Ga and Ge. Nebular condensation can
> also produce high-Ni iron which then melts to form cores in which high-Ni
> iron meteorites form. This process, however, occurs at high temperature
> where the volatile elements Ga and Ge are depleted. Finally, you can
> produce high Ni through fractional crystallization. Ni prefers the solid
> phase when a core crystallizes, so early irons are low in Ni and later
> crystallizing ones are high in Ni. However, Ga and Ge behave opposite of
> Ni, so low Ni irons are high in Ga and Ge and high Ni irons are low and
> Ga and Ge. The published Ga and Ge values are at least a factor of 15
> higher than reported for similar iron meteorites.
>
> 5) The holes exposed in the center of the specimen are not the shape one
> would expect of weathering, but seem circular. Circular vugs are
> commonly produced in slags when gases try to escape.
>
> There was more...including the fact that Indonesia is a nickel-rich
> locality as well as Tim's conclusion that Lovina was most likely a highly
> weathered example of a smelted Ni-rich sulfide.
>
> Sales have been suspended and monies are in the process of being
> returned. Further testing will be done to confirm Lovina's place of
> origin and the results will be posted to the list by mid-January.
>
> I think I'll go see the new Clooney film "Up In The Air." Ohhh---and
> might anyone want an inexpensive 13 kg specimen of Willamette for
> Christmas?!
>
>
> And how was your day? ;-)
>
>
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Received on Wed 09 Dec 2009 06:20:25 AM PST