[meteorite-list] Fusion Crust on Irons--Not

From: Martin Altmann <altmann_at_meteoritecentral.com>
Date: Fri, 20 Nov 2009 02:12:17 +0100
Message-ID: <000301ca697e$80d021c0$07b22959_at_name86d88d87e2>

Hi there,

don't get me wrong, I don't have the intension to convince anybody...

....infact it took me 2 decades or so, until I had had some examples of iron
fusion crust in my hands, which I couldn't ignore any longer :-)

Hmm - let's be patient, I think it's high time for a new iron fall, isn't
it?

Best!
Martin




-----Urspr?ngliche Nachricht-----
Von: meteorite-list-bounces at meteoritecentral.com
[mailto:meteorite-list-bounces at meteoritecentral.com] Im Auftrag von MEM
Gesendet: Freitag, 20. November 2009 02:04
An: meteorite-list at meteoritecentral.com; Greg Stanley
Betreff: Re: [meteorite-list] Fusion Crust on Irons--Not

Because there has been a vacuum in accurate description and cataloging of
flight/ablation features not withstanding Nininger's Surface Features of
Meteorites-- the term "fusion crust" has been adapted to irons but it still
isn't correct. As I mentioned even experts misuse terms and concepts
occasionally.

If I've time later tonight to respond to Martin's post, I'll list a few
possible terms that we need to make operational by defining them so we can
discuss the components of the zone affected by reentry forces.

Elton

--- On Thu, 11/19/09, Greg Stanley <stanleygregr at hotmail.com> wrote:

> From: Greg Stanley <stanleygregr at hotmail.com>
> Subject: RE: [meteorite-list] Fusion Crust on Irons--Not
> To: mstreman53 at yahoo.com, eric at meteoritesusa.com,
meteorite-list at meteoritecentral.com
> Date: Thursday, November 19, 2009, 9:04 AM
>
> Elton:
>
> Take a look - the Smithsonian classifies the meteorites
> from Antarctica and some of the Irons are described as
> having a fusion crust.
>
> Greg S.
>
>
> http://curator.jsc.nasa.gov/antmet/samples/petdes.cfm?sample=MIL07666
>
>
> Sample Number? ??? MIL 07666
> Pairing ??? MIL 07666
> Newsletter ??? 31,2
> Location ??? Miller Range
> Field Number ??? 18159
> Dimensions ??? 5.0 x 2.9 x 1.4
> Weight ??? 96.25
> Original Classification ??? Iron (IIAB)
>
> Macroscopic Description - Cari Corrigan and Linda
> Welzenbach
> This lozenge-shaped meteorite is flight oriented with a
> slight melt flange on the top side. The bottom or flight
> surface is finely pitted, the top side smoother but with
> sporadic, deeper regmaglypts. Fusion crust is 100% and
> exhibits mild oxidation in the form of iridescence and minor
> halos.
>
> Thin Section Description - Tim McCoy, Cari Corrigan and
> Linda Welzenbach
> The meteorite was examined from a cut and etched surface,
> which bisected one end or nose of the specimen. A thin
> fusion crust is preserved over most of the meteorite, and
> gradational heat alteration zone of approximately 1.0-2 mm
> thick underlies the fusion crust on the bottom or flight
> side, and is less than 0.3 mm thick on the top side. A
> prominent coarse a2 structure is found throughout. The
> section exhibits subequant grains ranging up to 1 mm in size
> which meet at 120? triple j
>
>
>
>
>
> ----------------------------------------
> > Date: Wed, 18 Nov 2009 19:30:39 -0800
> > From: mstreman53 at yahoo.com
> > To: eric at meteoritesusa.com;
> meteorite-list at meteoritecentral.com
> > Subject: Re: [meteorite-list] Fusion Crust on
> Irons--Not
> >
> > Stopping in a few minutes to state again that all this
> discussion about fusion crust on irons is right next to
> unicorns postulations. Everyone says that fusion crust on
> irons exists but no one can come up with the proof.
> Non-silicate bearing irons DO NOT/CANNOT have FUSION crust:
> they have a very fragile magentite micro-crystal "film" and
> they have an ablation surface but, they can't by definition
> have a "fusion crust" and no matter whom the expert quoted
> they still do not have a fusion crust. A fusion crust has to
> have a silicate source to for the glass component of the
> crust-- Nada, Nix, No How.
> >
> > Both silicate and non-silicate meteorites have an
> ablated/ablation surface, and they can show flight
> features--but not all meteorites have a fusion crust. I have
> some OCs which have flow lines UNDER the fusion crust
> remnants.
> >
> > If anyone still defends the presence of fusion crust
> on (non-silicate bearing) irons then show me the
> "crust"...can't?..ok show me the glass? .... right then-- no
> photos, no thin sections, no micro graphs???......And while
> there was one close up of an ablated surface showing soft
> wavy lines of briefly melted metal that was aligned to
> aerodynamic vectors--This does not fusion crust make.
> >
> > Unlike in politics and public opinion, in science, no
> matter how often an untruth is repeated it doesn't become
> "truth" by majority belief. But science, being a human
> endeavor, sometimes can find itself "off track" and when it
> does it accepts the error and gets back on track.
> >
> > Elton
> > ______________________________________________
> > http://www.meteoritecentral.com
> > Meteorite-list mailing list
> > Meteorite-list at meteoritecentral.com
> > http://six.pairlist.net/mailman/listinfo/meteorite-list
> ???
> ????????
> ?????? ???
> ?
> _________________________________________________________________
> Windows 7: It works the way you want. Learn more.
>
http://www.microsoft.com/Windows/windows-7/default.aspx?ocid=PID24727::T:WLM
TAGL:ON:WL:en-US:WWL_WIN_evergreen:112009v2
______________________________________________
http://www.meteoritecentral.com
Meteorite-list mailing list
Meteorite-list at meteoritecentral.com
http://six.pairlist.net/mailman/listinfo/meteorite-list
Received on Thu 19 Nov 2009 08:12:17 PM PST