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

From: MEM <mstreman53_at_meteoritecentral.com>
Date: Thu, 19 Nov 2009 17:03:38 -0800 (PST)
Message-ID: <139975.55063.qm_at_web55202.mail.re4.yahoo.com>

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
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Received on Thu 19 Nov 2009 08:03:38 PM PST