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

From: debfred at att.net <debfred_at_meteoritecentral.com>
Date: Thu, 19 Nov 2009 19:36:35 +0000
Message-ID: <111920091936.11684.4B059E43000953DC00002DA422218683269B0A02D29B9B0EBF0B0A9D000D0A0B_at_att.net>

  It seems it depends on what your definition of is, is? If your definition of fusion crust is "that it contains silicates" then by your definition irons cannot have a "fusion crust". They undeniably can have a layer of atmospherically melted then cooled material that formed from the
unaltered underlying iron meteor. It forms in an identical fashion to Fusion crust on stony meteors! Call it peanut butter or blue cheese it doesn't matter to me. Irons have fusion crust in my book.
Regards Fred Olsen
-------------- Original message ----------------------
From: "Martin Altmann" <altmann at meteorite-martin.de>
>
> Unlike in politics and public opinion (and sometimes in science),
> in meteoritics
> it sometimes can be more difficult to adhere to theories/legends,
> if one gets samples in ones very hands, which exhibit the opposite of that,
> the theory postulates.
>
> If you ever had an early picked Sikhote at hand,
> or if you had taken from Andi Gren's Boguslavka slices
> (a fall, who simply hadn't enough time in field, to develop a magnetite,
> wuestite, limonite or whatever -ite weathering crust),
> you would be very surprised.
>
> Cause they don't display that ominous blue-ish flimsy luster, which is often
> reported as fusion crust,
>
> but a thick and fat layer of a discernibly different matter than the
> material beneath, of a dark colour and rough to silky surface.
>
> I never believed in iron fusion crusts neither, but when I got in these
> freshly picked up observed falls, I was disabused.
>
> Main problem in that question is, as it was correctly mentioned here,
> that we simply have so few pristine samples of fresh iron falls and that
> most irons we get in our collections arrive with weathered or artificially
> cleaned surfaces.
>
> Now you may argue about the word "crust" as a (pseudo-)scientific term...
> well for me scientific terms are best, when they keep most of their meaning
> they have in their common use in the language.
> And there crust - meanst for me a layer on the outside of an object.
>
> .....and we have the problem, that there exist these freshly fallen lumps
> with that strange crust. Shall we hide them in the deepest corner of our
> drawers, cause they don't fit in the axiom, that fusion crusts are fusion
> crusts only, when silicates are melting?
>
> Sometimes, if the results don't fit into a theory, one has to think about
> modifying the theory,
>
> Else there wouldn't be no meteorites in our sense at all,
> Nada, Niente, Nix, Nimic,
> cause we all would know that they are products of our Aristotelian
> atmosphere, solified accumulations of terrestrial vapours and probably
> created by lightning strokes,
> wouldn't we?
>
> Best!
> Martin
>
>
>
>
>
>
>
>
> -----Urspr?ngliche Nachricht-----
> Von: meteorite-list-bounces at meteoritecentral.com
> [mailto:meteorite-list-bounces at meteoritecentral.com] Im Auftrag von MEM
> Gesendet: Donnerstag, 19. November 2009 04:31
> An: Meteorites USA; metlist
> Betreff: 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
>
> ______________________________________________
> 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 02:36:35 PM PST