[meteorite-list] Irons DON'T form Fusion Crust's - yes they DO

From: Eric Twelker <twelker_at_meteoritecentral.com>
Date: Sun, 07 Jan 2007 09:53:17 -0900
Message-ID: <C1C6738D.2BC09%twelker_at_alaska.net>

The only problem here is that EMan has changed the definition of "glassy"
to make his argument work. Here is what Princeton says:

Adjective
    ? S: (adj) glassy (resembling glass in smoothness and shininess and
slickness) "the glassy surface of the lake"; "the pavement was...glassy with
water"- Willa Cather
    ? S: (adj) glassy, glazed ((used of eyes) lacking liveliness) "empty
eyes"; "a glassy stare"; "his eyes were glazed over with boredom"
    ? S: (adj) glassy, vitreous, vitrified ((of ceramics) having the
surface made shiny and nonporous by fusing a vitreous solution to it)
"glazed pottery"; "glassy porcelain"; "hard vitreous china used for plumbing
fixtures"

I'll go with common sense on this one. Fusion crust is the fused rind on
the outside of a meteorite. And people whose eyes are "glassy" don't all
have glass eyes.

    Eric Twelker

> Hello Listoids, Svend
> --- "Dr. Svend Buhl" <info at niger-meteorite-recon.de>
> wrote:... I do not agree that the Glossary of
> Geology of the American Geological Institute is a
> sound reference for nomenclature and terminology of
> meteorites.
>
> GIST: For those that don't want to read the details, I
> am asserting that even thought there is something to a
> complex ablation surface on iron meteorites, the
> widely accepted and published definition of fusion
> crust states that it is a glassy coating, which would
> exclude the coatings on irons from being called fusion
> crusts. I also call for a revision of the definition
> to overcome that exclusion.
>
> Thank you for joining the debate, Svend. Nice to know
> someone has access to Buckwald's hand book. It is good
> we can have academic debates and not attack the
> messengers. I trust you will accept this as a
> discussion of a deficiency in the literature and not a
> disregard for yourself nor V.F. Buchwald. I believe
> the use of the term "fusion crust" is weakly founded
> in literature in general for the ablation surface is
> far more complicated than the simplification of
> a"glassy melt". This need not be an"angels on the
> head of a pin" argument for I feel that a revised
> definition dropping "glass/glassy" else making a
> distinction for the rind on iron meteorites being
> different is long overdue.
>
> It is human nature to tend to believe the references
> we have in our possession over those not in our
> possession. Unfortunately, Buchwald's work at
> $2000-$3000 isn't available to most institutions,
> researchers, nor collectors. There is also no easily
> found evidence that he attempted to change the
> definition of fusion crust to include the rind that
> forms on irons. Rather he adopted a concept already in
> use. An opinion by a distinguished researcher in 1975
> may open a door to a revision of the definition but
> the accepted definition in literature simply does not
> address the rind/coating/glaze occurring on iron
> meteorites. We need a revised definition for fusion
> crust however, I've no idea who would be the crusade
> leader.
>
> The reality remains that the vast
> citations/definitions in world literature still
> specifically state "glass" as a component of fusion
> crust when composition is discussed. Without an
> uniform operational definition that is accepted
> throughout the research/education community any
> discussion--even by Buchwald, has a fatal flaw
> semantically speaking. As it is, I am not incorrect in
> asserting as I did in previous posts, according to
> widely published definition, there is no occurrence of
> fusion crust on iron meteorites. There is something,
> yes, but it isn't covered by the literature at large.
>
> Exhibits cited from the web:
>
> NASA
> Fusion Crust: Dark glassy coating on the surface of a
> meteorite..
> <http://ares.jsc.nasa.gov/Education/Activities/ExpMetMys/Glossary.pdf>
>
> Typical definition found at Institutions of higher
> learning:
> FUSION CRUST ? Melted glassy exterior of a meteorite
> that forms when it passes through Earth?s
> atmosphere... ...fuses to form a thin, glassy skin
> which envelopes the whole meteorite.
>
> <http://www4.nau.edu/meteorite/Meteorite/Book-GlossaryF.html>
>
> Planetary Science Research Discoveries (PSRD)
> Fusion crust: The glassy, melted rind on a meteorite
> that forms when the rock passes through the Earth's
> atmosphere.
> <http://www.psrd.hawaii.edu/PSRDglossary.html>
>
>
> Britannica: any meteorite consisting mainly of iron,
> usually combined with small amounts of nickel. When
> such meteorites, called irons, fall through the
> atmosphere, a thin, black crust of iron oxide may form
> that quickly weathers to rust.
>
> Elton aka Eman
>
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Received on Sun 07 Jan 2007 01:53:17 PM PST