[meteorite-list] deformed etch pattern

From: capricorn89 <capricorn89_at_meteoritecentral.com>
Date: Thu Apr 22 10:02:29 2004
Message-ID: <001501c1cd9f$010e67e0$df36b2d1_at_earthlink.net>

Hi Bernd,

You might be interested in examining CD16 on my website.
http://home.earthlink.net/~capricorn89/rim.htm
Be sure to click for a full screen image. It is what I call a near rim. It
was found due west, at the bottom of the outer talus from the rim, about
12-15 inches deep, so probably tumbled some distance. Found in a region
which was unusually moist. The crust was like a rustball, but very shallow,
and when cleaned, the interior WILL NOT RUST. This is an ultra-thin slice.
It also was almost impossibly hard to cut. On close examination you will
note slippage plains, and what appears to be several lamella crossing an
intrusive vein, they are, in fact, not related. This is the most unusual CD
I have cut, although I have seen this sort of things among research
specimens, but never any commercially available.

By the way, I had permission to hunt. This was back when I was a student in
Meteoritics under Dr. Leonard at UCLA.

Best Wishes,
Ron Hartman
www.meteorite1.com (meteorites)
www.meteorite1.org (membrane boxes)
www.meteorite1.net (cutting, preparation and restoration)








----- Original Message -----
From: Bernd Pauli HD <bernd.pauli_at_lehrer1.rz.uni-karlsruhe.de>
To: <gredfern_at_earthlink.net>
Cc: <Starbits_at_aol.com>; <meteorite-list@meteoritecentral.com>
Sent: Sunday, March 17, 2002 2:06 AM
Subject: [meteorite-list] deformed etch pattern


> Greg Redfern wrote:
>
> > an unusual etch pattern present in a Canyon Diablo Rim. Contrast
> > the nearly featureless RIM etch pattern with that of an etched
> > "plains" Canyon Diablo specimen. The Rim specimen was subjected
> > to great heat from the impact event which essentially erased the
> > Widmanstätten lines.
>
>
> Hi Greg and List,
>
> An interesting specimen! While the Widmanstätten pattern
> is still recognizable, the bandwidth seems to have been
> "squeezed", the lines are bent, the pattern looks much
> more "diffuse" than the unshocked specimen recovered
> from the surrounding plain.
>
> By the way, Buchwald mentions 7 different alteration stages:
>
> BUCHWALD V.F. (1975) Handbook of Iron Meteorites, Volume 2, pp. 390-397:
>
> 1. Original unshocked material
> 2. Shock-hardened masses
> 3. Shock-annealed masses
> 4. Shock-annealed to recrystallization
> 5. Shock-annealed to alpha2-transformation
> 6. Shock-annealed to alpha2-transformation and
> recrystallization of cohenite and schreibersite
> 7. Partly remelted specimens
>
> Another interesting feature of your "rim specimen" is the small thin
> schreibersite skeleton crystals some of which which are oriented at
> a 90° angle in the middle of the picture.
>
>
> Best Sunday
> morning wishes,
>
> Bernd
>
> ______________________________________________
> Meteorite-list mailing list
> Meteorite-list_at_meteoritecentral.com
> http://www.pairlist.net/mailman/listinfo/meteorite-list
Received on Sun 17 Mar 2002 05:32:13 AM PST