[meteorite-list] Deformed Gibeon patterns

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 10:02:30 2004
Message-ID: <3C964095.AB4AFAF9_at_lehrer1.rz.uni-karlsruhe.de>

Anne wrote:

> Vincent's Gibeon is amazing!

Hello Anne and List,

I agree and so is yours, Anne!

> I picked up another odd one in Tucson. It looks as if it was made of
> 3 different pieces: 2 have nice Widmanstatten patterns, but oriented
> differently, and then there is wedge-shape piece with no pattern at
> all. It is now on my site:

> www.impactika.com/meteorites/gibeonslice.html

> How do you explain that one?

I wish I could and I have been waiting here for someone like Eric or
Ron to jump in. Let's start with the easier part of the affair: the two
Widmanstätten patterns which are oriented differently and that Gibeon
slices are so famous for. They represent 2 original taenite grain bound-
aries. A slice with a diameter of about 50 cm may show up to 9 different
taenite grain boundaries and thus as many different orientations of the
Widmanstätten pattern.

As for this wedge-shape piece with no pattern at all, I can only guess
that it is a severely heated, melted, and recrystallized inclusion or it
might be a plessitic field.

Best wishes and ...
waiting for other
list members' comments!

Bernd
Received on Mon 18 Mar 2002 02:31:33 PM PST