[meteorite-list] Ad Weekly Rare Material (Pseudotachylite)

From: Adam Hupe <adamhupe_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:53 2004
Message-ID: <05a801c411d7$3b8613e0$ad971018_at_attbi.com>

Hi John, Alan, Jeff, Bernd and List,

A lot of questions are being asked by scientists and List members alike.

To answer the question, Does this material attract to a magnet? Yes, there
is a strong attraction to a magnet. It does have elemental metal specks
that are perfectly round even at the microprobe level.

Another question was, Why not call it an H7 if it has been recrystallized.
This is because metamorphism did not create the achondritic texture, extreme
shock did. As I said before degrees of metamorphism cannot be measured in
this particular meteorite.

Somebody asked, Does it have vesicles? The answer is no.

An finally it was asked, Why is this not an IMB. Answer, this is not a
breccia.

If you go to the following link under Meteorite Classification Services and
look at the H section under Ordinary Chondrites and scroll down to NWA 2058
you will see some formal data regarding this find.

http://jan.ucc.nau.edu/~wittke/Microprobe/Probe.html

It is good to see a great deal of interest concerning this meteorite. I
asked many questions myself in order to try to understand this particular
meteorite. Hopefully my translation of what I have been told carries
through in a way that proves how interesting this recent find really is.

All the best,

Adam Hupe




----- Original Message -----
From: <j.divelbiss_at_att.net>
To: "Adam Hupe" <adamhupe_at_comcast.net>
Cc: <meteorite-list_at_meteoritecentral.com>
Sent: Tuesday, March 23, 2004 10:55 PM
Subject: Re: [meteorite-list] Ad Weekly Rare Material (Pseudotachylite)


> Adam,
>
> Does this material attract to a magnet? Being an H, I suppose it
does...but maybe not.
>
> John
>
> > Dear List Members,
> >
> > We would like to introduce NWA 2058 an extremely odd meteorite called a
> > plain "H" with no subclass. It is also known in the scientific circles
as a
> > Psuedotachylite. Through a great deal of study NAU and the UW determined
> > this Psuedotachylite originated from the H chondrite parent body. It
was
> > not thought of as being a meteorite at first because it looks completely
> > different than anything that had been seen before. Some may ask, How
come
> > no metamorphic subclass? It is the most shocked chondrite yet
discovered
> > with no chondritic features that can be measured for metamorphism
meaning no
> > metamorphic subclass can be assigned. Another problem was what to call
it,
> > an achondrite from a chondritic parent body or simply an H with the
> > qualifier Psuedotachylite or melt rock. This unique material has caused
a
> > stir in the scientific community with laboratories requesting samples
which
> > will make this a very well studied meteorite.
> >
> > Here is a brief description of this one-of-a-kind meteorite:
> >
> > NWA 2058 is an H (Pseudotachylite), Fa 17.1-18.4, S6 plus, W2/3
chondrite
> > found in Northwest Africa 2001. This unique meteorite cannot be
subclassed
> > because of extreme mylonitization. Mylonitization is fusion of crushed
rock
> > under high temperature by frictional heating. In other words, this
> > meteorite was formed by a hypervelocity impact on the surface of an
asteroid
> > and cooled within milliseconds as it was ejected out into space. During
the
> > impact event it was crushed and sheared simultaneously creating
subparallel
> > veins in the direction of the material flow connecting elongated
> > metal-sulfide nodules, talk about interesting! Relic grains show
evidence
> > of high strain rates, partially granulated clasts with undulatory
> > extinction, in contrast to shock features. The matrix consists mostly
of
> > recrystallized olivine. The round objects are not chondrules but are
impact
> > melted and quenched metal sulfide. Five stones with unusually smooth
fusion
> > crusts were found adding up to 80 grams TKW. So far 17.1 grams has been
> > provided to science and a great deal was lost to cutting and polishing
> > leaving very little for collectors. Since this unusual meteorite is
still
> > currently under study and other laboratories are requesting samples we
plan
> > on preserving a good portion in our collection for future studies.
> >
> > I brought up that there are Hs listed with no subtype and was told this
is
> > not the same situation as with this special meteorite. The reason for
the
> > others is simply incomplete information. In some cases there was not
enough
> > material to subclassify and in other cases the classifications were
never
> > completed. In yet other cases the material was lost through time. The
> > classification on this unique meteorite is complete making it the only
plain
> > H that has been fully classified with supporting data.
> >
> > Since we have no idea what something like this is worth we will let the
> > market decide by starting over a dozen prepared specimens out at just 99
> > cents and see where they end up. Hopefully, the proceeds will be enough
to
> > offset lab fees we incurred during the study of this material. This new
> > meteorite is so dark that is very difficult to photograph the features.
I
> > will try to take some photomicrographs with a digital microscope in the
next
> > few days. To see this new meteorite and over 100 interesting auctions
check
> > out the ebay link below:
> >
> > http://members.ebay.com/aboutme/meteoritelab/
> >
> > Thank you for looking and if you are bidding, good luck.
> >
> > Adam and Greg Hupe
> > The Hupe Collection
> > Team LunarRock
> > IMCA 2185
> >
> >
> >
> > ______________________________________________
> > Meteorite-list mailing list
> > Meteorite-list_at_meteoritecentral.com
> > http://www.pairlist.net/mailman/listinfo/meteorite-list
Received on Wed 24 Mar 2004 02:35:57 PM PST