[meteorite-list] EETA 79001 and the Martian Atmosphere

From: cdtucson at cox.net <cdtucson_at_meteoritecentral.com>
Date: Wed, 9 Feb 2011 14:24:27 -0500
Message-ID: <20110209142427.XNTKO.339513.imail_at_fed1rmwml44>

Martin,List,
Interesting that you mention bubbles in Maskelynite.
I have a great picture taken by Tom Phillips of an amazing "River Of Maskelynite With Bubbles"
Although this is from an unclassified meteorite it does check out pretty well both visually in thin section but, the chemistry is also correct for either a Lunar or a Martian meteorite,
I'm sure Blain won't mind me mentioning that;
At this Tucson Gem Show Blain Reed has acquired an amazing piece of hardware.
It is called an XRF for X-ray Florescence. This is a hand held portable gun like instrument that when held up to the rock gives you an average of the chemistry it sniffs out of the rock.
Blain was kind enough to use this machine to collect reading from known Lunar rocks in his collection (this way he knows they are in fact Lunar's) With this info he can compare the Known data with new Candidates. This for a small fee and it only takes about a minute. AMAZING . Blain rocks.
In this way he has determined that this rock I show here with the "river Of Maskelynite and Bubbles" has a very good chance at being either Lunar of Martian. Apparently they are quite similar in this way.
Although, The Numbers are dead on Lunar for this one. .
Not only are the bulk amounts correct but so, are the Ratios. Especially the Fe/ Mn and so forth.
Please see the attached pics and share your opinion.
Any Scientists out there want to take a look?
I also have another that Tom Phillips photographed that also checks out both Chemically and petrographically as Lunar or Martian but, with no visible river yet? It looks like mostly Olivine? But this ones Fe/Mn is definitely in the Martian Range. Very Cool.

 http://www.flickr.com/photos/13030472 at N07/?saved=1

Any and all comments welcome.
Email for more pics.
Best regards,
Carl
Carl or Debbie Esparza
Meteoritemax


---- Martin Altmann <altmann at meteorite-martin.de> wrote:
> Hi Walter,
>
> only a remark... for not being the same thing like with the ominous purple
> halite-crystals containing liquid water in Zag,
> which are described in literature - but so far noooooone of the collectors
> ever found one in any of their 175kgs of slices... :-)
>
> Those inclusions in the Martian shock glasses - you can really have them as
> a collector too!!
>
> The fresh-shergottite-series - NWA 2975/2986/4766 seq..
> there the maskelynite is still so fresh, that it is translucent.
> So it's possible without special equipment and special preparation to spot
> these inclusions in the maskelynite with a simple microscope under low
> magnification in cut surfaces.
>
> And you know what? Here and there these maskelynite patches contain little
> bubbles!
>
> A while ago a collector loaded up a photo he made from such a bubble out of
> that NWA-series in the German forum.
>
> Fascinating isn't it?
>
> So, dear collectors, I'm sure many of you have samples form that Martian,
> let's hunt for bubbles!
>
>
> Best!
> Martin
>
> -----Urspr?ngliche Nachricht-----
> Von: meteorite-list-bounces at meteoritecentral.com
> [mailto:meteorite-list-bounces at meteoritecentral.com] Im Auftrag von Walter
> Branch
> Gesendet: Mittwoch, 9. Februar 2011 04:31
> An: MeteorList
> Betreff: [meteorite-list] EETA 79001 and the Martian Atmosphere
>
> Hello Everyone,
>
> I feel like an idiot.
>
> I know that trapped atmospheric gases have been found in some martian
> meteorites but for some unexplained reason, I had always thought that the
> gases had been incorporated in the rock at the time of formation. I always
> wondered how gases from the martian atmosphere could have been trapped in a
> rock at the time it formed, particularly an igneous rock in an underground
> magma chamber.
>
> Well, thanks to William Cassidy, the man who founded ANSMET, I now realize
> my assumption was wrong. Cassidy makes it clear that gasses became trapped
> in martian rocks at the time of the impact which launched the rock from the
> surface. The rather lengthy quote below is from Cassidy's book "Meteorites,
> Ice and Antarctica" an excellent book (see more after the quote).
>
> >From pages 119-121
>
> EETA 79001 was an important find for another reason. It contained proof that
>
> SNC meteorites come from Mars. This meteorite had been highly shocked during
>
> the impact that ejected it from the martian surface, and one of the shock
> effects was to produce pods of glass that had been melted from the
> constituent minerals of the meteorite by the transient heating generated by
> shock pressures. The melts that were formed were partly injected along
> cracks in the rock and partly retained as molten beads at the sites where
> they formed. Cooling occurred immediately behind the shock wave and the
> beads were chilled to glass before they could crystalize. Apparently the
> crater forming asteroid had built up a lense off compressed atmosphere in
> front of it during it's lengthy trajectory toward the surface of the planet.
>
> When it struck the surface it injected highly compressed air into the target
>
> rock, and some of this was trapped in the shock-melted inclusions. We know
> the composition of the martian atmosphere from measurements made by Viking
> Landers I and II. When some of the glass inclusions were picked out of EETA
> 79001 and remelted, the gave up their dissolved gases. These gasses when
> analyzed and corrected for slight terrestrial contamination, contained
> nitrogen and carbon dioxide in the same abundances as the atmosphere of
> Mars; they also had isotopes of argon, neon, , krypton, and xenon in the
> same abundances as does the martian atmosphere. This neat bit of detective
> work by a number of workers, for the first time tied a SNC meteorite
> directly to the planet Mars and, through this meteorite, to all the other
> meteorites.
>
> I love Cassidy's book. If you like meteorites in general, martian and lunar
> meteorites (like me) and are curious about the ANSMET program and you don't
> have a copy of this book, you are really missing out. The book is a gold
> mine of information regarding ANSMET. It is very readable, technical in some
>
> places, humorous in others and poignant in others. Some books I love holding
>
> and reading and this is one of those books. It is hardbound with glossy
> pages and nicely illustrated. I like the physical proportion of the book and
>
> I even like the dust jacket (I usually abhor dust jackets).
>
> Anyway, many thanks to Dr. Cassidy for clearing that up with me and thanks
> for writing such a wonderful book.
>
> -Walter Branch
>
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Received on Wed 09 Feb 2011 02:24:27 PM PST