[meteorite-list] EETA 79001 and the Martian Atmosphere

From: Richard Montgomery <rickmont_at_meteoritecentral.com>
Date: Wed, 9 Feb 2011 11:42:37 -0800
Message-ID: <F577B9298D99401490051674C9AEEFEA_at_bosoheadPC>

Hi List. (Sorry if this is a duplicate post.) I have the remnants of a
550gr Brahin slice that definitely has bubbles in the olivine in a few
spots. Any comments?


----- Original Message -----
From: <cdtucson at cox.net>
To: "Martin Altmann" <altmann at meteorite-martin.de>;
<meteorite-list at meteoritecentral.com>
Sent: Wednesday, February 09, 2011 11:24 AM
Subject: Re: [meteorite-list] EETA 79001 and the Martian Atmosphere


> 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 02:42:37 PM PST