[meteorite-list] Met Bulletin Update - Mreïra is official.

From: Galactic Stone & Ironworks <meteoritemike_at_meteoritecentral.com>
Date: Sat, 27 Jul 2013 11:02:44 -0400
Message-ID: <CAKBPJW8aONuvcy1uN5HH2p87K1FaOzb6w+twRE6QWRmo7ANr=A_at_mail.gmail.com>

Hi Collectors,

The new fall from Dec 16, 2012 over Mauritania has been approved.

Write-up :

Mre?ra 25?57.550?N, 10?57.615?W
Tiris Zemmour, Mauritania
Found: Dec 2012
Classification: Ordinary chondrite (L6)

History: According to Ait Hiba Abdelhad, a fireball was seen in the
afternoon sky on December 16, 2012, several school children saw the
fireball explode and detonations were heard near the village of
Mehaires, Western Sahara. Pieces were recovered approximately 40 miles
south of Mehaires, near Mre?ra, Mauritania, only a few days after the
event. The strewn field is in the area called "Stailt Omgrain", which
is a local nomadic name. This is south of Mehaires and north of the
mountain "Galbe lahmar". Therefore this is a possible fall associated
with the fireball of December 16, 2012.

Physical characteristics: The largest single piece weighed 602 grams
and was completely covered with fresh fusion crust. A total of
approximately 6 kg of freshly crusted stones were recovered.

Petrography: (C. Agee, UNM) Microprobe examination of two polished
surfaces shows brecciation and numerous fractured silicate grains,
scattered equilibrated chondrules, shock-melt pockets, kamacite,
troilite, and merrillite. Fresh, vesiculated fusion crust ~200 ?m
thick.

Geochemistry: (C. Agee and L. Burkemper, UNM) Olivine Fa24.4?0.2,
Fe/Mn= 47?3, n=8; low-Ca pyroxene Fs20.3?0.1Wo1.5?0.1, Fe/Mn= 28?1,
n=7; plagioclase Ab82.7?2.0An10.4?0.6Or6.8?1.4, n=4.

Classification: Ordinary chondrite (L6), weathering grade (W0), shock grade (S6)

Specimens: 91.2 g including a fusion-crusted complete stone and a
microprobe mount on deposit at UNM, MtMorgan holds the 602 g main mass
and another 400 g of complete stones, Gary Fujihara holds 335 g of
fusion crusted individuals, the largest being 104 g.


Link - http://www.lpi.usra.edu/meteor/metbull.php?code=57653

Best regards and happy huntings,

MikeG

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Received on Sat 27 Jul 2013 11:02:44 AM PDT