[meteorite-list] Met Bulletin Update - Jbilet Winselwan CM2 is official.

From: Galactic Stone & Ironworks <meteoritemike_at_meteoritecentral.com>
Date: Wed, 21 Aug 2013 11:56:48 -0400
Message-ID: <CAKBPJW8isSKTYRDOCp_nUGwysB4U_Hb6f3BOS+Zv=2tR0O+W8Q_at_mail.gmail.com>

Hi Bulletin Watchers,

Congratulations to the consortium of hunters, dealers, and scientists
who pooled together and got this one official under single name and
locality. :)

Jbilet Winselwan CM2 (link, write-up follows) -
http://www.lpi.usra.edu/meteor/metbull.php?code=57788


Jbilet Winselwan
26?40.044?N, 11?40.637?W
Morocco/Western Sahara
Found: 24 May 2013
Classification: Carbonaceous chondrite (CM2)

History: (H. Chennaoui Aoudjehane, M. Aoudjehane, A. Laroussi, A.
Bouferra) In early June 2013, A. Bouferra, a meteorite hunter from
Smara, reported a new carbonaceous chondrite that had been found close
to Smara. Due to its proximity to Smara (7 km), many meteorite hunters
visited the area in the summer of 2013.

Physical characteristics: Total mass is estimated about 6 kg, with
small and complete pieces between 3 and 10 g, a few medium-sized
pieces 10 to 200 g and rare big pieces >200 g. The largest sample is
~900 g. Fresh looking fusion is crust present on many fragments. Some
fragments are wind ablated. Some cracks contain secondary, crystalline
alteration products. Interior of stones is black and peppered with
chondrules.

Petrography: (R. Hewins, MNHNP, L Garvie, ASU). The meteorite contains
chondrules and fragments of Types I and II. These include BO-PO,
formerly metal-rich, and olivine-pyroxene Type I chondrules. Type II
chondrules with forsterite relict grains are present. There are
regions packed with chondrule material and coarse PCP, and zones with
scattered chondrule material in fine-grained matrix. Chondrule sizes
range up to 1.2 mm, though most are around 200 ?m. A few CAIs are 800
?m. Powder x-ray diffraction shows a strong 0.7 nm peak for
serpentines, a broad but weaker peak around 1.3 nm corresponding to
smectites, and a weak broad peak consistent with tochilinite.

Geochemistry: (R. Hewins, MNHNP) Olivine is Fa0.98?0.44 and Fa25-40.
Pyroxene is Fs2.6?1.5 and Fs40-61. Rare kamacite with 5.8 wt% Ni is
present. (P. Cartigny, IPGP) The oxygen isotopic compositions of two
pieces were determined as ?18O 3.811?0.09 and 5.851?0.016, ?17O
-2.446?0.040 and -0.601?0.026, respectively. ?17O values are -4.441
and -3.663, mean -4.052.

Classification: The oxygen isotope compositions, petrography and
mineral compositions are all consistent with CM2

Specimens: 17.8 g MNHNP, 17.4 g FSAC provided by L. Labenne, 20 g UNM
provided by G. Fujihara, 122 g ASU provided by Farmer. Other
collection masses include: Farmer 2.6 kg, Labenne 1.6 kg, T.
Jakobowski 512 g, G. Fujihara 358 g, M. Ouzillou 173 g.

State/Prov/County: Saguia el Hamra
Date: 24 May 2013
Latitude: 26?40.044'N
Longitude: 11?40.637'W
Mass (g): about 6000
Pieces: Many
Class: CM2
Shock stage: S0
Weathering grade: W1
Fayalite (mol%): 0.98?0.44 and 25-40
Ferrosilite (mol%): 2.6?1.5 and 40-61
Wollastonite (mol%): 1.1?0.1
Magnetic suscept.: 4.05-4.15
Classifier: B. Zanda, R. Hewins, MNHNP; H. Chennaoui Aoudjehane, FSAC
Type spec mass (g): 177 g total
Type spec location: MNHNP, FSAC, ASU
Main mass: See text
Finder: H. Chennaoui Aoudjehane, M. Aoudjehane, A. Laroussi, A. Bouferra
Comments: Submitted by H. Chennaoui Aoudjehane


Best regards and happy huntings,

MikeG

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Received on Wed 21 Aug 2013 11:56:48 AM PDT


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