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El Médano 100
Basic information Name: El Médano 100
     This is an OFFICIAL meteorite name.
Abbreviation: EM 100
Observed fall: No
Year found: 2011
Country: Chile
Mass:help 1.8 g
Meteoritical Bulletin:  MB 102  (2013)  C2-ung
Recommended:  C2-ung    [explanation]

This is 1 of 25 approved meteorites classified as C2-ung.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), and Ungrouped chondrites
Comments: Approved 1 Mar 2013
Writeup from MB 102:

El Médano 100        24°51’S, 70°32’W

Antofagasta, Chile

Found: 2011 Oct 24

Classification: Carbonaceous chondrite (C2, ungrouped)

History: The meteorite was found in the Atacama desert by Cécile Cournède in October 2011 during a systematic search for meteorites.

Physical characteristics: A single broken stone with fresh black fusion crust and light brown interior.

Petrography: (J. Gattacceca, CEREGE) Small chondrules (average 250 μm) and mineral fragments set in a phyllosilicate-rich matrix. Modal abundances: matrix 70%, chondrules and mineral fragments 23%, sulfides ~1 %. Rare kamacite. Powder x-ray diffraction shows an abundance of serpentine in the matrix.

Geochemistry: Olivine Fa0.6-35.2 (mean 7.3±12.1, N=23), Cr2O3 in ferroan olivine is 0.39 wt.% (n=13), orthopyroxene Fs0.9-8.1Wo2.3-0.9 (mean Fs 3.7±2.8, mean Wo 0.9±0.1 , N=7). Oxygen isotopic compositions: (J. Gattacceca and C. Sonzogni, CEREGE) analysis of a 1.5 mg acid-washed sample by laser fluorination gave δ17O = -10.29; δ18O = -7.59; Δ17O = -6.35 (all per mil). Mag susceptibilty log χ =3.93 (χ in 10-9 m3/kg).

Classification: Carbonaceous chondrite (C2-ung); moderate weathering.

Specimens: 1 gram and a polished section are on deposit at CEREGE. A polished section is at MNHN.

Data from:
  Table 0
  Line 0:
Origin or pseudonym:deflation surface
Date:2011 Oct 24
Mass (g):1.8
Weathering grade:moderate
Fayalite (mol%):7.3±12.1 (N=23)
Ferrosilite (mol%):3.7±2.8 (N=7)
Wollastonite (mol%):0.9±0.1 (N=7)
Magnetic suscept.:3.93
Classifier:J. Gattacceca, A. Hutzler, CEREGE; M. Gounelle (MNHNP)
Type spec mass (g):1
Type spec location:CEREGE
Main mass:CEREGE
Finder:Cécile Cournède
Comments:Submitted by J. Gattacceca
Plots: O isotopes:  
   and collections
CEREGE: CEREGE BP 80 Avenue Philibert, Technopole de l'Arbois 13545 Aix-en-Provence Cedex 4 France, France (institutional address; updated 10 Jun 2023)
MNHNP: Museum National d'Histoire Naturelle, IMPMC-CP52, 57 rue Cuvier, 75005 Paris, France, France; Website (institutional address)
MNHN: Museum National d'Histoire Naturelle, IMPMC-CP52, 57 rue Cuvier, 75005 Paris, France, France; Website (institutional address)
References: Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
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     Recommended::   (24° 51'S, 70° 32'W)

     This is 1 of 2908 approved meteorites from Antofagasta, Chile (plus 10 unapproved names) (plus 1 impact crater)
     This is 1 of 2937 approved meteorites from Chile (plus 13 unapproved names) (plus 1 impact crater)
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