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| El Médano 200 | |||||||||||||||||||||||||||||||||||||||
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| Basic information | Name: El Médano 200 This is an OFFICIAL meteorite name. Abbreviation: EM 200 Observed fall: No Year found: 2011 Country: Chile Mass:  2.4 g | ||||||||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 3 approved meteorites classified as C3. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), and Ungrouped chondrites | ||||||||||||||||||||||||||||||||||||||
| Comments: | Approved 12 Sep 2013 | ||||||||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 102:
El Médano 200 ~24°51’S, ~70°32’W Antofagasta, Chile Found: 2011 Oct 29 Classification: C3 History: A single stone was found in the Atacama desert by Pierre Rochette in October 2011. Physical characteristics: A single 2.4 g stone with fusion crust. The interior is uniformly dark and porous. Petrography: (J. Gattacceca, CEREGE) The meteorite consists of small chondrules (mostly type I, often with a fine-grained dark rim), chondrule fragments, mineral fragments (up to one mm) in a fine-grained matrix. Modal abundances: matrix 55%, chondrules and mineral fragments 45%. Chondrule mean size is 130±80 μm (N=41). Some chondrules show Fe diffusion rims in the olivine (~2 μm thick). Presence of dusty olivine. Abundant assemblages of magnetite and sulfides (troilite) up to 100 μm. Rare metal. Based on magnetic measurements, magnetite content is estimated to ~19 wt.% under the form of fine grains in the matrix. Powder XRD pattern lacks phyllosilicate reflections. Raman spectra of the matrix (L. Bonal, IPAG) suggest minimal thermal metamorphism. IR spectra of the matrix (L. Bonal, IPAG) suggest some aqueous alteration and the presence of carbonates. Geochemistry: Olivine Fa0.3-69.5 (mean 22.7±23.6, PMD Fa = 94%, N=39). Cr2O3 in ferroan olivine is 0.36±0.24 wt.% (N=30). Orthopyroxene Fs1.6±0.5Wo0.7±0.4 (N=7). Ca-rich pyroxene Fs1.5-17.4Wo42.3-28.1 (N=3). Three metal analyses give Fe46.5±3.5Ni53.5±2.3 indicating Ni-rich taenite or tetrataenite. Oxygen isotopic compositions: (J. Gattacceca and C. Sonzogni, CEREGE) analysis of a 1.5 mg acid-washed sample by laser fluorination gave δ17O = -5.15, δ18O = -1.74, Δ17O = -4.25 (all per mil). Mag susceptibility log χ =5.08 (χ in 10-9 m3/kg). Classification: C3 with affinities to CO3. Specimens: One gram and a polished section at CEREGE. Main mass with CEREGE. | ||||||||||||||||||||||||||||||||||||||
| Data from: MB102 Table 0 Line 0: |
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| Plots: | O isotopes: | ||||||||||||||||||||||||||||||||||||||
| Institutions 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) IPAG: Institut de Planétologie et d’Astrophysique de Grenoble 414, Rue de la Piscine Domaine Universitaire 38400 St-Martin d’Hères , France (institutional address; updated 1 Aug 2013) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
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Geography:
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Statistics: This is 1 of 3632 approved meteorites from Antofagasta, Chile (plus 12 unapproved names) (plus 1 impact crater) This is 1 of 3661 approved meteorites from Chile (plus 13 unapproved names) (plus 1 impact crater) | ||||||||||||||||||||||||||||||||||||||
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