| MetSoc Home Publications Contacts |
|
||
|
||
| Northwest Africa 13135 | |||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Basic information | Name: Northwest Africa 13135 This is an OFFICIAL meteorite name. Abbreviation: NWA 13135 Observed fall: No Year found: 2018 Country: Morocco Mass:  58.3 g | ||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 605 approved meteorites classified as Ureilite. [show all] Search for other: Achondrites, Ureilites | ||||||||||||||||||||||||||||||
| Comments: | Approved 9 Feb 2020 | ||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 109:
Northwest Africa 13135 (NWA 13135) Morocco Purchased: 2018 Apr Classification: Ureilite History: One piece with a weight of 58.3 g was purchased by Sergey Vasiliev from a Moroccan meteorite dealer in Zagora in 2018. Physical characteristics: Dark-brown individual with well preserved fusion crust. The interior of the meteorite is grayish, with granular texture. Petrography: (P. Yu. Plechov, FMMR). Petrographic observation of a polished section shows that the meteorite is composed of coarse-grained olivine (up to 2 mm) and fine pigeonite (size up to 400 µm). Olivine grains are Fo80.5 and elevated CaO (0.38±0.05 wt.%, n=13) and Cr2O3 (0.78±0.06 wt.%, n=13) abundances. No high-Ca pyroxene or orthopyroxene were observed. Pigeonite has 5.5-6.0 wt.% CaO. Saw-tooth, carbon-rich veins cross the meteorite. Veins or vein fragments with thicknesses of about 50 μm are composed by graphite (without diamond). Thinner veins of about 20 μm thickness contain kamacite with schreibersite rims and troilite-daubreelite intergrowths. Narrower veins, up to 10 μm in thickness, are mostly filled with iron hydroxides. Olivines have reduced rims with very tiny (<<1 µm) drops of iron (without Ni) and more magnesium than the cores (up to Fo87.8). These features are typical for olivine-pigeonite, main group ureilites (monomict ureilites). Irregularly shaped cracks and the absence of other features of impact indicate the sample has a very weak shock stage. Kamacite is partially replaced by iron hydroxides, whereas sulfides and silicates are fresh. Geochemistry: Mineral composition and Geochemistry: EDS-WDS analyses (P. Yu. Plechov, FMMR). Ureilite consists of olivine Fa19.5±0.13, CaO 0.38±0.05 wt.% and Cr2O3 0.78±0.06 wt.% (N=13), pigeonite Fs16.10±0.27Wo11.58±0.26 (N=13), kamacite (in wt.%): Fe-94.22, Ni-4.57, troilite, daubreelite (in wt.%): Fe-52.54, S-32.66, Cr-7.96, schreibersite or nickelphosphide, graphite, iron and hydroxides. Classification: (P. Yu. Plechov, FMMR). Ureilite. Specimens: Sergey Vasiliev holds main mass 44.7 g. 13.6 g FMMR. | ||||||||||||||||||||||||||||||
| Data from: MB109 Table 0 Line 0: |
|
||||||||||||||||||||||||||||||
| Institutions and collections |
FMMR: Fersman Mineralogical Museum, Leninskiy prospekt 18 korpus 2, Moscow, Russia, 119071, Russia; Website (institutional address; updated 24 Feb 2018) |
||||||||||||||||||||||||||||||
| Catalogs: |
| ||||||||||||||||||||||||||||||
| References: | Published in Meteoritical Bulletin, no. 109, in preparation (2020)
| ||||||||||||||||||||||||||||||
| Photos: |
| ||||||||||||||||||||||||||||||
Geography:
|
Statistics: This is 1 of 1852 approved meteorites from Morocco (plus 24 unapproved names) (plus 1 impact crater) | ||||||||||||||||||||||||||||||