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romh

07 Mai 2023 14:29



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mmmm... uite de asta nu stiam. de breccia prima data aud. trebuie sa fi fost ditamai impact ca sa proiecteze bucatile astea. 

Atasez ce am gasit anume despre acest meteorit si imi inchei offtopicul.

Northwest Africa 10203 (NWA 10203)
(Northwest Africa)
Purchased: 2015
Classification: Lunar meteorite
History: Purchased by Aziz Habibi in 2015; reportedly found in near the border between 
Mauritania and Mali.
Physical characteristics: Twenty-seven identically appearing pieces reportedly found together. 
Irregular exterior, no fusion crust. A saw cut reveals a polymict breccia with numerous 
fragmental light and dark clasts.
Petrography: (C. Agee, UNM) This polymict breccia has at least four distinct lithologies. 1) 
unbrecciated olivine gabbro with zoned clinopyroxene (~75%), acicular, plumose plagioclase 
(~15%), olivine (~5%), and minor titanomagnetite; 2) fragmental anorthositic gabbro breccia 
with ~75% plagioclase; 3) fragmental gabbroic breccia with approximately equal proportions of 
plagioclase, pyroxene and olivine; 4) shock melt veins and pools, some of which are vesicular. 
Accessory FeNi-metal, silica, ilmenite, troilite, chromite, and phosphate were observed in the 
fragmental breccias.
Geochemistry: (C. Agee and N. Muttik, UNM) Olivine gabbro: olivine Fa52.9.8±7.1, 
Fe/Mn=100±12, n=6; clinopyroxene Fs31.1±15.8Wo22.1±7.6, Fe/Mn=41±10, n=7; plagioclase 
An89.9±3.8Ab8.9±3.4Or1.1±0.8, n=3; anorthositic gabbro breccia: olivine Fa30.6±3.0, Fe/Mn=104±7, 
n=21; clinopyroxene Fs39.4±15.8Wo21.7±10.9, Fe/Mn=66±11, n=21; plagioclase 
An96.2±0.8Ab3.5±0.8Or0.2±0.1, n=6; gabbroic breccia: olivine Fa40.3±2.9, Fe/Mn=98±5, n=6; 
clinopyroxene Fs35.4±14.3Wo23.3±10.0, Fe/Mn=63±10, n=9; plagioclase An93.0±1.6Ab6.6±1.6Or0.4±0.1, 
n=4; Shock melt (10 μm defocused electron beam, proxy for bulk meteorite composition): 
SiO2=45.1±2.0, TiO2=0.54±0.38, Al2O3=24.3±6.2, Cr2O3=0.21±0.19, MgO=6.5±2.9, 
FeO=8.2±3.8, MnO=0.11±0.05, CaO=14.9±1.9, NiO=0.03±0.07, Na2O=0.49±0.13, 
K2O=0.10±0.03 (all wt%), n=40.
Classification: Lunar (polymict breccia)
Specimens: 24 g including a probe mount on deposit at UNM; Aziz Habibi holds the main mass.


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http://onlinelibrary.wiley.com/doi/10.1111/maps.12930/full