Description
Basic informationName: Northwest Africa 10140
This is an OFFICIAL meteorite name.
Abbreviation: NWA 10140
Observed fall: No
Year found: 2015
Country: (Northwest Africa)
Mass: 68 g
Classification
history:
Recommended: Lunar (troct. anorth.)
This is the only approved meteorite classified as Lunar (troct. anorth.).
Search for other: Lunar meteorites
Comments:Approved 31 May 2015
WriteupWriteup from MB 104:
Northwest Africa 10140 (NWA 10140)
(Northwest Africa)
Purchased: 2015 Feb
Classification: Lunar (troctolitic anorthosite)
History: Purchased by Larry Atkins in Morocco in February 2015.
Physical characteristics: Single stone. A saw cut reveals a very fine-grained, light-gray groundmass, crosscut by numerous shock melt veins some up to 3 mm.
Petrography: (C. Agee, UNM) This meteorite is a fine-grained anorthositic troctolite (Prinz and Keil, 1977) with plagioclase (75%), olivine (15%), and low-Ca pyroxene (10%) as dominant silicate phases. There are numerous shock melt domains present, some with quench spinifex textures. Accessory troilite and chromite were observed.
Geochemistry: (C. Agee and N. Muttik, UNM) olivine Fa23.4±2.8, Fe/Mn=90±4, n=11; low Ca pyroxene Fs20.5±1.1Wo3.7±0.9, Fe/Mn=56±6, n=9; plagioclase An97.1±1.0Ab2.7±1.0Or0.2±0.0, n=5; Shock melt (20 μm defocused electron beam, proxy for bulk meteorite composition): SiO2=42.1±0.3, TiO2=0.13±0.04, Al2O3=27.3±3.1, Cr2O3=0.11±0.04, MgO=7.8±2.7, FeO=4.4±1.5, MnO=0.05±0.02, CaO=15.4±1.4, NiO=0.00±0.00, Na2O=0.27±0.03, K2O=0.00±0.00 (all wt%), Fe/Mn=89±35, Mg#=75.9±0.8, MgO+FeO=12.1±4.2 (wt%), n=12.
Classification: Lunar (troctolitic anorthosite) based on Stoeffler et al. (1980).
Specimens: 14 g including a probe mount on deposit at UNM, Larry Atkins holds the main mass.
