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Northwest Africa 12002 | |||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 12002 This is an OFFICIAL meteorite name. Abbreviation: NWA 12002 Observed fall: No Year found: 2017 Country: Morocco Mass: 5 g | ||||||||||||||||||||||||
Classification history: |
This is 1 of 318 approved meteorites (plus 2 unapproved names) classified as Martian (shergottite). [show all] Search for other: Martian meteorites | ||||||||||||||||||||||||
Comments: | Approved 16 Oct 2018 | ||||||||||||||||||||||||
Writeup |
Writeup from MB 107:
Northwest Africa 12002 (NWA 12002) Morocco Purchased: 2017 Classification: Martian meteorite (Shergottite) History: Purchased from a France-based Moroccan dealer in 2017, via internet. Physical characteristics: The main mass is a single, green-gray chip with adhering red-brown dust and fusion crust on one side. Petrography: (C. Herd and L. Tunney, UAb; E. Walton and H. Jurak, MacEwan U) Optical and microprobe examination of a polished thin section shows low-Ca pyroxene oikocrysts up to 3.5 mm in longest dimension enclosing equant, rounded olivine and subhedral rounded to euhedral chromite chadacrysts. Assemblages of plagioclase, low- and high-Ca pyroxene, Ti-bearing chromite comprise the non-poikilitic areas. Shock deformation and transformation effects in host rock minerals include strong mosaicism of olivine and pyroxene, mechanical twinning in pyroxene and complete transformation of plagioclase to maskelynite. Small, isolated pockets of shock melt are heterogeneously distributed throughout the host rock, from which needles of stishovite have crystallized. Thin black veinlets of quenched shock melt cut across and displace igneous minerals. Geochemistry: (C. Herd and L. Tunney, UAb) Data obtained by EMP examination of carbon-coated thin section: Olivine Fa39.7±1.5 (range Fa34.1-41.2), FeO/MnO = 51 (n=35); low-Ca pyroxene Fs29.4±2.4Wo10.6±3.3 (range Fs24.6-32.8Wo2.8-16.6), FeO/MnO = 30 (n=23); high-Ca pyroxene Fs18.4±1.2Wo33.8±2.2 (range Fs16.5-20.7Wo31.2-38), FeO/MnO = 25 (n=9); plagioclase An50.9±4.8Or2.8±1.3 (range An40.6-56.9Or1.4-6.2) (n=20). Chromite range TiO2 = 0.9-17 wt% (n=16). Classification: Martian (shergottite, poikilitic) Specimens: Type specimen of 3.2 g, including one thin section, at UAb. 1 g with M. Ouzillou. | ||||||||||||||||||||||||
Data from: MB107 Table 0 Line 0: |
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Institutions and collections |
UAb: 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB, T6G 2E3, Canada, Canada; Website (institutional address; updated 17 Oct 2011) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 107, MAPS 55, 460-462
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Geography: |
Statistics: This is 1 of 2049 approved meteorites from Morocco (plus 31 unapproved names) (plus 1 impact crater) | ||||||||||||||||||||||||
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Revision history: |
This lists important revisions made to data for this record.
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