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| Northwest Africa 11860 | |||||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 11860 This is an OFFICIAL meteorite name. Abbreviation: NWA 11860 Observed fall: No Year found: 2017 Country: (Northwest Africa) Mass:  520 g | ||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 22 approved meteorites classified as R3-5. [show all] Search for other: Rumuruti chondrites, Rumuruti chondrites (type 3) | ||||||||||||||||||||||||||||||||
| Comments: | Approved 24 Jul 2018 | ||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 107:
Northwest Africa 11860 (NWA 11860) (Northwest Africa) Purchased: 2017 Classification: Rumuruti chondrite (R3-5) History: A single stone weighing 520 g was found in Morocco prior to 2017. J. Donald Cline and John Sinclair acquired the sample from a meteorite dealer at the Tucson Gem and Mineral Show in February of 2017. Physical characteristics: Sample is black in color, lacks fusion crust, has a rounded flattened shape with shallow broad regmaglypts. A small cut face shows brecciated texture composed of clasts set within abundant small chondrules, which, are visible through the patina. Sample is non-magnetic and only sulfides appear to reflect light on the surface of the cut face. Petrography: Description and Classification (A. Love, App) Sample is a breccia composed of up to 3 cm irregularly shaped, light-orangish to brown-black unequilibrated and equilibrated clasts set within a recrystallized host containing chondrules (avg. dia. 432 μm), fragments and abundant Ni-bearing sulfides and pentlandite. Host contains 40 vol% well-defined, unequilibrated chondrules set within a recrystallized matrix. Unequilibrated clasts contain chemically-zoned, unequilibrated chondrules set within a fine-grained, opaque matrix. Equilibrated clasts contain olivine, low-Ca pyroxene within a recrystallized matrix containing isolated intergrowths of plagioclase with average size 30 μm (Berlin and Stoeffler, 2004). Geochemistry: (A. Love, App) Host: Olivine Fa25.0±14.7 (Fa2.1-48.5), Cr2O3 in ferroan olivine=0.1±0.1, Fe/Mn=74.5 n=22, Low Ca Pyroxene: Fs13.8±9.2Wo1.1±1.0 (Fs2.1-28.1Wo0.3-3.1), N=9. Clast: Olivine Fa 41.8±0.3, Fe/Mn=94.5±2.2, n=5, low Ca Pyroxene: Fs36.0±0.2Wo2.2±0.3, N=3. Classification: Rumuruti chondrite (R3-5, S2, wi-2). Based on Fa and Fe/Mn compositions of olivines, chondrule diameter and texture this sample is a Rumuruti chondrite breccia. Based on the coefficient of variation of olivine within unequilibrated clast, the petrologic subtype is estimated at 3.4 (Bischoff, 2000). Based on presence of low-Ca pyroxene and isolated plagioclase intergrowths within equilibrated clasts, these represent type 5 material. Specimens: PARI holds the main mass. One endcut weighing 20.02 g and a polished thin section are on deposit at App. | ||||||||||||||||||||||||||||||||
| Bibliography: |
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| Data from: MB107 Table 0 Line 0: |
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| Institutions and collections |
App: Department of Geology, 572 Rivers St., Appalachian State University, Boone, NC 28608, United States (institutional address; updated 7 Mar 2013) PARI: Pisgah Astronomical Research Institute 1 Pari Dr Rosman, NC 28772, United States (institutional address; updated 13 Sep 2016) |
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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 8559 approved meteorites from (Northwest Africa) (plus 1896 unapproved names) | ||||||||||||||||||||||||||||||||