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| Acfer 374 | |||||||||||||||||||||||
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| Basic information | Name: Acfer 374 This is an OFFICIAL meteorite name. Abbreviation: There is no official abbreviation for this meteorite. Observed fall: No Year found: 2002 Country: Algeria Mass:  118 g | ||||||||||||||||||||||
| Classification history: |
This is 1 of 642 approved meteorites (plus 1 unapproved name) classified as CO3. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), CM-CO clan chondrites, and CO chondrites | ||||||||||||||||||||||
| Comments: | Approved 3 Feb 2006 | ||||||||||||||||||||||
| Writeup |
Writeup from MB 90:
Acfer 374 26°36′52′′N, 04°03′18′′E Acfer region, Libya Find: November 2002 Carbonaceous chondrite (CO3) History: Seven small fragments, weighing 118 g in total, were found in the Acfer area of Libya by an Italian dealer. The largest mass weighs 30 g. Physical Characteristics: (V. Moggi-Cecchi, A. Salvadori, and G. Pratesi, MSP) The hand specimen has an outer surface that is brown-red while the interior is darker. Petrography: Chondrules range in size from 30 to 450 µm (mean 110 µm). Chondrules textural types: GO to GOP = 61%, PO = 17%, GOP = 12%, radial pyroxene (RP) = 4%, C = 4%, POP = 1%, and BO = 1% (all vol%). Matrix/ chondrules ratio is ~0.5. Chondrules are set in a very fine-grained matrix composed of olivine, phyllosilicates, and pyroxene. Calcium-rich, aluminum-rich inclusions (CAIs), and amoeboid olivine inclusions (AOIs) account for about 10 vol% of the meteorite. Opaque phases (6–8 vol%) include Fe,Ni alloys, troilite, pentlandite, and pyrrhotite. Rare grains of awaruite (Ni2Fe), tetrataenite (FeNi), schreibersite, and nickel phosphide are present. Geochemistry: (SEM and EPMA) Olivine composition is variable (Fo55–99, mean Fo94, n = 26 [n refers to the number of analyses performed]), with narrow compositional ranges in type I chondrules, mainly GO (Fo95–100, mean Fo97.1) and wider in type II (Fo55–100). Mean Cr2O3 content in 10 MgO-poor olivines (FeO > 2 wt%) is 0.35 wt%. Olivine in AOIs is Fo-rich, Fo96–100. Low-Ca pyroxene is predominantly enstatite (En85–100) with different mean values for crystals in and out of chondrules (En80.4 and En96.7, respectively). POP chondrules have high-Ca pyroxenes (En62.43Wo36.58Fs0.90). Kamacite (Ni = 4–5.00, mean value 4.61 [both wt%]; Co = 0.1–1.00, mean value 0.16 [both wt%]). Oxygen isotope: (I. Franchi and R. Greenwood, OU) δ17O = -6.042, δ18O = -2.306, ∆17O = -4.843 (all ‰). Classification: Carbonaceous chondrite (CO3); S2, minimal weathering. Specimens: All the fragments, two polished thin sections, and the main mass of 30 g are on deposit at the MSP (inventory number MSP 2283). | ||||||||||||||||||||||
| Data from: MB90 Table 1 Line 3: |
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| Plots: | O isotopes: | ||||||||||||||||||||||
| Institutions and collections |
MSP: Museo di Scienze Planetarie, Via Galcianese 20/H, 59100 Prato, Italy, Italy; Website (institutional address; updated 22 Oct 2022) OU: Planetary and Space Sciences Department of Physical Sciences The Open University Walton Hall Milton Keynes MK7 6AA United Kingdom, United Kingdom (institutional address; updated 8 Dec 2011) |
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| References: | Published in Meteoritical Bulletin, no. 90, MAPS 41, 1383-1418 (2006)
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Geography:
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Statistics: This is 1 of 426 approved meteorites from Tamanghasset, Algeria (plus 2 unapproved names) (plus 2 impact craters) This is 1 of 1315 approved meteorites from Algeria (plus 30 unapproved names) (plus 4 impact craters) | ||||||||||||||||||||||
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