Carbonaceous
Name
*click on the Name for more information
Structure Class
Carbonaceous chondrites
Chemical Class
C3.00-ung
Country
Year found
2018
Mass
779 g
[Museum Collection]
(1) 3.7g (2) 1.6g (3) 1.6g (4) 1.2g
History: Found close to Houza village by Elho Sbiti on June 10, 2018. Bought from Mohamed Elguirad in Guelmim in June and October 2018. More samples bought from Mohamed Elguirah, Habib-Naji Naji and Youssef Ait El Caid in January 2019. Some material bought by Nourddine Azelmat. Physical characteristics: Fragments and crusted stones, including a 158 g full stone. Cut surface reveals a dark porous interior with chondrules. Petrography: (J. Gattacceca, CEREGE) Chondrite with well-defined chondrules (average apparent diameter 480±300 μm, n=29) set in an abundant fine-grained iron-rich matrix (74 vol%, by point counting, n=371). Opaques are troilite, magnetite, rare metal (as inclusion in silicates and in the matrix). XRD over a ~1 cm2 area on a polished section (D. Borschnek, CEREGE) does not reveal the presence of hydrous phases (serpentine, tochilinite) typically observed in type 2 chondrites using the same experimental setup. In contrast to type 2 chondrites, IR transmission spectroscopy (L. Bonal, IPAG) on matrix grains only reveal a faint water and Si-O-band (attributable to phyllosilicates), reflecting a very low extent of aqueous alteration. Based on the structural order of the polyaromatic matter assessed by Raman spectroscopy (L. Bonal, IPAG), this meteorite appears to be less heated than the least heated type 3 ordinary chondrite, Semarkona. Geochemistry: Olivine Fa37.6±16.7, range Fa1.2-46.5 (n=16), Cr2O3 in ferroan olivine 0.39±0.12 wt% (n=11). Low-Ca pyroxene Fs3.1±3.0Wo0.8±0.3 (n=4). Defocussed (10 μm) microprobe totals in the matrix 90.9±1.2% (n=11). Oxygen isotopic composition (J. Gattacceca, C. Sonzogni, CEREGE) from analysis of one acid-washed 1.5 mg aliquot of a powdered 38 mg bulk sample is δ17O=0.42‰, δ18O=8.23‰ , Δ17O=-3.88‰ (linearized, slope 0.5247, analytical uncertainties 0.08‰, 0.12‰, 0.03‰ respectively). Classification: Carbonaceous chondrite (C3.00-ungrouped). This meteorite is distinct from CM2 chondrites for its larger chondrule size and only incipient aqueous alteration. Type 3.00 is based on the non-detection of phyllosilicates by XRD and microprobe total in the matrix higher than usually measured in type 2 chondrites (see e.g., Ebert et al. 2019, MAPS doi:10.1111/maps.13212), and Raman spectroscopy. Possibly paired with NWA 12957 and NWA 11750 despite having distinct oxygen isotopic composition. Specimens: Type specimen at CEREGE. Main mass with Jean Redelsperger and Nourddine Azelmat.
Name
*click on the Name for more information
Structure Class
Carbonaceous chondrites
Chemical Class
C2-ung
Country
Year found
2000
Mass
10 kg
[Museum Collection]
(1) 1.28g (2) 3g
This is 1 of 25 approved meteorites classified as C2-ung. Published in Meteoritical Bulletin, no. 84, MAPS 35, A199-A225 (2000) Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
Name
*click on the Name for more information
Structure Class
Carbonaceous chondrites
Chemical Class
C2-ung
Country
Year found
2019
Mass
1027 g
[Museum Collection]
(1) 26g
History: The meteorite was purchased from a meteorite dealer in Morocco. Physical characteristics: Five black individuals partly covered with fusion crust. Petrography: The meteorite a brecciated matrix-dominated carbonaceous chondrite with chondrules (mean diameter about 300 μm), mineral fragments, and few CAIs. Most of the components are surrounded by fine-grained dust rims. The matrix is highly porous and composed of Ca-carbonates, phyllosilicates with fibrous and flaky appearance, and Fe-sulfides. Some FeNi metal grains are present mostly as inclusions in forsteritic olivine. Geochemistry: Mean values of defocused matrix analyses (beam diameter 10 µm; all wt%; N=25): SiO2: 24.1, TiO2: 0.03, Na2O: 0.46, Cr2O3: 0.29, MgO: 13.9, MnO: 0.16, FeO: 31.2, Al2O3: 2.50, NiO: 2.10, P2O5: 0.34, S: 4.6, Total: 79.69; Oxygen isotopes (K. Ziegler, UNM): 6 acid-washed fragments analyzed by laser fluorination gave: δ18O=-6.769, -2.952, -1.991, 1.322, -2.345, -3.978; δ17O=-10.566, -7.481, -6.795, -4.079, -6.747, -8.036; Δ17O= -6.992, -5.922, -5.744, -4.777, -5.509, -5.936 (all per mil) Classification: C2 due to petrography and presence of phyllosilicates and carbonates. Ungrouped according to oxygen isotopic composition which is incompatible with CM.