Newsletter |
20,2 |
Location |
Grosvenor Mountains |
Field Number |
10929 |
Dimensions (cm) |
11.5 x 7.0 x 8.0 |
Weight (g) |
840.40 |
Original Classification |
L3.5 Chondrite |
Updated Classification |
L3.2 Chondrite |
Pairing |
GRO 95502;
GRO 95504;
GRO 95505;
GRO 95512;
GRO 95539;
GRO 95542;
GRO 95544;
GRO 95545;
GRO 95546;
GRO 95550;
|
Fayalite (mol%): 3-21;Ferrosilite (mol%): 8-28 |
B |
A |
All three of these ordinary chondrites have a brown/black fusion crusted exterior with chondrules/clasts visible. The interiors reveal a brownish black matrix with abundant chondrules that range in size from mm to 1 cm. All three have minor metal and some rusty areas. |
The sections are so similar that a single description will suffice; the meteorites are probably paired. The sections show numerous chondrules and chondrule fragments, up to 3.2 mm across, in a black matrix containing small amounts of nickel-iron and troilite. The chondrules are mainly granular and porphyritic olivine and olivine-pyroxene, with a few radiating and cryptocrystalline pyroxene. Microprobe analyses show olivine and pyroxene of variable compositions: olivine, Fa2-24, mean Fa14; pyroxene, Fs1-28. The meteorites are classified as L3 chondrites (estimated L3.5). They are very similar to GRO95505, 95544, 95545, and the possibility of pairing should be considered. |
Reclassified as an L3.2 Chondrite based on Cr contents of Type II chondrule olivine. Pairing groups adjusted based on olivine composition and recovery location. Righter, K., Schutt, J., Lunning, N., Harvey, R., & Karner, J. (2021a) Identification and pairing reassessment of unequilibrated ordinary chondrites from four Antarctic dense collection areas. Meteoritics & Planetary Science 56, 1556-1578. |
Righter et al. (2021) propose that GRO 95502, GRO 95504, GRO 95505, GRO 95512, GRO 95539, GRO 95542, GRO 95544, GRO 95545, GRO 95546, and GRO 95550 are all paired and type L3.2. |