Newsletter |
37,2 |
Location |
Miller Range |
Field Number |
22847 |
Dimensions (cm) |
3.0 x 2.5 x 2.0 |
Weight (g) |
30.83 |
Original Classification |
CO3 Chondrite |
Updated Classification |
CO3.15 Chondrite |
Pairing |
MIL 11069;
MIL 11154;
MIL 11157;
MIL 11178;
MIL 11187;
MIL 11237;
MIL 11252;
MIL 11261;
|
Fayalite (mol%): 25-55;Ferrosilite (mol%): 0-7 |
B |
A |
The exteriors of these CO3’s have brown/black fusion crust, some fractured with evaporites and rusty areas. The interiors range from rusty brown to black matrices with tiny white specks, some have rusty inclusions/chondrules. The textures range from fine to coarse grained. |
These sections consist of abundant, small (up to 1 mm) chondrules, chondrule fragments and mineral grains in a dark matrix. Metals and sulfides occur both within and rimming the chondrules. Olivine ranges in composition from Fa0-64, with a continuous range of intermediate compositions. Pyroxenes range from Fs1-15Wo1-3. The matrix appears to consist largely of Fe-rich olivine. These meteorites are CO3 chondrites and are likely paired with the MIL 07099 pairing group. |
Based on Type II (FeO-rich) chondrule olivine Cr content, this sample has been reclassified to CO3.15 chondrite. Details are reported in Righter, K. et al. (2024) Pairing relations within CO3 chondrites recovered at the Dominion Range and Miller Range, Transantarctic mountains: Constraints from chondrule olivines, noble gas, and H, C, N bulk and isotopic compositions. Meteoritics and Planetary Science 59; https://doi.org/10.1111/maps.14146. |
MIL 11069 pairing group has decidedly lower Type II chondrule olivine Cr2O3 contents than the other large MIL group. Given the geographic location of these members and their olivine compositions, we add three additional samples to this group – MIL 11178, MIL 11187, and MIL 11261 – for a total of eight samples. MIL 11178, 11187 and 11261 had been part of the MIL 07099 pairing group. |