Meteoritical Bulletin: Entry for Dominion Range 10344

Writeup from AMN 37(1):

Sample Number	DOM 10344
Newsletter	37,1
Location	Dominion Range
Field Number	21109
Dimensions	4.5 x 3.3 x 2.8
Weight	68.36
Original Classification	CR2 chondrite
Pairing	DOM 10077, DOM 10344, DOM 10467
Mineral Composition (%Fa & %Fs)
Fayalite (mol%): 3-33; Ferrosilite (mol%): 3-13
Macroscopic Description - Kathleen McBride and Cecilia Satterwhite
These carbonaceous chondrites have brown/black fusion crust with oxidation haloes and rusty areas. The dark gray/black interior has abundant chondrules/inclusions of various sizes and color. Some metal is present.
Thin Section Description (,2) - Linda Welzenbach, Pamela Salyer and Tim McCoy
These sections exhibit small (100-300 microns), well-defined, metal-rich grains, and up to 2mm chondrules and a few CAIs in a dark matrix of FeO-rich phyllosilicate. Polysynthetically twinned pyroxene is abundant. Silicates are unequilibrated; olivines range from Fa_2-33, and pyroxenes from Fs_1-23Wo_0-2. These meteorites are CR2 chondrites and are similar enough to be initially paired.

Antarctic Meteorite Images for Sample DOM 10344

Reclassification Notes (AMN 37,2)

Petrographic studies and INAA data provided by Alan Rubin and John Wasson (UCLA) indicate that DOM 10344 is an LL3 chondrite, probably LL3.4.

DOM 10344 has higher sulfide contents than a typical CR2. It has Radial Pyroxene and cryptocrystalline chondrules, which are very rare in CRs, and it has few igneous rims, which are common in CRs. UCLA probe data show Fa_10.5±7.5 (n=16) and Fs_10.9±8.7 (n=6). The PMD of Fa is 55, corresponding to subtype <3.4. It has rare clear, colorless, isotropic glass, approximately the same as for type 3.4-3.5 OC. Its Cr₂O₃ in ferroan olivine is 0.07±0.07 wt%, corresponding to type >3.2. So, it is probably best classified as an LL3.4.

In addition, INAA data show 472 µg/g Co and 426 ng/g Ir in DOM 10344. This compares with a mean of 490 and 360 for LL chondrites (from Wasson and Kallemeyn, 1988) and 667 and 642 for CR chondrites from Kallemeyn et al. (1994). Additionally, DOM 10344 contains 129 ng/g Au which does not distinguish it from a CR, but is nonetheless consistent with LL.