Sample Petrographic Description
Sample Number | MIL 091004 |
Newsletter | 35,2 |
Location | Miller Range |
Field Number | 18819 |
Dimensions (cm) | 3.0 x 2.3 x 2.0 |
Weight (g) | 32.53 |
Original Classification | Lodranite |
Updated Classification | Ureilite |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 12;Ferrosilite (mol%): 10 | |
Weathering | |
B/C | |
Fracturing | |
A | |
Macroscopic Description - Cecilia Satterwhite | |
The exterior has 95% black/brown fusion crust with rusty areas. The interior is a rusty brown with metal and has a crystalline texture. | |
Thin Section Description (,2) - Cari Corrigan, Tim McCoy, Linda Welzenbach | |
The meteorite is an equigranular aggregate (1 mm grain size) of olivine and pyroxene and very rare plagioclase in a metal-rich matrix. Stringers of metal and rare sulfide occupy grain boundaries between mafic silicates. Olivine (Fa12), low-Ca pyroxene (Fs10Wo5), high-Ca pyroxene (Fs6Wo37). The meteorite is a lodranite. | |
Reclassification Notes (AMN 45,2) | |
Petrologic geochemical, and isotopic data acquired since the original classification of MIL 091004 as a lodranite in AMN 35, 2, has necessitated the reclassification of this sample as a ureilite (Day et al., 2017). Pyroxene and olivine compositions from MIL 091004 fall within the compositional space defined by ureilites. In addition, oxygen isotopic composition clearly shows that MIL 091004 is a ureilite, not a lodranite. It is thus well justified to re-classify this sample as a ureilite. |
Antarctic Meteorite Images for Sample MIL 091004 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample MIL 091004 | ||||
Thin Section Photo(s) : | ||||
References for Sample MIL091004 | |
Day, J. M., Corder, C. A., Cartigny, P., Steele, A., Assayag, N., Rumble, D., & Taylor, L. A. , 2017, A carbon-rich region in Miller Range 091004 and implications for ureilite petrogenesis. Geochimica et Cosmochimica Acta, 198, 379-395, http://dx.doi.org/10.1016/j.gca.2016.11.026. | |
RELAB, , Reflectance Experiment Lab , catalogue of samples. |