Sample Petrographic Description
Sample Number | MIL 090221 |
Newsletter | 34,2 |
Location | Miller Range |
Field Number | 20801 |
Dimensions (cm) | 4.0 x 3.0 x 1.5 |
Weight (g) | 33.98 |
Original Classification | Diogenite |
Pairing | MIL 07003; MIL 07613; MIL 090105; MIL 090106; MIL 090107; MIL 090112; MIL 090159; MIL 090220; MIL 090221; MIL 090291; MIL 11099; MIL 11197; MIL 11198; MIL 11199; MIL 11201; MIL 11202; MIL 11204; MIL 11205; |
Mineral Composition (%Fa & %Fs) | |
Ferrosilite (mol%): 32-37 | |
Weathering | |
B | |
Fracturing | |
A/B | |
Macroscopic Description - Kathleen McBride | |
These achondrites are covered with brown/black fusion crust (50-85%), shiny in areas and have some areas with polygonal fractures. The interior matrices are tan with small mm sized white, tan and black inclusions. 0221 has dendritic looking dark veins that surround some clasts. | |
Thin Section Description (,2) - Cari Corrigan, Linda Welzenbach, Andrew Beck, Nicole Lunning | |
These meteorites are similar enough that one description is sufficient. Thin sections of each show a groundmass of coarse (up to 1.5 mm) comminuted pyroxene, with minor plagioclase and SiO2. Orthopyroxene has a composition of Fs32-36Wo2-4, augites are Fs12-15Wo40-43 and plagioclase is An84-89Or0-1. The Fe/Mn ratio of the pyroxene is 26-30. These meteorites are diogenites. | |
Notes | |
MIL 07003, MIL 07613 (4 – 090105, 090106, 090107), MIL 090159 (3 – 090220, 090221), MIL 090112 (7 – 090291, 11099, 11201, 11202, 11204, 11205), MIL 11197, MIL 11198, and MIL 11199. Combination of these three diogenite pairing groups as well as four previously unpaired masses to form a new large 18 member pairing group of diogenites MIL 07003; based on terrestrial ages, compositions, find locations, and petrographic textures. Pairing updated in AMN 47,1. |
Antarctic Meteorite Images for Sample MIL 090221 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample MIL 090221 | ||||
Thin Section Photo(s) : | ||||