Sample Petrographic Description
Sample Number | GRA 98103 |
Newsletter | 23,1 |
Location | Graves Nunataks |
Field Number | 11517 |
Dimensions (cm) | 5.0 x 3.0 x 2.5 |
Weight (g) | 41.08 |
Original Classification | Eucrite (Brecciated) |
Pairing | GRA 98006; GRA 98026; GRA 98044; GRA 98054; GRA 98067; GRA 98088; GRA 98103; GRA 98131; |
Mineral Composition (%Fa & %Fs) | |
Ferrosilite (mol%): 65 | |
Weathering | |
C | |
Fracturing | |
B | |
Macroscopic Description - Kathleen McBride | |
These meteorites have shiny black fusion crusts with some small, dull patches where thinning has occurred due to weathering. Some of the meteorites have shallow “vugs” that reveal coarse-grained tan to gray crystalline material as well as finer grained material. Several rusty patches on the rocks’ exterior surface are visible. A few of the meteorites have greenish-gray elongated or radiating crystals with some areas of rusty discoloration. The matrix on most is gray in color with clast colors ranging from white to tan to black. Several of the clasts are rimmed with dark gray to black crystalline material. GRA 98044 (27g) has a fusion crust that is mostly dull covering about 40% of the surface area. The matrix is gray in color with numerous charcoal gray inclusions and small rust halos. These eucrites are very soft and friable. | |
Thin Section Description - Tim McCoy | |
These meteorites consist of coarse-grained (mm-sized grains) basaltic clasts, which contain orthopyroxene (Fs64Wo2), with lamellae of augite (Fs28Wo44), and plagioclase (An88Or0.5). Augite lamellae in GRA 98044 are 1-5 microns in width and a range of intermediate compositions was measured. Shock effects include undulatory extinction in pyroxene and plagioclase. The Fe/Mn ratio of the pyroxene is ~30. The meteorites are brecciated eucrites. They are paired with GRA 98006. They are all coarse-grained, shocked, brecciated eucrites of similar composition. |
Antarctic Meteorite Images for Sample GRA 98103 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample GRA 98103 | ||||
Thin Section Photo(s) : | ||||