Sample Petrographic Description
Sample Number | GRA 98050 |
Newsletter | 23,1 |
Location | Graves Nunataks |
Field Number | 11547 |
Dimensions (cm) | 7.5 x 6.5 x 3.5 |
Weight (g) | 337.40 |
Original Classification | H3.8 Chondrite |
Pairing | GRA 98023; GRA 98024; GRA 98050; GRA 98087; |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 4-20;Ferrosilite (mol%): 16 | |
Weathering | |
C | |
Fracturing | |
C | |
Macroscopic Description - Kathleen McBride | |
These meteorites have small patches of black fusion crust on a rough, rusty brown exterior. Areas without fusion crust are rusty brown with penetrating fractures. The interiors are fine-grained and rusty with large fractures and a high metal content. Some gray and weathered chondrules are visible. | |
Thin Section Description - Tim McCoy | |
A single description suffices for these meteorites. The sections exhibit numerous small, well-defined chondrules (up to 1.5 mm) in a black matrix of fine-grained silicates, metal and troilite. Weak shock effects are present. Polysynthetically twinned pyroxene is extremely abundant. The meteorites are highly weathered. Silicates are unequilibrated; olivines range from Fa3-33, with most grains Fa18, and pyroxenes from Fs4-16. The meteorites are H3 chondrites (estimated subtype 3.8). |
Antarctic Meteorite Images for Sample GRA 98050 | ||||
Thin Section Photo(s) : | ||||
References for Sample GRA98050 | |
Menzies, O. N., Bland, P. A., Berry, F. J., Cressey, G., 2005, A M”ssbauer spectroscopy and X-ray diffraction study of ordinary chondrites: Quantification of modal mineralogy and implications for redox conditions during metamorphism. Meteoritics & Planetary Science, 40, 1023-1042, http://dx.doi.org/10.1111/j.1945-5100.2005.tb00171.x. |