Sample Petrographic Description
Sample Number | LAP 02239 |
Newsletter | 26,2 |
Location | LaPaz Ice Field |
Field Number | 15176 |
Dimensions (cm) | 4.25 x 3.5 x 3.0 |
Weight (g) | 39.27 |
Original Classification | CM2 Chondrite |
Pairing | LAP 02239; LAP 02333; |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 0-46;Ferrosilite (mol%): 3-9 | |
Weathering | |
B | |
Fracturing | |
A/B | |
Macroscopic Description - Kathleen McBride | |
65% of the exterior of 239 has rough pitted black fusion crust with polygonal fractures and a purple cast. The interior is a black matrix with < mm sized tan and gray chondrules. 95% of 333's exterior is covered with thick chocolate brown fusion crust with a purplish tinge and polygonal fractures. The interior is a black matrix with mm sized white chondrules and inclusions. Two 4-5 mm gray clasts are visible. | |
Thin Section Description (,4) - Tim McCoy, Linda Welzenbach | |
The meteorites are so similar that a single description suffices. The sections consist of abundant small chondrules (most less than 0.5 mm), mineral grains and CAIs set in a black matrix; rare metal and sulfide grains are present. Olivine compositions are Fa0-55, with a majority Fa0-2, orthopyroxene is Fs1-9. The matrix consists dominantly of an Fe-rich serpentine. The meteorites are CM2 chondrites. |
Antarctic Meteorite Images for Sample LAP 02239 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample LAP 02239 | ||||
Thin Section Photo(s) : | ||||
References for Sample LAP02239 | |
Lee, M.R., Floyd, C., Martin, P.E., Zhao, X., Franchi, I.A., Jenkins, L., and Griffin, S., 2023, Extended time scales of carbonaceous chondrite aqueous alteration evidenced by a xenolith in La Paz Icefield 02239 (CM2). Meteoritics & Planetary Science., 58, 672-687, doi: 10.1111/maps.13978. | |
Alexander, C.M.O'D., Wynn, J.G., and Bowden, R., 2022, Sulfur abundances and isotopic compositions in bulk carbonaceous chondrites and insoluble organic material: Clues to elemental and isotopic fractions of volatile chalcophiles, Meteoritics & Planetary Science, 57, 334-351, doi:10.1111/maps.13746. | |
Lee, M.R., Cohen, B.E., Boyce, A.J., Hallis, LJ., and Daly, L., 2021, The pre-atmospheric hydrogen inventory of CM carbonaceous chondrites. Geochimica et Cosmochimica Acta, 309, 31-44, https://doi.org/10.1016/j.gca.2021.06.013. | |
Alexander, C. M. O'D., Bowden, R., Fogel, M. L., Howard, K. T., 2015, Carbonate abundances and isotopic compositions in chondrites. Meteoritics & Planetary Science, 50, 810-833, http://dx.doi.org/10.1111/maps.12410. | |
Alexander, C.O'D. M. O, Bowden,. R., Fogel, M. L., Howard, K. T., Herd, C. D. K., Nittler, L. R., 2012, The provenances of asteroids, and their contributions to the volatile inventories of the terrestrial planets. Science, 337(6095), 2012, 721-723. |