Sample Petrographic Description
Sample Number | LAP 02216 |
Newsletter | 26,2 |
Location | LaPaz Ice Field |
Field Number | 15523 |
Dimensions (cm) | 9.0 x 7.0 x 4.25 |
Weight (g) | 612.60 |
Original Classification | Diogenite |
Pairing | LAP 91900; LAP 02216; LAP 031000; LAP 031309; LAP 03781; LAP 03796; LAP 04836; LAP 04837; LAP 04839; |
Mineral Composition (%Fa & %Fs) | |
Ferrosilite (mol%): 23 | |
Weathering | |
B | |
Fracturing | |
A/B | |
Macroscopic Description - Kathleen McBride | |
50% of the exterior has a chocolate brown fusion crust. The fusion crust is in patches and has a dull luster with polygonal fractures. The exposed interior has a greenish gray color and shows numerous inclusions. The interior is composed of a concrete gray matrix containing numerous olivine clasts of various sizes (mm to cm). The clasts range in color from a deep gray-green to light areas. There are a few black minerals with a rusty stain around them. The rock has a 0.5 to 0.75 cm weathering rind, yellow to rust in color. The clasts are easily plucked. There are many casts where olivine grains had been. | |
Thin Section Description (,6) - Tim McCoy, Linda Welzenbach | |
The section shows a groundmass of coarse (up to 1.5 mm) comminuted pyroxene, with minor SiO2. Orthopyroxene has a composition of Fs23Wo2 and an Fe/Mn ratio of ~28. The meteorite is a diogenite and is compositionally similar to LAP 91900, with which it may be paired. |
Antarctic Meteorite Images for Sample LAP 02216 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample LAP 02216 | ||||
Thin Section Photo(s) : | ||||
References for Sample LAP02216 | |
Dyar, M.D., Wallace, S.M., Burbine, T.H., and Sheldon, D.R., 2023, A machine learning classification of meteorite spectra applied to understanding asteroids. Icarus, 406, 115718, https://doi.org/10.1016/j.icarus.2023.115718. | |
Mittlefehldt, D. W., 2015, Asteroid (4) Vesta: I. The howardite-eucrite-diogenite (HED) clan of meteorites. Chemie der Erde - Geochemistry, 75 Issue 2, Jun-15, 155-183, ISSN 0009-2819, http://dx.doi.org/10.1016/j.chemer.2014.08.002. | |
Beck, A. W., Mcsween Jr., H. Y., 2010, Diogenites as polymict breccias composed of orthopyroxenite and harzburgite. Meteoritics & Planetary Science, 45, 850-872, http://dx.doi.org/10.1111/j.1945-5100.2010.01061.x. | |
Barrat, J. A., Yamaguchi, A., Greenwood, R. C., Benoit, M., Cotten, J., Bohn, M., Franchi, I. A., 2008, Geochemistry of diogenites: Still more diversity in their parental melts. Meteoritics & Planetary Science, 43, 1759-1775, http://dx.doi.org/10.1111/j.1945-5100.2008.tb00641.x. | |
Welten, K.C., Hillegonds, D.J., Masarik, J., and Nishiizumi, K., 2007, Cosmogenic 41Ca in diogenites: Production rates, pre-atmospheric size and terrestrial ages, Nuclear Instruments and Methods in Physics Research B, 259, 653-662, doi: 10.1016/j.nimb.2007.01.204. | |
RELAB, , Reflectance Experiment Lab , catalogue of samples. |