Sample Petrographic Description
Sample Number | MIL 090075 |
Newsletter | 33,2 |
Location | Miller Range |
Field Number | 20886 |
Dimensions (cm) | 6.5 x 5.5 x 4.0 |
Weight (g) | 143.52 |
Original Classification | Lunar-Anorth. Breccia |
Updated Classification | Lunar Anorthositic Regolith Breccia |
Pairing | MIL 090070; MIL 090034; MIL 090075; |
Mineral Composition (%Fa & %Fs) | |
Fayalite (mol%): 39;Ferrosilite (mol%): 9-43 | |
Weathering | |
Ae | |
Fracturing | |
B | |
Macroscopic Description - Roger Harrington | |
40% of the exterior of this sample is covered with a shiny olive green fusion crust. The remaining 60% is broken surface which consists of dark green to gray fine-grained matrix with elongate and equant pale green clasts that range in size from 2-7 mm. White clasts ranging in size from 1-2 mm are present within the pale green clasts. Some evaporite material is encrusted on the broken surface. The interior of this sample consists of a dark green, fine-grained matrix with 3-5 mm gray clasts throughout. | |
Thin Section Description (,2) - Cari Corrigan, Tim McCoy, Linda Welzenbach | |
The sections consist of an extremely fine-grained matrix with isolated mineral grains and fine- to coarse-grained basaltic clasts in all size ranges up to 2 mm. Microprobe analyses reveal olivine of Fa37-42, pyroxene in a wide range of compositions from pigeonite Fs20-43Wo6-19 to augite of Fs9Wo43 with intermediate and more FeO-rich compositions, and plagioclase of An89-98. The Fe/Mn ratio of the pyroxene averages ~59. These meteorites were found 10 cm apart in the field and are similar enough that only one description is necessary. They are likely paired. The meteorite(s) is/are a basalt-bearing anorthositic regolith breccia. | |
Reclassification Notes (AMN 47,1) | |
Paired these three based on CRE ages and composition, and revised the name based on glassy spherules reported in matrix (i.e., regolithic) (Calzada-Diaz et al., 2017; Nishiizumi and Caffee, 2013; Zeigler and Korotev, 2016). Calzada‐Diaz, A., Joy, K. H., Crawford, I. A., & Strekopytov, S. (2017) The petrology, geochemistry, and age of lunar regolith breccias Miller Range 090036 and 090070: Insights into the crustal history of the Moon. Meteoritics & Planetary Science, 52(1), 3-23. Nishiizumi, K., & Caffee, M. W. (2013) Relationships among six lunar meteorites from Miller Range, Antarctica based on cosmogenic radionuclides. In 44th Annual Lunar and Planetary Science Conference (No. 1719, p. 2715). Zeigler, R. A., & Korotev, R. L. (2016) Petrography and Geochemistry of Lunar Meteorite Miller Range 13317. In 47th Annual Lunar and Planetary Science Conference (No. 1903, p. 2554). |
Antarctic Meteorite Images for Sample MIL 090075 | ||||
Lab Photo(s) : | ||||
Antarctic Meteorite Images for Sample MIL 090075 | ||||
Thin Section Photo(s) : | ||||
References for Sample MIL090075 | |
McIntosh, E. C., Day, J. M. D., Lui, Y., Jiskoot, C., 2020, Examining the compositions of impactors striking the Moon using Apollo impact melt coats and anorthositic regolith breccia meteorites. Geochimica et Cosmochimica Acta, 274, 192-210, doi: 10.1016/j.gca.2020.01.051. | |
Martin, D. J., Pernet-Fisher, J. F., Joy, K. H., Wogelius, R. A., Morlok, A., & Hiesinger, H. , 2017, Investigating the shock histories of lunar meteorites Miller Range 090034, 090070, and 090075 using petrography, geochemistry, and micro?FTIR spectroscopy. . Meteoritics & Planetary Science, 52, 1103-1124, doi: 10.1111/maps.12860. | |
Calzada-Diaz, A., Joy, K. H., Crawford, I. A., & Strekopytov, S. , 2017, The petrology, geochemistry, and age of lunar regolith breccias Miller Range 090036 and 090070: Insights into the crustal history of the Moon. . Meteoritics & Planetary Science, 52, 3-23, doi: 10.1111/maps.12737. | |
Korotev, R.L., and Zeigler, R.A., 2015, ANSMET Meteorites from the Moon. In Righter, K., Corrigan, C.M., McCoy, T.J., and Harvey, R.P. Meteorites: A Pictorial Guide to the Collection, First Edition, AGU Wiley, pp. 101-130. |