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from
The
Meteoritical Bulletin, No. 94, September 2008. Meteoritics & Planetary Science
43,
1551–1588 (2008)
Northwest
Africa 5207
Morocco
Find: 2007
Mass: 101 g
Achondrite
(lunar feldspathic breccia)
History
and physical characteristics: A 101 g stone was purchased
in Rissani, Morocco in 2007 by A. Aaronson. The
exterior is dark in color.
Petrography (T.
Bunch and J. Wittke, NAU): The fragmental matrix
contains a wide variety of lithic, glassy, and shocked components that
mainly include plagioclase-olivine orthocumulates, recrystallized noritic
and troctolitic anorthosites, anorthosites, gabbros and course to
fine-grained basalts, microbreccias, shock-melted lithologies, symplectites
(from pyroxferroite decomposition), very sparse Apollo-like “green glasses”
(A), and irregular-shaped light to dark green glasses (B), some of which
are vesicular and contain tiny metal-sulfide spherules. The interior
weathering grade is very low.
Mineral/phase
chemistry:
Orthocumulate olivine, Fa26.5 (FeO/MnO = 96) and plagioclase, An99.3.
Coarse-grained basalt olivine is Fa30; Ca-pyroxene core, Fs45.1Wo30.4
and rim, Fs62.7Wo16.8; plagioclase, An87.7.
Fine-grained basalt olivine is Fa56.9 (FeO/MnO = 93);
Ca-pyroxene, Fs28.5Wo34.7; plagioclase, An91.2.
Green glasses (B) in wt %: SiO2 = 43.8; Al2O3
= 18.7; Cr2O3 = 0.50; TiO2 = 0.78; FeO =
12.5; MgO = 7.0; CaO = 15.2; K2O = 0.33 and Na2O =
0.58 (N = 17).
Bulk
chemistry
(R. Korotev, WUSL):
Na2O = 0.484 wt %; Sc = 15.52 ppm; Cr = 1065 ppm; FeO = 7.56 wt
%; Co = 26.7 ppm; Ni = 233 ppm; Th = 1.26 ppm and Ba = 123 ppm.
Classification:
Achondrite (lunar, feldspathic breccia).
Type
specimen: A total of 20 g is
on deposit at NAU.
The main mass holder is anonymous.
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