Anand, Mahesh; Taylor, Lawrence A.; Neal, Clive R.; Snyder, Gregory A.; Patchen, Allan; Sano, Yuji and Terada, Kentaro
Petrogenesis of lunar meteorite EET 96008.
Geochimica et Cosmochimica Acta, 67(18) pp. 3499–3518.
Lunar meteorite EET 96008 is a fragmental breccia that predominantly consists of basaltic mineral
clasts (0.5–2 mm), along with minor lithic fragments and breccia clasts. The matrix consists mainly of smaller
mineral fragments (0.5 mm), bound by glassy cement, the majority of which are pyroxene and plagioclase.
The pyroxene possesses extensive exsolution lamellae. These lamellae, up to 1 m in width, are atypical for
mare-basalts. One of the distinguishing textures of EET 96008 is the presence of small pockets (400 500
m) of mesostasis areas consisting of coarse (20 m) intergrowths of ferroaugite, fayalite and Si-rich glass.
Laths of ilmenite, armalcolite, apatite and whitlockite are also distributed in these areas. Ilmenite grains are
abundant and dispersed throughout the thin sections. Chromite and ulvo¨spinel are present but in minor
abundance. Troilite, generally rare in this rock, occurs as several grains in one pyroxene crystal. FeNi metal
is conspicuously absent from this meteorite.
The molar Fe/Mn ratio in olivines and pyroxenes and the age of the meteorite are evidence for a lunar
origin. The mineralogy of EET 96008 shows close affinity to a mare-basalt source, albeit with possible minor
highland/non-mare components. The bulk-rock, major-, trace- and rare-earth-element (REE) contents are
similar to that of very low-titanium (VLT) basalts, which have experienced extreme fractional crystallization
to the point of silicate liquid immiscibility. Mineralogical and textural features of this sample suggest that at
least some of the breccia components were derived from a slow-cooled magma. The mineralogy and petrology
of EET 96008 is strikingly similar to the lunar meteorite EET 87521, and we support the conclusion that EET
96008 and EET 87521 should be paired.
Isochron ages of 3530 270 Ma for apatite and 3519 100 Ma for whitlockite of this rock are consistent
with derivation from a mare-basalt precursor. These ages are within error of the low-Ti basalts, dated from the
Apollo 12 and 15 sites. The whole-rock, platinum-group-element (PGE) contents of EET 96008 overlap with
pristine low-Ti mare basalts, suggesting the presence of only a minimal extraterrestrial
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