¹S. E. Roberts,¹M. C. McCanta,^1,2M. M. Jean,¹L. A. Taylor
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13406]
¹Department of Barth and Planetary Sciences, University of Tennessee, Knoxville, Tennessee 37996, USA
²Department of Geological Sciences, University of Alaska Anchorage, Anchorage, Alaska 99508, USA
Published by arrangement with John Wiley & Sons

Northwest Africa (NWA) 10986 is a new mingled lunar meteorite found in 2015 in Western Sahara. This impact melt breccia contains abundant impact melt glass and clasts as large as 0.75 mm. Clasts are predominantly plagioclase and pyroxene‐rich and represent both highland and basalt lithologies. Highland lithologies include troctolites, gabbronorites, anorthositic norites, and troctolitic anorthosites. Basalt lithologies include crystalline clasts with large zoned pyroxenes representing very low titanium to low titanium basalts. In situ geochemical analysis of minerals within clasts indicates that they represent ferroan anorthosite, Mg‐suite, and gabbronorite lithologies as defined by the Apollo sample collection. Clasts representing magnesian anorthosite, or “gap” lithologies, are prevalent in this meteorite. Whole rock and in situ impact glass measurements indicate low incompatible trace element concentrations. Basalt clasts also have low incompatible trace element concentrations and lack evolved KREEP mineralogy although pyroxferroite grains are present. The juxtaposition of evolved, basaltic clasts without KREEP signatures and highland lithologies suggests that these basaltic clasts may represent cryptomare. The lithologies found in NWA 10986 offer a unique and possibly a complete cross section view of the Moon sourced outside of the Procellarum KREEP Terrane.

¹Samuel Ebert,¹Markus Patzek,¹Sarah Lentfort,¹Addi Bischoff
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13407]
¹Institut fur Planetologie, Westfälische Wilhelms-Universität Münster,  Wilhelm-Klemm-Str.10, 48149 Münster, Germany
Published by arrangement with John Wiley & Sons

One approach to decipher the dynamics of material transport and planetary accretion in the early solar system is to investigate xenolithic fragments in meteorites. In this work, we examined an igneous fragment from the NWA 12651 meteorite—the first igneous fragment found in any CM chondrite—by analyzing its mineralogy, rare earth elements (REEs), and O‐isotopes. The study shows that the exsolution lamellae of the igneous fragment consist of Fe‐rich and Ca‐rich pyroxene. Thus, the fragment was part of a progressive crystallization in a closed system, such as in a depleted magma reservoir or mantle. In this environment, the pyroxene co‐crystallized with plagioclase, resulting in a negative Eu anomaly and enrichment of the heavy REEs compared to the light REEs. The O‐isotopes of the fragment are more ¹⁶O‐enriched than the mafic minerals in the matrix or in other bulk CM chondrites; therefore, the fragment was formed in a different region than the NWA 12651 parent body. The iron meteorites Tucson and Deep Springs, the pallasite Milton, and the CB chondrites have similar O‐isotopes as the igneous fragment. However, no direct connection can be drawn and it is questionable if the fragment shares a same parent body with one of these meteorites. The close formation region to the CB chondrites may suggest a formation of the fragment in the carbonaceous chondrite region. Thus, a wide transport through the nebula of the early solar system may not have been necessary to move the fragment to the CM chondrite formation region.

¹Davide Lenaz,²Vanni Lughi,³Diego Perugini,^3,4Maurizio Petrelli,⁵Gianluca Turco,⁶Birger Schmitz
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13400]
¹Department of Mathematics and Geosciences, University of Trieste, 34128 Trieste, Italy
²Department of Engineering and Architecture, University of Trieste, 34127 Trieste, Italy
³Department of Physics and Geology, University of Perugia,06123 Perugia, ltaly
⁴INFN, Sezione di Perugia, 06123 Perugia, Italy
⁵Department of Medical Sciences, University of Trieste,Piazza dell’Ospitale 1, 34125 Trieste, Italy
⁶Astrogeobiology Laboratory, Department of Physics, Lund University, 22100 Lund, Sweden
Published by arrangement with John Wiley & Sons

MgAl₂O₄ spinels from Allende and NWA 763 carbonaceous chondrites were studied by X‐ray single crystal diffraction, SEM, electron microprobe, LA‐ICP‐MS, and Raman spectroscopy. Those from Allende are almost pure, but, in one case, we found a strong FeO_tot zonation. Spinels from NWA 763 show Mg‐Fe²⁺ substitutions. Almost pure MgAl₂O₄ spinels from both meteorites underwent slow cooling and reached their intracrystalline closure temperature (T_c) in the range 460–520 °C. The NWA 763 spinel with higher FeO content shows a T_c of about 720 °C. X‐ray single crystal diffraction and Raman spectroscopy suggest a slow cooling and an ordered structure with trivalent cations in M site and divalent in T site. Among the trace elements, Ti and Co are enriched with respect to the terrestrial analogs, while Mn, Ni, and Sn show intermediate values between different terrestrial occurrences. Vanadium cannot be used as a tracer of extraterrestrial origin as for Cr‐spinels, because its content is similar in extraterrestrial and terrestrial spinels. In the zoned crystal from Allende, Co show a strong zonation similar to that of FeO.