Petrography, mineralogy and geochemistry of the lunar basaltic meteorite NWA 14526

The NWA 14526 meteorite is a lunar basaltic meteorite that formed approximately 3 billion years ago. To further investigate its origin, in this paper, we systematically reported its petrographic, mineral chemical, and Sr-Nd isotopic characteristics. Detailed petrographic and mineralogical analyses reveal that it is an olivine-rich low-Ti basalt. Both olivine (Fo29-61) and pyroxene (En23-61Fs21-60Wo8-36) have significant compositional zones, indicating that they had experienced obvious crystallization differentiation process. Compared to the lunar basaltic meteorites and Chang’e-6 basalts with similar formation ages, the NWA 14526 meteorite and its pyroxenes have relatively low abundances of rare-earth element (REE), suggesting that there was a relatively low degree magmatic evolution and its composition is relatively similar to that of the primitive lunar mantle. Furthermore, it has depleted Sr-Nd isotopic characteristics, with its initial （87Sr/86Sr）i ratios ranging from 0.69953 to 0.70015 and εNd values ranging from +10.1 to +10.7, which are varied within the range of Sr-Nd isotopes of both Chang’e-5 and Chang’e-6 basalts, indicating that the NWA 14526 meteorite was derived from a highly depleted lunar mantle source. This study not only advances our understanding of the composition and evolution of the lunar mantle, but also further proves that the KREEP material rich in potassium, rare-earth elements and phosphorus is not a necessary component for the young volcanic activities on the Moon.