The early geological history of the Moon inferred from ancient lunar meteorite Miller Range 13317

<jats:title>Abstract</jats:title><jats:p>Miller Range (<jats:styled-content style="fixed-case">MIL</jats:styled-content>) 13317 is a heterogeneous basalt‐bearing lunar regolith breccia that provides insights into the early magmatic history of the Moon. <jats:styled-content style="fixed-case">MIL</jats:styled-content> 13317 is formed from a mixture of material with clasts having an affinity to Apollo ferroan anorthosites and basaltic volcanic rocks. Noble gas data indicate that <jats:styled-content style="fixed-case">MIL</jats:styled-content> 13317 was consolidated into a breccia between 2610 ± 780 Ma and 1570 ± 470 Ma where it experienced a complex near‐surface irradiation history for ~835 ± 84 Myr, at an average depth of ~30 cm. The fusion crust has an intermediate composition (Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> 15.9 wt%; FeO 12.3 wt%) with an added incompatible trace element (Th 5.4 ppm) chemical component. Taking the fusion crust to be indicative of the bulk sample composition, this implies that <jats:styled-content style="fixed-case">MIL</jats:styled-content> 13317 originated from a regolith that is associated with a mare‐highland boundary that is <jats:styled-content style="fixed-case">KREEP</jats:styled-content>‐rich (i.e., K, rare earth elements, and P). A comparison of bulk chemical data from <jats:styled-content style="fixed-case">MIL</jats:styled-content> 13317 with remote sensing data from the Lunar Prospector orbiter suggests that <jats:styled-content style="fixed-case">MIL</jats:styled-content> 13317 likely originated from the northwest region of Oceanus Procellarum, east of Mare Nubium, or at the eastern edge of Mare Frigoris. All these potential source areas are on the near side of the Moon, indicating a close association with the Procellarum <jats:styled-content style="fixed-case">KREEP</jats:styled-content> Terrane. Basalt clasts in <jats:styled-content style="fixed-case">MIL</jats:styled-content> 13317 are from a very low‐Ti to low‐Ti (between 0.14 and 0.32 wt%) source region. The similar mineral fractionation trends of the different basalt clasts in the sample suggest they are comagmatic in origin. Zircon‐bearing phases and Ca‐phosphate grains in basalt clasts and matrix grains yield <jats:sup>207</jats:sup>Pb/<jats:sup>206</jats:sup>Pb ages between 4344 ± 4 and 4333 ± 5 Ma. These ancient <jats:sup>207</jats:sup>Pb/<jats:sup>206</jats:sup>Pb ages indicate that the meteorite has sampled a range of Pre‐Nectarian volcanic rocks that are poorly represented in the Apollo, Luna, and lunar meteorite collections. As such, <jats:styled-content style="fixed-case">MIL</jats:styled-content> 13317 adds to the growing evidence that basaltic volcanic activity on the Moon started as early as ~4340 Ma, before the main period of lunar mare basalt volcanism at ~3850 Ma.</jats:p>