The lunar dunite clast, D1, from meteorite NWA 11421 represents the first sample that can be reliably traced to the lunar mantle and promises to provide new insights into the Moon’s interior structure and chemistry. We conducted electron backscatter diffraction (EBSD) analysis of the mantle clast to characterize olivine microstructures and to quantify its shock and thermal histories. The EBSD data indicate that D1 experienced a high-pressure, low-temperature shock event. Grain orientation spread (GOS) indicates a weighted shock stage (WSS) of 4.1 ± 1.3, corresponding to shock pressures between 15 and 20 GPa. Crystal rotation axis orientations associated with low-angle (2–10°) misorientations demonstrate preferential activation of C-type slip systems, consistent with relatively low shock temperatures of 723 ± 99 °C. Noticeably, this shock temperature estimate is below the sample’s equilibrium temperature of 980 ± 20 °C determined by Ca-in-pyroxene thermobarometry. This temperature contrast suggests that the thermal state achieved during shock was conducive to preserving the primary trace element signature of the mantle. The olivine within D1 displays a weak B-type crystallographic preferred orientation with a low M-index consistent with shock deformation when compared to various terrestrial mantle xenoliths. Combined with the sample’s depth of origin, these characteristics suggest D1 might have been launched from the Imbrium or Serenitatis basins and may provide the first direct chemical constraints on nearside lunar mantle.
