High crustal diversity preserved in the lunar meteorite Mount DeWitt 12007 (Victoria Land, Antarctica)

The meteorite Mount DeWitt (DEW) 12007 is a polymict regolith breccia mainly consisting of glassy impact-melt breccia particles, gabbroic clasts, feldspathic clasts, impact and volcanic glass beads, basaltic clasts and mingled breccia clasts embedded in a matrix dominated by finegrained crystals; vesicular glassy veins and rare agglutinates are also present. Main minerals are plagioclase (typically An>85) and clinopyroxene (pigeonites and augites, sometimes interspersed). The presence of tranquillityite, coupled with the petrophysical data, the O-isotope data (D17O = -0.075) and the FeOtot/MnO ratios in olivine (91), pyroxene (65) and bulk rock (77) indicate a lunar origin for DEW 12007. Impactites consist of Al-rich impact melt splashes and plagioclase-rich meta-melt clasts. The volcanic products belong to the Very Low Titanium (VLT) or Low Titanium (LT) suites; an unusual subophitic fragment could be cryptomare-related. Gabbroic clasts could represent part of a shallow intrusion within a volcanic complex with prevailing VLT affinity. DEW 12007 has a mingled bulk composition with relatively high incompatible element abundances and shows a high crustal diversity, comprising clasts from the Moon's major terranes and rare lithologies. First order petrographic and chemical features suggest that DEW 12007 could be launch-paired with other meteorites including Y 793274/981031, QUE 94281, EET 87521/96008, and NWA 4884.