Petrologic Comparisons of Lunar Mare Basalt Meteorites Dh-287A and NWA

Introduction: It is intriguing that the majority of lunar meteorites (~30) have been discovered in the hot deserts of Middle-East and North Africa. In contrast, of 10s of thousands of meteorite finds from Antarctica over 30 years, only a handful (~5) are lunar. This bias towards the lunar meteorite recovery from the hot deserts may be due to the preferential fall of lunar meteorites in these regions. This may be a direct result of the dynamics of the Earth-Moon system and preferential orbits of the lunar meteorites near the plane of the E-M system. Alternatively, it could be related to limited number of falls comprising a variety of lunar lithologies (e.g., mare-basalts, highlands breccias). Recently, two new mare basalt meteorites have been recovered from the hot deserts, and it is the aim of this study to compare their petrogenetic histories in an assessment of possible source-area pairing. Dhofar 287 (Dh-287) and North West Africa 032 (NWA 032) were recovered from the desert regions of Oman and the Sahara, NW Africa, resp. Dh287 consists mainly (> 95%) of a large mare basalt clast (Dh-287A) with a small portion of a breccia (Dh287B) attached on one side. To date, these rocks represent two out of only 5 mare basalt meteorites in the entire lunar collection, having fallen only a few thousand kilometers apart. Although these two basalts have been studied previously [1,2], no direct comparisons have been made. Therefore, they form an important group of samples that provide clues to the magmatic history of the Moon. Both meteorites are akin to low-Ti basalts of A-12 and 15, but have distinct petrogenesis.