Lot Essay
The Dar al Gani 262 meteorite was found in the Sahara Desert of Libya on 23 March 1997. Lunar meteorites are very rare, the first having been found in the Antarctic in 1982. Since then, only eighteen separate rocks have been identified as being of lunar origin, some of which undoubtedly originated from the same blasted-off rock source.
The Dar al Gani 262 meteorite originally weighed 513g, and preliminary study on it was carried out by Bischoff and Weber who determined that the rock was of lunar origin, based on its texture, types of mineral, glass, and lithic clasts, mineral composition and bulk composition. This fragment has been further examined by Professors Larry A. Haskin, Randy L. Korotev and Bradley Jolliff, of the Department of Earth and Planetary Sciences, Washington University, St Louis, Missouri, USA. Examinations were made of mineral, matrix and fusion crust compositions. Comparison was also made with lunar meteorite QUE93069 which, it has been suggested, is from the same point of origin. The findings of Haskin, Korotev and Jolliff suggest no reason to argue against this hypothesis: " the highly feldspathic bulk composition and apparent paucity of mafic and KREEP-like components indicates that the DaG 262 and QUE93069 meteorites, like Yamato 791197, Yamato 82192/3, Yamato 86032, and MacAlpine Hills 88104/5 [8], derived from impacts into the Feldspathic Highlands Terrane [9]. The bulk compositions and the compositions of lithic and mineral clasts reflect precursor rock formations dominated by the ferroan-anorthositic suite (anorthosite - noritic anorthosite - anorthositic norite) and impactite lithologies derived largely from the ferroan igneous precursors. Glasses also have relatively low Mg' values. Although the fusion crust composition indicates a somewhat more magnesian bulk composition than the clast population we happened to analyze, it remains that magnesian mafic clast compositions are subordinate to ferroan ones. The paucity of magnesian-suite lithic clasts and impactites derived therefrom supports the hypothesis (e.g. [8], [9]) that rocks of the magnesian suite, as sampled by the Apollo missions, derive largely from the central nearside of the Moon, especially the region of the Procellarum KREEP Terrane and within the ejecta of basin impacts that struck near or within that terrane." (Jolliff et al. "Electron microphobe...", 1999). Further information can be found on the Internet at https://epsc.wustl.edu/admin/research/dag262.html
Full documentation of the research carried out byProfessors Haskin, Korotev and Jolliff is included with this Lot.
The Dar al Gani 262 meteorite originally weighed 513g, and preliminary study on it was carried out by Bischoff and Weber who determined that the rock was of lunar origin, based on its texture, types of mineral, glass, and lithic clasts, mineral composition and bulk composition. This fragment has been further examined by Professors Larry A. Haskin, Randy L. Korotev and Bradley Jolliff, of the Department of Earth and Planetary Sciences, Washington University, St Louis, Missouri, USA. Examinations were made of mineral, matrix and fusion crust compositions. Comparison was also made with lunar meteorite QUE93069 which, it has been suggested, is from the same point of origin. The findings of Haskin, Korotev and Jolliff suggest no reason to argue against this hypothesis: " the highly feldspathic bulk composition and apparent paucity of mafic and KREEP-like components indicates that the DaG 262 and QUE93069 meteorites, like Yamato 791197, Yamato 82192/3, Yamato 86032, and MacAlpine Hills 88104/5 [8], derived from impacts into the Feldspathic Highlands Terrane [9]. The bulk compositions and the compositions of lithic and mineral clasts reflect precursor rock formations dominated by the ferroan-anorthositic suite (anorthosite - noritic anorthosite - anorthositic norite) and impactite lithologies derived largely from the ferroan igneous precursors. Glasses also have relatively low Mg' values. Although the fusion crust composition indicates a somewhat more magnesian bulk composition than the clast population we happened to analyze, it remains that magnesian mafic clast compositions are subordinate to ferroan ones. The paucity of magnesian-suite lithic clasts and impactites derived therefrom supports the hypothesis (e.g. [8], [9]) that rocks of the magnesian suite, as sampled by the Apollo missions, derive largely from the central nearside of the Moon, especially the region of the Procellarum KREEP Terrane and within the ejecta of basin impacts that struck near or within that terrane." (Jolliff et al. "Electron microphobe...", 1999). Further information can be found on the Internet at https://epsc.wustl.edu/admin/research/dag262.html
Full documentation of the research carried out byProfessors Haskin, Korotev and Jolliff is included with this Lot.