LUN A - Anorthositic Highland Rocks

The members of this group are designated "LUN A" for their mineral compositions. They are anorthosites, consisting primarily of calcium-rich plagioclase with only minor pyroxene and olivine. Originally, they were coarse-grained, plutonic rocks, forming the ancient highlands that dominate both sides of the Moon. Over time, these rocks were thoroughly granulated, heavily brecciated, and partially melted by impacts, leading to the establishment of three subtypes of lunar anorthosites - regolith breccias, impact-melt breccias, and fragmental breccias.

Regolith breccias: The lunar surface is covered by a thick regolith layer, and consequently, most lunaites are polymict regolith breccias. These rocks consist of abundant white clasts of anorthositic rock and minor dark clasts of highland basalts, combined with various mineral and glass fragments, and mixed with a dark matrix of solidified rock powder. This regolith also contains traces of meteoritic material from many impactors, as well as characteristic amounts of solar wind-implanted noble gases. Typical anorthositic regolith breccias are ALH 81005, the first meteorite recognized as a lunar rock, Dar al Gani 262, the first Saharan lunaite, and Dhofar 025, a recent find from Oman. However, some atypical members also contain abundant inclusions of lunar mare lithologies, e.g., the famous Calcalong Creek. It consists of approximately 50% highland anorthosite, 20% KREEP basalt, and 15% low-titanium mare basalt, together with other minerals that are typical for the lunar maria. Calcalong Creek can be regarded as a transitional specimen between anorthositic highland regoliths and mare basalt regoliths. Recent research suggests that it probably formed between the lunar highlands and Oceanus Procellarum, one of the largest basaltic basins on the near side of the Moon.

Impact-melt breccias: The lunaites of this group are polymict breccias displaying characteristics of severe shock-metamorphism, partial melting, and recrystallization, suggesting that they are the products of larger impact events. Compositionally, they are similar to other anorthositic lunaites, and they consist primarily of plagioclase and minor accessory minerals. The members of this subgroup, such as Dar al Gani 400, Dhofar 026, and the beautiful white-colored NWA 482, were all recovered from the hot deserts of Africa and Oman during the last four years.

Fragmental breccias: The rare members of this subgroup are polymict breccias that, at least superficially, resemble anorthositic regolith breccias. They are composed of anorthositic rock fragments and other, mostly felsic, clasts, in a fine-grained matrix of pyroxene and olivine. However, they lack the regolith components and the implanted noble gases characteristic of other regolith breccias. Obviously, they represent the deeper layers of the lunar surface, of which only a few members are known. The only anorthositic fragmental breccia available to the collector is Dhofar 081 and its pairing, Dhofar 280. Both meteorites were found in close proximity to each other, and similarities in structure and composition suggest that they both are part of a single fall. >> top...

DAG 400 Dar Al gani 400 Lunar Anorthositic Breccia found March 10 Th 1998  TKW : 1425 gr
				DAG400- 00 very nice slice of lunar meteorite ! 2.84gr Price on request
DAG400- 01 Nice slice with a rare white inclusion unpubished ! 2.05gr 4920 $
				DAG400- 03 Nice slice !!! 1.59 gr SOLD