Granulite Clasts of Intermediate Mg* in Lunar Meteorite Alha 81005: Chemical Compositions and Origins
نویسندگان
چکیده
Lunar highland meteorites contain fragments of metamorphic granulites with a wide range of Mg* (molar Mg/(Mg+Fe)) [1], between that of Mg-suite plutonics and magnesian anorthositic granulites (MAG), and those of ferroan anorthosites (FAN), Figure 1 [2,3]. The intermediate-Mg* granulites have been inferred (explicitly or implicitly) to represent mixtures of FAN and MAG or Mg-suite rocks. To test this inference, we analyzed granulite clasts in lunar meteorite ALHA 81005, which include MAG, FAN composition, and those of intermediate Mg*. Most of the intermediate-Mg* granulites cannot be simple binary mixtures of MAG and one FAN composition. Thus, the intermediate-Mg* granulites probably formed from several precursor materials, and likely by several mechanisms, including solid-state diffusion.
منابع مشابه
New Insights into the Complex History of Lunar Highlands: Alha 81005 under Reinvestigation
Introduction: Lunar meteorites come from random sites on the Moon (including areas not visited by Apollo or Lunar missions) and so are crucial for understanding the development of the whole moon, and as ground truth for lunar remote sensing. Data from the Lunar Prospector and Clementine spacecraft show that, relative to the Apollo and Luna landing sites, most of the lunar surface has low abunda...
متن کاملUnique Spinel-rich Lithology in Lunar Meteorite Alha81005: Origin and Possible Connection to M Observations of the Farside Highlands
Introduction: The discovery of spinel rich rock on the Earth’s Moon, detected by the M near-IR mapping spectrometer on the Chandrayaan-1 spacecraft [1] is among the most intriguing discoveries in a time filled with lunar revelations (e.g., [2]). The M spectrometer discerned several areas on the rim of the far-side Moscoviense basin which had near-IR reflectance spectra characteristic of abundan...
متن کاملA new lunar high-Ti basalt type defined from clasts in Apollo 16 breccia 60639
This paper reports the detailed examination of three basalt clasts from Apollo 16 breccia 60639 that represent a new variant of high-Ti basalt returned from the Moon by the Apollo 16 mission. Mineral chemistry and whole-rock analyses were conducted on aliquots from three clasts (breccia matrix, basalt, and basalt + breccia matrix). The basalt clasts, which are not overtly porphyritic, contain c...
متن کامل05035 and Meteorite Hills 01210 : Two Basaltic Lunar Meteorites
Introduction: The lunar meteorites Miller Range 05035 (MIL) and Meteorite Hills 01210 (MET) were collected during the 2005 and 2001 ANSMET (Antarctic Meteorite Search) field seasons [1,2]. MET is a 22.8 g regolith breccia composed primarily of basaltic material [3-6]. MIL is a 142.2 g coarse-grained basalt [2]. The bulk composition, mineral assemblage, and texture of MIL is similar to lunar met...
متن کاملMgm Deconvolution of Reflectance Spectrum of the Y981031 Lunar Meteorite
Introduction: We report Modified gaussian model (MGM) deconvolution analyses [2] of reflectance spectrum of the Yamato (Y) 981031. Petrological characteristics of Y981031 had already reported [1]. Absorption features derived from the MGM deconvo-lution are compared with the petrological characteristics of Y981031, and implication of the absorption features are discussed. Finally, we propose sou...
متن کامل