Komplexní petrologický a geochemický výzkum lunárního meteoritu mare-bazaltického složení Northeast Africa 003-A

• Main Author: Haloda, Jakub
• Other Authors: Košler, Jan
• Format: Doctoral Thesis
• Language: English
• Published: 2009
• Online Access: http://www.nusl.cz/ntk/nusl-370412

COMPREHENSIVE PETROLOGICAL AND GEOCHEMICAL STUDY OF LUNAR MARE-BASALT METEORITE NORTHEAST AFRICA 003-A Northeast Africa 003 (NEA 003) is a lunar meteorite found as a two paired stones (6 and 118 g) in Libya in 2000 and 2001. The main portion (~75 vol%) of the 118 g meteorite, used for this study, (NEA 003-A) consists of mare basalt and a smaller adjacent portion (~25 vol%) is a basaltic breccia (NEA 003-B). NEA 003-A has a coarse-grained magmatic texture consisting mainly of olivine, pyroxene and plagioclase. The late-stage mineral association is composed mainly of elongate plagioclase, ilmenite, troilite, fayalite, Si-K-rich glass, apatite and a rare SiO2 phase. Other accessory minerals include ulvöspinel, chromite, and trace Fe-Ni metal. Olivine and pyroxene contain shock-induced fractures, and plagioclase is completely converted into maskelynite. The Fe/Mn values of the whole rock, olivines and pyroxenes, and the bulk-rock oxygen isotopic composition provide evidence for the lunar origin of NEA 003-A meteorite. This is further supported by the presence of Fe-Ni metal and an anhydrous mineral association. NEA 003-A is geochemically and petrographically distinct from previously described mare-basalt meteorites and is not paired with any of them. The petrography and major element composition of NEA...