doi:

DOI: 10.3724/SP.J.1084.2013.00352

Chinese Journal of Polar Research (极地研究) 2013/25:4 PP.352-361

THE PETROLOGY AND MINERALOGY OF LUNAR METEORITE EET 96008 FROM ANTARCTICA


Abstract:
Meteorite EET 96008 is a lunar basaltic breccia collected from the Elephant Moraine region of Antarctica. The petrography and mineralogy of EET 96008 is described in detail. The meteorite has a typical breccia texture consisting of sub-angular clasts (50.2 vol%) and matrix (49.8 vol%). The clast size is generally between 0.1 and 2 mm. The meteorite clast types are divided into three main categories: minerals, rocks and glassy clasts. (1) Mineral clasts include pyroxene, olivine, feldspar and quartz. (2) Rock clasts are mainly granulite, basic rock and noritic anorthosite. (3) Glassy clasts are anorthositic. In grain size, the clasts and matrix vary gradually. The matrix consists of mineral and glassy clasts that are < 0.1 mm in size. The meteorite contains a variety of pyroxenes that cover most of the pyroxene quadrilateral (Fs17.95-58; Wo3.95-45.17; En3.45-79.07). They also possesses extensive exsolution lamellae that are up to 1 μm in width. Fe content in the olivine is relatively high, and can be mainly divided into two areas: Fa50-70 and Fa80-95. The average Fa is 71.8. The plagioclase component in EET 96008 is enriched in Ca. Some plagioclases have been converted into maskelynite. EET 96008 consists of the same lunar basaltic breccia as QUE 94281. They share a similar texture and mineral assemblage. Their clear differences in clast type and the mineral composition of olivine indicate that they are not paired and may came from a different source. EET 96008 has the three typical shock-induced darkened areas, and a great deal of glassy clasts and shock pockets, suggesting that its shock stage should be above S5. The study of the phenomenon of ferrosilite decomposings into hedenbergite-fayalite-quartz in the meteorite will provide insight for determining the shock history of the lunar surface.

Key words:lunar meteorite, EET 96008, lunar breccia, petrography, mineralogy

ReleaseDate:2014-07-21 16:59:38



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