Geochemistry of magnesian granulites in feldspathic lunar meteorites Allan Hills A81005 and Dhofar 309

[摘要] Magnesian granulites in Allan Hills A81005 and Dhofar 309 may possess the geochemical signature of the Moon;;s Feldspathic Highlands Terrane (FHT). Previous work on Apollo granulites suggests the presence of a high Mg/Fe, feldspathic, rare earth element-poor component in the lunar crust. Remote sensing data have strengthened this inference, showing such a composition is widespread in the FHT. My research extends the characterization of magnesian granulites to those in feldspathic lunar meteorites, which are essentially unstudied. I reconstruct the bulk chemistry of granulites in thin section by combining mineral proportions (retrieved from element X-ray maps via multispectral image classification software) and mineral compositions. This virtually non-destructive method is useful for rare samples and fragments in thin section. Magnesian granulites in Allan Hills A81005 and Dhofar 309 share similar major and trace element compositions. As these two meteorites are not paired, their comparable geochemistry may be representative of the average FHT.

[发布机构] Rice University

[效力级别] Geochemistry