[meteorite-list] Re: 13.5 kg lunar
From: Darren Garrison <cynapse_at_meteoritecentral.com>
Date: Fri May 13 22:35:31 2005 Message-ID: <05pa815madv7us08bdle8cgmum3fack9o9_at_4ax.com> On Fri, 13 May 2005 19:14:24 -0400, "Jeff Pringle" <jpringle_at_mail.stuartdean.com> wrote: >List - >Did anyone notice in the provisional Met Bull 89 that someone found a 13.5 KILO lunar in the Kalahari back in '99? Is that old news? > I certainly didn't know that such a large lunar had ever been found. Even more interesting than the size (to me) is that "the sample does not contain solar wind implanted rare gases". Does that not mean that it had to spend a very short time "in transit" and would have to be from a recent impact? And have to be from a bit of a distance below the lunar surface, because any surface rocks would be exposed to cosmic rays? How short a period would the meteorite need to be exposed to space to not build up solar wind gases? http://epsc.wustl.edu/admin/resources/meteorites/kalahari008_009.html from The Meteoritical Bulletin, No. 89 (preview) Kalahari 009 20.9818?S; 22.9766? E Botswana Found 2004 Febuary 21 Lunar meteorite (basaltic fragmental breccia) A single stone of about 13.5 kg was found in September 1999 by an anonymous finder in front of a sand dune within the Kalahari desert, roughly 50 m apart from Kalahari 001. The rock is different to the Kalahari 001 anorthositic breccia. It has a heavily brecciated texture and is basaltic in composition. The sample does not contain solar wind implanted rare gases (L. Schultz, Mainz). Classification and mineralogy (Anna Sokol and Addi Bischoff, M?n): olivine, Fa50-99.9 (mostly Fa80-95); pyroxene is highly variable (Fs22-67 En10-64 Wo6-41); plagioclase An86-96 (very few plagioclase have more albitic composition, An70-80). The shock stage of the rock is S4; the weathering grade is W1; however, calcite veins are present. Oxygen isotopic composition: d18O = +6.87; d17O = +3.45 (R. N. Clayton, Enrico Fermi Institute, University of Chicago, Chicago, U.S.A.); concentrations of selected elements (XRF or INAA; H. Palme, G. Weckwerth, Institut f?r Mineralogie und Geochemie, Universit?t zu K?ln, Germany) in wt%: Al: 6.76; Mg: 5.14; Fe: 12.47; Ca: 7.66. Zr/Hf = 30.2 and Nd/Ta= 17.4 (M?nker, Institut f?r Mineralogie, Universit?t M?nster, M?nster, Germany). Specimen: Type specimen, 20 g and polished thin section, M?n; main mass, <sic> Received on Fri 13 May 2005 10:44:16 PM PDT |
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