[meteorite-list] Re: 13.5 kg lunar

[Darren Garrison]

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, Mün): 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 für Mineralogie
und Geochemie, Universität zu Köln, Germany) in wt%: Al: 6.76; Mg: 5.14; Fe: 12.47; Ca: 7.66. Zr/Hf
= 30.2 and Nd/Ta= 17.4 (Münker, Institut für Mineralogie, Universität Münster, Münster, Germany).
Specimen: Type specimen, 20 g and polished thin section, Mün; main mass,   <sic>