Hello list,
after a busy post-Ensisheim week, I have now found the time to prepare for the list slices of the NWA 6963 martian meteorite... This meteorite is realy hard to cut correctly, because easily broken in crumps/dust during process, but shows an amazing matrix when work done ! NWA 6963 shows a minimal weathering (2 of my slices display nice fresh crust), and high shock grade, based on complete transformation of plagioclase to maskelynite (for a total of about 35% !). Its realy looks-like the Shergotty meteorite in structure, and by exemple, the pyroxen chemistry on NWA 6963 is realy close of the first of the shergottite : http://www.lpi.usra.edu/meetings/lpsc2012/pdf/1696.pdf Mineral Compositions and Geochemistry: Electron microprobe analyses reveal two distinct pyroxene compositional trends present in NWA 6963: a pigeonite trend ranging from Fs29Wo11En59 to Fs58Wo16En26 with an average value of Fs39.7±7.7Wo13.0±2.3 (n=108), and an augite trend ranging from Fs21Wo34En45 to Fs39Wo31En30, with an average value of Fs28.1±6.2Wo31.6±1.9. Figure 2 shows that NWA 6963 pyroxene compositions are similar to the pyroxene compositional trends in the Shergotty martian meteorite. Fe/Mn (molar) of pyroxenes has been used successfully to categorize planetary basalts. NWA 6963 pigeonites have Fe/Mn=33±3 and augites with Fe/Mn=31±3 which are consistent with average SNC values. Specimen 0.54g slice - 432$ http://www.wwmeteorites.com/NWA6963/NWA6963-0.54g-01.JPG http://www.wwmeteorites.com/NWA6963/NWA6963-0.54g-02.JPG Specimen 0.58g slice - 464$ http://www.wwmeteorites.com/NWA6963/NWA6963-0.58g-01.JPG http://www.wwmeteorites.com/NWA6963/NWA6963-0.58g-02.JPG Specimen 2.21g slice with two crusted edge - 1660$ http://www.wwmeteorites.com/NWA6963/NWA6963-2.21g-01.JPG http://www.wwmeteorites.com/NWA6963/NWA6963-2.21g-02.JPG Specimen 2.32g slice with two crusted edge - 1740$ http://www.wwmeteorites.com/NWA6963/NWA6963-2.32g-01.JPG http://www.wwmeteorites.com/NWA6963/NWA6963-2.32g-01.JPG Upon request, an 22.65g endcut shows orientation, with flowlines and lips of crust ! Fabien Fabien Kuntz Météorites (ventes, expertise, conférences) Animation scientifique et technique WWMETEORITES (Siret : 511 850 612 00017) www.wwmeteorites.com ______________________________________________ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
