Hello All, I replied in private, and resent my post to the list already, but apparently it didn't go through the first time.
I've seen several identical inclusions in shocked and melted chondrites; the darker material is troilite (iron sulfide) and the lighter material is nickel-iron. It has nothing to do with being the blebs possessing a "precursor" widmanstatten pattern; the lighter and darker areas are simply a dendritic intergrowth of nickel-iron and iron sulfide. And that makes sense - in a shock melt, those elements would tend to aggregate due to their shared chemical affinities. Every metal inclusion in the lighter portion of this stone is similarly structured: http://picasaweb.google.com/MeteoriteKid/Chondrites#5417248216358065954 SEM photo of one of these inclusions from the same stone (NWA 3196): http://picasaweb.google.com/MeteoriteKid/Chondrites#5529579598689715906 I'll leave the SEM photo on picasa for a few days - if anyone wants to see the element map of the same thin section, I'll be able to get ahold of it in a few months - I left my hard copy at home and will need to scan it. The element maps that we made of the same thin section agreed with our hypothesis that the darker areas were in fact iron sulfide - the dark regions were rich in sulfur and depleted in iron and nickel relative to the lighter areas. Some of my other photos also show fracturing and chipping in the darker regions (typical for low-to-moderately shocked troilite), which metallic iron would never show. Regards, Jason On Sun, Oct 17, 2010 at 4:10 PM, m42protosun <m42proto...@t-online.de> wrote: > > Hello lists, with my new Bresser microscope I have detected a structure in > metalflakes which I can not explain. Has any one seen such a structure in > meteorites or documentation where it is explalned? > Look at > > http://s345.photobucket.com/albums/p384/m42protosun/Bubble%20iron/ > > m42protosun > > > > > > ______________________________________________ > Visit the Archives at > http://www.meteoritecentral.com/mailing-list-archives.html > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list ______________________________________________ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
