Hello Graham, All, Well, there's always Albion, though that's quite a different beast. I believe the druzy vugs found in that are accepted to be a product of impact melting, as per Buchwald. By the look of the specimen, I think it's safe to say that the bubbles are the result of an accumulation of melt on the rear of a specimen that maintained a stable flight for an extended period of time - much as stony meteorites do, but for a longer period of time than is commonly seen. Here's a link to the first photo of the stone in my album:
http://www.flickr.com/photos/cameteoritefinder/2335700193/in/photostream/ To see the rest, just look at the pictures on the right and click on the following photos.. Regards, Jason On Tue, Nov 17, 2009 at 5:10 PM, <[email protected]> wrote: > Amazing piece with bubbles Jason, > > Been trying to figure out how that could happen. It does not look like it > happened due to melt during the fall but more like a feature from pre-entry, > exposed after fragmenting. > > What are your thoughts...I can't think of any other irons with bubbles. > > Regards > > Graham > > ---- Jason Utas <[email protected]> wrote: >> Maurizio, Graham, Jeff, Fred, Darren, All, >> I think Darren's hit on the fact of it - as I noted in my original post: >> >> "Many batches of shrapnel do appear to be somewhat ablated due to the >> method by which they have been cleaned (tumbling with ball bearings >> tends to wear corners down and gives the false impression of surfaces >> having melted)." >> >> I think this is what you're noting, Fred - if you'd care to send some >> pictures I'd be more than glad to have a look, but I'm fairly certain >> that what you're seeing are mere remnants of the cleaning process. >> Which isn't to say that shrapnel can't exhibit folded over rims, etc, >> but such features are morphologically distinct from roll-over lipping >> that we see in fusion crusts; it's one thing to fold a torn edge over, >> and another matter entirely to force molten material over an edge to >> form a lip. >> I can't comment on the other features you've noted without seeing >> pictures, but I would note that many Sikhotes exhibit crater-like >> features that formed due to spallation caused by rust, which could >> also be mistaken for bubbling. >> I have only ever seen true bubbles on one Sikhote (and it is the only >> *iron* meteorite that I've ever seen that actually showed true >> bubbles) in my entire life; here's a photo. >> >> http://www.flickr.com/photos/cameteoritefinder/2335708513/sizes/l/ >> >> Regards, >> Jason >> >> On Tue, Nov 17, 2009 at 12:08 PM, <[email protected]> wrote: >> > Darren, I just looked at 119 individual pieces of shrapnel fragments >> > under a microscope. They are rather small and range in size from 30 grams >> > to less than one gram. It looks to me that every one of them shows some >> > feature of melting. many have roll over rims, melted grooves, fusion crust >> > with impact pits, bubbly crust on backside of oriented pieces. I doubt >> > that any of these features were produced by tumbling. >> > Regards, Fred >> > -------------- Original message ---------------------- >> > From: Darren Garrison <[email protected]> >> >> >> >> I was under the impression (read it somewhere) that most modern=collected >> >> Sikhote-Alin fragments are rusty and are cleaned in rock tumblers. If >> >> so, could >> >> not that dull/round formerly sharp edges and make them look "melted"? >> >> ______________________________________________ >> >> http://www.meteoritecentral.com >> >> Meteorite-list mailing list >> >> [email protected] >> >> http://six.pairlist.net/mailman/listinfo/meteorite-list >> > >> > >> > >> > >> > >> > ______________________________________________ >> > http://www.meteoritecentral.com >> > Meteorite-list mailing list >> > [email protected] >> > http://six.pairlist.net/mailman/listinfo/meteorite-list >> > >> ______________________________________________ >> http://www.meteoritecentral.com >> Meteorite-list mailing list >> [email protected] >> http://six.pairlist.net/mailman/listinfo/meteorite-list > > ______________________________________________ http://www.meteoritecentral.com Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
