[meteorite-list] FW: Rocks from Space Picture of the Day -May 8, 2010
From: Wayne Holmes <holmesw_at_meteoritecentral.com>
Date: Sun, 9 May 2010 16:07:16 -0700 Message-ID: <007d01caefcc$5f0720f0$0200a8c0_at_Buckaroos> Hello Larry and all. Here are more of the train wreck specimens I found a mile from the tracks in the field. Will keep my fingers crossed for your yours. Best regards. Wayne http://www.meteoritesrock.com/franconia%20irons.html ----- Original Message ----- From: <thetoprok at aol.com> To: <meteorite-list at meteoritecentral.com> Cc: <mojave_meteorites at cox.net> Sent: Sunday, May 09, 2010 9:05 AM Subject: Re: [meteorite-list] FW: Rocks from Space Picture of the Day -May 8,2010 > Hi Rob, List, > > I'd like to address a couple of points Rob made. I have great repect > for you Rob, you are one smart dude, no doubts here! > > No disrespect intended to anyone out there, we all have opinions and > that's what makes it all so fun! (Sorry to Phil and Warren for my > "full of it" comment last night, I was having fun at your expense and > should not have > made the comment, nothing personal.) > > First, I don't believe anyone here thinks of the Franconia irons as an > independent fall. It is widely known and understood that these are > spalled out of the H chondrite. If my memory serves me correctly there > were a few of you real smart guys out there that were adament opponents > of a meteoritic origin at all concerning these tiny irons. A bunch of > us that were in the field finding these little oriented beauties > couldn't understand this position and I was truly starting to doubt > some of the science/scientists. I'm glad it was straightened out and > the truth acknowledged. I don't know if I agree with them getting their > own classification but something needed to be done to acknowledge the > unusual circumstances and unlikely event that created these. That being > said, let's look closely at the irons, they may tell the whole story if > we > can learn to read them. > > Rob says they didn't have the opportunity to experience "high altitude, > high velocity ablation." I've posted some more pictures to my > photobucket site. Though they are not the best pic's they do > demonstrate the fact that at least some of these experienced some > serious ablation, from flow lines to roll over lipping, bullet shapes > and BB's. That in my > opinion constitutes high altitude, high velocity ablation. These shapes > did not occur some time after the stone was on the ground and the metal > weathered out, nor did the shapes occur during dark flight, no way no > how. > > As far as weathering away over the long period of time since the fall, > I have no answer for that. However, it is a fact that many of the irons > that have been found are smaller than .1 gram. I've found them myself > and I've looked at other peoples finds that are very tiny. Somehow they > are not weathering into oblivion. Perhaps this is another aspect of > these irons that is not yet understood. Some are more weathered than > others. They range in color from gun barrel blue to orange rust, some > are black, others are brown, with different degrees of weathering > apparent. > > I believe it's important to know the true answer because if it is a > meteorite it should shed light on the impact pits on Sikhote Alin and > other irons. Some people think that impurities popped out of the iron, or > in the case of Franconia, that chondrules popped out, while others see a > splash as if something impacted it. My little enigma may answer that > question if it is proven to be of extraterrestrial origin. That would be a > contribution to the science. > > If the RFSPOD object is a meteorite I think it is imperative that that > be known. I feel an obligation to put it to the test and I'm close to > having a SEM reading. I'll certainly inform the list when the results > come in. > > Whatever the result is this has been a positive thread that inspires > people to think and have constructive conversation and debate, what > else could you ask for? > > http://s934.photobucket.com/albums/ad190/alienrockfarm/ > > Best Regards to All > Larry > > > -----Original Message----- > From: Rob Matson <mojave_meteorites at cox.net> > To: meteorite-list <meteorite-list at meteoritecentral.com> > Sent: Sun, May 9, 2010 3:19 am > Subject: Re: [meteorite-list] FW: Rocks from Space Picture of the Day > -May 8, 2010 > > Hi All, > > Short opinion: manmade. > > Reasoning: the inability to produce such a form purely through > atmospheric ablation. Just to remind everyone, all of the > so-called Franconia irons are nothing more than chondritic > iron that has separated from an H-chondrite fall -- either > during flight, or by terrestrial weathering processes on the > ground. Thus it has always bothered me that these irons were > given a separate meteorite name from the ubiquitous H-chondrites > at Franconia from which they derive. If my information is > outdated on this subject, someone please let me know. But many > (most?) of the people I know who have hunted Franconia and > found these irons do not pretend that they are from a separate > iron fall -- they all accept that the iron nuggets were > spalled from an H-chondrite. > > So, getting back to Larry's unusual, tiny iron find. If this > iron did not start at the top of the atmospere as a very tiny > piece of iron, there would be no way to ablate it, let alone > punch a hole through it. Since the Franconia irons were once > part of a massive chondritic meteoroid, there was no opportunity > for these irons to experience independent, high altitude, high > velocity ablation. Their ablation history wouldn't have started > until the main H-chondrite body had fragmented on a gigantic > scale (e.g. terminal burst), which of course would have > occurred at comparatively low altitude. > > On a final note, the H-chondrite fall at Franconia was not > a recent one. While this part of NW Arizona receives little > seasonal rainfall, I don't imagine that a 0.1-gram piece of > iron could survive more than a century. But a manmade piece > of iron, dropped there in the last 50 years, might possibly > survive terrestrial weathering. > > I would love nothing more than for Larry's find to have an > extraterrestrial origin; but the physics and history of finds > at Franconia argue strongly against it. > > Best wishes, > Rob > > ______________________________________________ > Visit the Archives at > http://www.meteoritecentral.com/mailing-list-archives.html > Meteorite-list mailing list > Meteorite-list at 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 at meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list Received on Sun 09 May 2010 07:07:16 PM PDT |
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