[meteorite-list] Weird inclusion in NWA 2086 CV3
From: Galactic Stone & Ironworks <meteoritemike_at_meteoritecentral.com>
Date: Wed, 11 Aug 2010 00:02:44 -0400 Message-ID: <AANLkTimH=Y3TCts5nE-0an+RB8Nok6Fmo1kGGh1144Fa_at_mail.gmail.com> Wow, see this photo - http://www.meteorite-house.com/MHContentFiles/MHmetPix/PicStoneCHotherNWA208612.html Andreas' specimen does have a clast like mine! Notice the close-up of the clast in his piece. It is very similar to the light-colored regions in my stone. There is even chondrule deformation. :) On 8/10/10, Galactic Stone & Ironworks <meteoritemike at gmail.com> wrote: > Hi Jason and List, > > Jason makes a great point about this being an "inclusion within an > inclusion". These specimens were taken from a small, jagged, fragment > that was obviously a remnant of a larger mass. Before that mass > fragmented (either in flight, on impact, or through weathering), it > was presumably a whole stone with a more representative lithology of > this meteorite. This light-colored region with squashed chondrules > and it's brown "inclusion" was previously embedded in the larger > stone. It would have been great to see a slice of the whole stone > that this fragment came from. > > As for being NWA 2086 or not, I would question it also if presented > with my initial post and photos. But, I did cut a larger batch of > this material and all of it (except for this fragment) looked exactly > like typical NWA 2086 - darker matrix, more spherical chondrules, more > colorful chondrules, CAI's, etc. Also, I asked my source about the > chain of provenance regarding this batch and I was told that it came > directly from a very respected source. I don't want to name drop, but > contact me off-list if curious. The provenance is very solid. So I > am very confident that this material is indeed NWA 2086. > > The question in my mind now is about the brown inclusion - is it a > product of weathering/oxidation, or was it originally present in the > meteorite? If the latter, then what is it? This question will be > answered soon, because one List member has offered to thin-section > this material for me and another list-member with thin-section > experience purchased the largest piece. So, two different veteran > list members are going to make qualitative examinations and analysis > of these specimens in the future. And I hope they will share the > results with us. > > Also, for those who might inquire, this "brown inclusion / light > lithology" material is sold out. I kept one slice and sold the > remaining pieces. All I have remaining are small crumbs and a few > sub-gram pieces that show some chondrules. The slice I kept will > likely become another thin-section, pending further discussion. > > I did some looking on the web, and I found a single photo of NWA 2086 > that has a clast that somewhat resembles the lighter lithology in my > specimens. In this linked photo, look in the lower left-hand portion > of the specimen, near the 7-oclock position. You will see a clast on > the edge that is a different lithology than the rest of the specimen. > The clast is similar in color to my specimens, but it lacks the > squashed ellipsoidal chondrules. > > http://www.meteorite-house.com/MHContentFiles/MHmetPix/PicStoneCHotherNWA208611.html > > I examined my slice under the microscope at 60x tonight, and the > matrix in the light-colored area looks "stippled". It appears to be > composed of tiny black dots set into a whitish background matrix. > Whatever it is, it is very fine-grained compared to the darker > lithology that is seen on the same specimen. I am glad there is the > boundary line and region of common NWA 2086 lithology in these pieces, > because it provides a good contrast for comparing the two lithologies. > > Best regards, > > MikeG > > ------------------------------------------------------------ > Mike Gilmer - Galactic Stone & Ironworks Meteorites > http://www.galactic-stone.com > http://www.facebook.com/galacticstone > ------------------------------------------------------------ > > > > On 8/10/10, Jason Utas <meteoritekid at gmail.com> wrote: >> Hello Jeff, All, >> The only reason that I assumed that this slice *might* be a piece of >> NWA 2089 is because of that "dark corner" - it's the only part of this >> stone that looks *like* NWA 2086. >> The light lithology that you say looks like NWA 2086 looks very unlike >> other samples of 2086: >> >> http://www.aerolite.org/prizes/nwa-2086.htm >> >> http://www.meteoriteguy.com/catalog/nwa2086.htm >> >> http://www.meteorite-times.com/Back_Links/2008/march/Accretion_Desk.htm >> >> So what we're looking at here, if it's a piece of NWA 2086, is a slice >> comprised almost entirely of a light clast that is in no way typical >> of most NWA 2086 specimens. >> >> That strange brown thing that everyone's arguing about has chondrules >> in it. If it has discolored differently than the rest of the >> meteorite due to weathering or some other process, it would still >> point towards that area being composed of a different material (why >> would it weather differently if it were made of the same stuff?). >> Given that it seems to have a lesser concentration of chondrules >> within it (as opposed to the rest of the lighter clast), I would >> assume that it is indeed foreign meteoric material. >> >> But CV3's have strange C-type inclusions in 'em all the time. What's >> the biggie? >> ...It's an inclusion within an inclusion? That's cool... >> >> Regards, >> Jason >> >> On Tue, Aug 10, 2010 at 1:07 PM, Jeff Grossman <jgrossman at usgs.gov> >> wrote: >>> My money's on terrestrial weathering as the cause of the brown area, >>> although there is a clear lithologic boundary on the right side of >>> photo: >>> http://i268.photobucket.com/albums/jj24/Meteoritethrower/2086-slice-weird-1.jpg. >>> >>> Jeff >>> >>> >>> On 2010-08-10 2:22 PM, Galactic Stone & Ironworks wrote: >>>> >>>> Hi Bernd and List, >>>> >>>> That's funny you mention that because Bob King also raised the >>>> possibility of phyllosilicates. I took some more photos of the >>>> specimen that show a better representation of what the specimen looks >>>> like. You can also see a distinct boundary line between the typical >>>> NWA 2086 lithology (darker matrix) and the strange "lighter colored" >>>> lithology that the majority of this stone has. One area near the end >>>> shows the type of matrix we expect from NWA 2086. >>>> >>>> The brown inclusion does not show any features under it or through it, >>>> except in one small spot where two chondrules appear to be immersed in >>>> it, while the rest of the inclusion flows around the chondrules like a >>>> river flows around islands. >>>> >>>> http://i268.photobucket.com/albums/jj24/Meteoritethrower/endcut-519-a.jpg >>>> >>>> http://i268.photobucket.com/albums/jj24/Meteoritethrower/endcut-326-1.jpg >>>> >>>> >>>> http://i268.photobucket.com/albums/jj24/Meteoritethrower/2086-slice-weird-1.jpg >>>> >>>> Best regards, >>>> >>>> MikeG >>>> >>>> ------------------------------------------------------------ >>>> Mike Gilmer - Galactic Stone& Ironworks Meteorites >>>> http://www.galactic-stone.com >>>> http://www.facebook.com/galacticstone >>>> ------------------------------------------------------------ >>>> >>>> On 10 Aug 2010 15:21:51 UT, bernd.pauli at paulinet.de >>>> <bernd.pauli at paulinet.de> wrote: >>>> >>>>> >>>>> >>>>> http://i268.photobucket.com/albums/jj24/Meteoritethrower/2086-inclusion.jpg >>>>> >>>>> Hello All, >>>>> >>>>> Michael G. wrote: >>>>> >>>>> "So I am thinking that there must have been a surface fracture that >>>>> extended >>>>> down into >>>>> the interior of the stone. Weathering products intruded through this >>>>> crack >>>>> and the brown >>>>> 'inclusion' is probably just a clay-like replacement mineral." >>>>> >>>>> "clay-like" => phyllosilicates are clay minerals! >>>>> >>>>> .. and *if* it is preterrestrial, this might be an extended >>>>> area of phyllosilicates, saponite, smectite or something! >>>>> >>>>> Cheers, >>>>> >>>>> Bernd >>>>> >>>>> >>>>> >>>>> ______________________________________________ >>>>> 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 >>>> >>>> >>> >>> >>> -- >>> Dr. Jeffrey N. Grossman phone: (703) 648-6184 >>> US Geological Survey fax: (703) 648-6383 >>> 954 National Center >>> Reston, VA 20192, USA >>> >>> >>> ______________________________________________ >>> 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 >> > -- ------------------------------------------------------------ Mike Gilmer - Galactic Stone & Ironworks Meteorites http://www.galactic-stone.com http://www.facebook.com/galacticstone ------------------------------------------------------------Received on Wed 11 Aug 2010 12:02:44 AM PDT |
StumbleUpon del.icio.us Yahoo MyWeb |