[meteorite-list] Polymict EUC vs. HOW - NWA1109 ? (& polymict diogenites -NWA 1648)
From: j.divelbiss_at_att.net <j.divelbiss_at_meteoritecentral.com>
Date: Wed May 26 16:29:01 2004 Message-ID: <052620042028.29769.40B4FE0900023208000074492160466648FF8C8C969D939A89969BD1_at_att.net> Thanx Adam...NWA 1648 is a very nice meteorite. Like I said, it(nwa 1648) does not have the look of a eucrite in thin section which would also suggest it is not close to a typical transitional Howardite of 10 to 20% diogenite...as I understand things {ie. limited knowledge for sure :) } Jeff's comment about a contiuous but changing composition range of eucrites to diogenites with Howardites in the middle made me also think that the answer to Stan's question the other day when he was asking about his diogenite pieces that look the same but one has vesicles. Could it just be that the fall that generated those pieces was from a chunk of diogenite that was at a transition zone close to a magam gas release that created the vesicles in some of the material, but not in all of it. Sound like cool stuff Stan. Far out, JD > Dear John and List, > > In simple terms, NWA 1648 was voted in as a polymict Diogenite becuase it is > mostly composed of orthopyroxene and the ratios indicated that several > Diogenitic parent rocks were sampled. > > All the best, > > Adam > > > ----- Original Message ----- > From: <j.divelbiss_at_att.net> > To: "Adam Hupe" <adamhupe_at_comcast.net> > Cc: "Martin Altmann" <Altmann_at_Meteorite-Martin.de>; > <meteorite-list_at_meteoritecentral.com> > Sent: Wednesday, May 26, 2004 10:41 AM > Subject: Re: [meteorite-list] Polymict EUC vs. HOW - NWA1109 ? (& polymict > diogenites -NWA 1648) > > > > Adam, > > > > I have a question along the same lines related to NWA 1648. Could you > summarize the differences between a polymict diogenite (like NWA 1648) and > howardites? Does a polymict diogenite have more (or just more varied) > diogenite in them than the typical howardite? > > > > I just got a thin section of NWA 1648 from Jeff Rowell and it has very > little, if any, needle like plagioclase typcially seen in eucrite material. > Maybe that fact alone is telling me that it is mostly diogenite? > > > > Thanx in advance, > > > > John > > > > > > > > > ______________________________________________ > > > Meteorite-list mailing list > > > Meteorite-list_at_meteoritecentral.com > > > http://six.pairlist.net/mailman/listinfo/meteorite-list > > > > > > ______________________________________________ > Meteorite-list mailing list > Meteorite-list_at_meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list Received on Wed 26 May 2004 04:28:57 PM PDT |
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