[meteorite-list] What It is!
From: Dave Freeman mjwy <dfreeman_at_meteoritecentral.com>
Date: Thu Jun 16 09:47:12 2005 Message-ID: <42B182E9.3000204_at_fascination.com> Gabbro it is....soon as gabbro was mentined, I realiized that basalt was not due to cooling rate involved.. But what of my olivine "gabbro"???????????? Not heard of that before. Gabbronic-olivine? More coffee this morning! Dave F. Robert Verish wrote: >Yes, ladies and gentleman, we have a winner! > >Norm is right about "It" being a "gabbro". > >Sorry Dave, but I live fairly close to Acton CA and I >can confirm that it is situated at the foot of a >mountain of gabbroic rock of the San Gabriel Mtns >Anorthosite Ultramafic Complex. It wouldn't take much >effort to find a rock like those in the auctions. >Predominantly titano-magnetite (ilmenite) with iron- >stained andesine plagioclase and accessory apatite and >zircon. > >The next time you're in SoCal I can show you a >locality where we can find purple anorthosite and 2cm >long zircons! :-) > >Bob V. > >-------------------------- >[meteorite-list] What is It? >Norm Lehrman nlehrman at nvbell.net >Wed Jun 15 23:01:28 EDT 2005 > > >Slow down Dave, > >I didn't say it is a winner; I just don't know what >it is. I can't seem to get the picture back up (I >think the auction has been cancelled), but it looked >to me like all the phases were very coarsely >crystalline. In this case, metal or no metal, it >couldn't be a basalt (which is by definition aphanitic >except for possible phenocrysts). > >With slower crystallization, you can get gabbros and >other coarsely crystalline ultramafics with segregated >sulfides, but once again, the rapid crystallization >leading to basalt formation has little chance to >segregate anything beyond micro-blebs of sulfide. > >I can't believe it could be a basalt. > >Norm > > >______________________________________________ >Meteorite-list mailing list >Meteorite-list_at_meteoritecentral.com >http://six.pairlist.net/mailman/listinfo/meteorite-list > > > > Received on Thu 16 Jun 2005 09:47:21 AM PDT |
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