[meteorite-list] Greg Hupé's NWA 4883 eucrite
From: bernd.pauli at paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: 12 Dec 2007 18:52:06 UT Message-ID: <DIIE.000000B3000023AA_at_paulinet.de> Greg enthusiastically informed us: "I would like to announce a new and 'unique' maskelynite-rich poly- mict eucrite breccia, NWA 4883. It is a highly shocked eucrite..." That's a truly 'unique' eucrite that was originally thought to be a howardite probably because of all those limpid crystals (cp. provisional classification in the Met.Bull.) and those diverse clasts. What makes it so unique? One key feature surely is *complete maskelynitization* due to *intense shock*. Well, let's have a look. Apart from the Antarctic eucrites, which are unavailable to collectors, there is NWA 2913 but it shows only partial maskelynitization. NWA 3122: this eucrite is highly shocked (S4-5) and thus contains maskelynite! NWA 1981 is S5 and that's why maskelynite is present. NWA 1000: about half of the plagioclase shock-altered to maskelynite NWA 2063: "only" incipient maskelynite (in other words: weakly shocked) NWA 1980: "minor development of maskelynite" NWA 2066: "only" incipient maskelynite As you can see, there are only 3 eucrites (NWA 1981, 3122, 4883) out there that are so intensely shocked that they contain appreciable amounts of isotropic glass (maskelynite) and so I am glad I was able to secure my piece of this HED achondrite! Best pre-Xmas Wishes, Bernd Received on Wed 12 Dec 2007 01:52:06 PM PST |
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