[meteorite-list] Nwa 7034

From: Carl Agee <agee_at_meteoritecentral.com>
Date: Sat, 26 Jan 2013 21:38:11 -0700
Message-ID: <CADYrzhpohtTAC7JMdvEPEf9tkgirPpwM7cttXcXEFvtWwKE=Tw_at_mail.gmail.com>

Hi Jeff and all you Nomenclature Enthusiasts out there:

I think the martian meteorite names do serve a useful purpose, they
are a sort of short-hand, so that you don?t have to be an igneous
petrologist to know that one type of martian is different from
another. So when we say a martian meteorite is a ?NWA7034-ite?, or
?blackbeauty-ite?, or a ?saharite? or whatever name you want to pick,
we are implicitly talking about a breccia, that is water-rich, alkali
basalt, with higher-than-SNC oxygen isotope values, ~ 2 byo, etc. For
example, like it or not, when we say ?Allan Hills? the first thing
comes that comes to mind is ALH 84001. When you say orthopyroxenite
maybe not so much. If it?s such a great idea to do away with martian
types, why don?t we go ahead and do away with all the carbonaceous
chondrite groups like CI, CM, CV, etc. and just call them all
carbonaceous chondrites, that of course have a wide range of
compositions, textures, mineralogies etc.? Meteoritics isn?t the only
science that has colorful nomenclature. Mineralogists still like to
name new minerals after famous mineralogists, instead of just naming
them by their chemical composition or crystal structure.

Carl Agee

-- 
Carl B. Agee
Director and Curator, Institute of Meteoritics
Professor, Earth and Planetary Sciences
MSC03 2050
University of New Mexico
Albuquerque NM 87131-1126
Tel: (505) 750-7172
Fax: (505) 277-3577
Email: agee at unm.edu
http://meteorite.unm.edu/people/carl_agee/
------------------------------
Message: 7
Date: Sat, 26 Jan 2013 15:27:06 -0500
From: Jeff Grossman <jngrossman at gmail.com>
Subject: Re: [meteorite-list] Nwa 7034
To: meteorite-list at meteoritecentral.com
Message-ID: <51043C1A.9040809 at gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Meteorite group names are not invented by NomCom, and certainly not by
NASA.  The come from usage in the scientific literature.
I think we have to remember why names like shergottite and nakhlite came
into being.  Scientists like to group similar things to help bring order
to chaos.  When you know next to nothing, you start by putting similar
things together that you can study as a group.  Once you learn more,
relationships may be found among them.  In this case, several groups
plus a few oddballs seem to share a common origin: Mars.  At this point,
it doesn't really help anything to continue to generate trivial names
for new groupings.  The big advance has been made, and we can call them
Martian meteorites.  That means it is time to start treating all of
these meteorites like we do geological specimens on Earth, using
standard kinds of lithologic names.  I know the old trivial names will
die hard, and a term like shergottite will be with us for a long time.
But there is no good reason to continue creating new trivial names.  ALH
84001 need only be called a Martian pyroxenite (assuming this is the
best rock name for it).  If 10 more of these are found, they only need
to be called Martian pyroxenites; there is no need to define a useless
new term like "allanhillsites."  The same goes for NWA 7034, which we
can call a Martian alkali-rich basalt, or whatever Carl says it is.
Note that nomenclature for lunar meteorites was never burdened with
trivial names, as there were no famous historical falls or finds.  After
30 years, lunar anorthosite meteorites are still just called lunar
anorthosites.  Scientists don't need to put them in a trival category
like "calcalongites" to distinguish them from the basaltic
"kalahariites"... this would only obscure what we know about all of
these, and nobody will ever do it.
So let's forget about inventing terms like saharanite or morrocanite or
allanhillsite or whatever.  (And while we're at it, let's consider
forgetting about shergottite, chassignite and nakhlite.)  They're
unnecessary and useless to science.

Received on Sat 26 Jan 2013 11:38:11 PM PST