[meteorite-list] Nwa 7034

[Jeff Grossman]

There are two reasons why we can't get rid of carbonaceous chondrite 
group names.  First, unlike Martian meteorites, we don't know where C 
chondrites came from.  We can't point to a single asteroid as the source 
for any of them, let alone all of them.  So the group names are still 
serving their basic purpose of ordering the chaos.  Second, the only 
language we have to describe the rocks known as chondrites is by their 
group names.  They can't be described with standard rock nomenclature. 
So this is not a fair comparison.

I didn't say Martian meteorite names were not useful.  I said they were 
archaic, historical artifacts.

Jeff

On 1/26/2013 11:38 PM, Carl Agee wrote:
> 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
>
>