[meteorite-list] Primitive Achondrite Question

From: Alan Rubin <aerubin_at_meteoritecentral.com>
Date: Tue, 6 Dec 2011 11:01:50 -0800
Message-ID: <5880BA263EF84693BD950B512F4C3876_at_igpp.ucla.edu>

Classifications are just a way of making sense of the world by putting
diverse objects into tidy categories. Even though real-world objects don't
always fit (is light a wave or a particle?), good classifications last
longer than interpretations. For example, the Linnaeus classification
system was developed from a creationist perspective but is used today by
every evolutionary biologist. So, to answer your question, classification
is an end in itself -- it certainly helps in understanding relationships
among diverse objects. But classification is not the only end --
understanding the origins of objects is also rather important, but because
we have incomplete knowledge of objects, our interpretations are always
tentative, subject to revision when new data are acquired. Classifications
should be longer-lasting.
    As an aside, if you are interested in bad classification systems for
meteorites, look at George Merrill's "The Story of Meteorites" from 1929:
There are andrites, eukrites, shergottites, howardites, bustites,
chassignites, chladnites, amphoterites, howarditic chondrites, white
chondrites, intermediate chondrites, gray chondrites, black chondrites,
spherulitic chondrites, crystalline chondrites, carbonaceous chondrites,
orvinites, tadjerites, ureilites, lodranies, grahamite mesosiderites,
siderophyrs, and more. Some of the groups are still recogniable, others
less so. The problem was that the knowledge base at the time was
insufficient to distinguish essential from secondary properties. Similar
problems arose among classification schemes of living creatures and
especially fossils.

Alan


Alan Rubin
Institute of Geophysics and Planetary Physics
University of California
3845 Slichter Hall
603 Charles Young Dr. E
Los Angeles, CA 90095-1567
phone: 310-825-3202
e-mail: aerubin at ucla.edu
website: http://cosmochemists.igpp.ucla.edu/Rubin.html


----- Original Message -----
From: "MexicoDoug" <mexicodoug at aim.com>
To: <raremeteorites at yahoo.com>; <meteorite-list at meteoritecentral.com>
Sent: Tuesday, December 06, 2011 9:31 AM
Subject: Re: [meteorite-list] Primitive Achondrite Question


> Adam wrote:
>
> "NWA 3133 is a CV Primitive Achondrite"
>
> Hi Adam, thanks ... The asteroid belt ought to be called the asteroid zoo!
>
> The question I have on this one, if CV is for certain, would be whether it
> is the result of a collision with a typical CV type, or is it certain that
> it is a fully baked CV (what happened to the possible CAI's - are there
> any, or is the CV possibly just impact regolith?), or, whether some
> innocent CV got hot all by itself.
>
>
> Kinest wishes
> Doug
>
> (Why does my wallet retract down my pocket every time ths stuff comes up!)
>
>
>
>
> -----Original Message-----
> From: Adam Hupe <raremeteorites at yahoo.com>
> To: Adam <meteorite-list at meteoritecentral.com>
> Sent: Tue, Dec 6, 2011 11:47 am
> Subject: Re: [meteorite-list] Primitive Achondrite Question
>
>
> Doug wrote: I can't wait until someone turns up a CV6+. Theoretically,
> there is
> no reason to
> bar the possibility,, or is there...
>
> NWA 3133 is a CV Primitive Achondrite
>
> All of these oxygen isotope compositions
> plot on the CV3 mixing line, suggesting that this achondritic meteorite
> has
> affinities with CV chondrites (Irving et al., 2004).
>
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Received on Tue 06 Dec 2011 02:01:50 PM PST