[meteorite-list] Olivine Diogenite Naming

From: j.divelbiss_at_att.net <j.divelbiss_at_meteoritecentral.com>
Date: Thu Apr 22 10:21:03 2004
Message-ID: <20030712020630.2AA4F53624_at_pairlist.net>

Adam and Greg,

Thank you for the response and congratulations on being part of making
meteorite history. Sorry if I seem to be trying "gum up the works". I do that
more than I should sometimes. I'll continue this discussion with one more set
of thoughts.

My personal obsession (as a novice) with earth's gabbroic rocks has me quite
interested in this material and how it relates to similar earthly and
meteorite (achondrite) materials. Harzburgite, as I understand it, is 40%
olivine or greater until we call it a Dunite, while Olivine Orthopyroxenite is
less than 40 % olivine, down to about 10 % or so. And then there is plain old
Orthopyroxenite that is 10 % or less in olivine, and covers what we call
Diogenites for meteorites.

So, as far as meteorites go, we have the upper level of "lower crust" in
Diogenites, and much deeper material in what we now call Olivine Diogneites.
My question now is, "I wonder how far down in % of olivine (ie. 10, 20, 30%)
will the description go to be classified as an Olivine Diogenite...and could
there be a need for a classification between Diogenite and Olivine
Diogenite?", if and when we find something in between the present examples
that are classified.


Regards,

Crusty John


  
> Dear John and List Members,
>
> There is not much to worry about as far as confusing a real "Olivine
> Diogenite" with a standard Diogenite if this is what you are asking. A real
> Olivine Diogenite is a Harzburgitic Peridotite not an Orthopyroxenite so any
> scientists should be able to distinguish between the two. I only mentioned
> the real McCoy thing because somebody was trying to pass off a common
> diogenite with an accessory amount of olivine for $500.00 a gram wholesale
> claiming it to be a peridotite. Here is a good link describing the real
> McCoys which compares the four real "Olivine Diogenites" in existence at
> that time, now there is five:
>
> http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1502.pdf
>
> Note the ratio chart. This would serve to easily tell the difference. In
> my opinion the word "Diogenite" should not be used to describe this rarest
> of classes because it is not really a diogenite because it comes from the
> mantle. We believe at this point changing the name would add even more
> confusion. Hey, this is a history making class, time to celebrate!
>
> All the best,
>
> Adam
>
>
>
> ----- Original Message -----
> From: <j.divelbiss_at_att.net>
> To: "Adam Hupe" <adamhupe_at_comcast.net>
> Cc: <meteorite-list_at_meteoritecentral.com>
> Sent: Friday, July 11, 2003 4:45 PM
> Subject: Re: [meteorite-list] Olivine Diogenite Naming
>
>
> > Adam,
> >
> > The naming logic seems reasonable.
> >
> > However, does this mean we could one day have an olivine-rich Diogenite
> that
> > is not an Olivine Diogenite?
> >
> > Without getting into to much detail, what general criteria will it take to
> be
> > called an Olivine Diogenite?
> >
> > Regards,
> >
> > John
> > >
>
>
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Received on Fri 11 Jul 2003 10:06:29 PM PDT