[meteorite-list] Hyphens / Slashes

From: j.divelbiss_at_att.net <j.divelbiss_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:52 2004
Message-ID: <031920042127.13980.1279_at_att.net>

Bernd. Dave, Joern and others,

Bernd, thanx for the previously submitted info from Jeff on slashes and dashes.

That should certainly clear it up the confusion, right Dave. :)

John

BTW: Joern...in all seriousness I really appreciate you responding to this thread.


> > For chondrite groups, petrologic types, shock stages, and weathering
> > grades, slashes (e.g., H5/6) indicate transitional assignments. Hyphens
> > in petrologic type assignments for chondrites (e.g., H5-6) indicate the
> > range of types observed in breccias. Group names such as "L(LL)" indicate
> > uncertain assignments, with the less probable group in parentheses.
>
> Hello All,
>
> I was waiting for Jeff Grossman to chime in here, because
> on Monday, 07 Sep 1998, Jeff wrote to this to the List (excerpts):
>
> Right now we have a literature polluted with this and other nomenclatures
> (like using a "/" instead of a "-" for the same thing), and the community has
> no way of looking at a catalog and knowing what's what. The Meteorite
> Nomenclature committee has no jurisdiction over meteorite classification;
> it just oversees meteorite names. It's just a mess.
>
> There is NO convention for naming brecciated chondrites. Many, including the
> group at Muenster, like to use a slash to separate components of a breccia.
> However, nobody has ever written a paper on the subject, and the rules are up
> for grabs. I happen to be of the opinion that the slash is ridiculous for many
> reasons,
> including the one brought up here: we will always need to be reclassifying
> breccias
> whenever somebody finds a new lithology among the clasts. This is not feasible.
>
> These parentheses are used by some researchers when they cannot determine with
> certainty the group assignment of a meteorite. L(LL)3 means that they lean
> towards
> L3, but it could be an LL3. Indeed, it is very difficult to differentiate
> between L3 and LL3
> chondrites, as they may have similar sized chondrules, similar metallography,
> similar
> silicate compositions (i.e., highly heterogeneous), and even oxygen isotope
> compositions
> and trace elements cannot always resolve them well. Even some of the most
> famous, best
> studied meteorites have been given various classifications in different parts of
> the literature
> (e.g., Tieschitz, Krymka, Bishunpur).
>
> If any meteorite has been called "LL/(L)3", I have no clue what this means.
>
>
> To: dgweir_at_earthlink.net
> koblitz_at_microfab.de
> Cc: meteorite-list_at_meteoritecentral.com
>
>
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Received on Fri 19 Mar 2004 04:27:12 PM PST