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: [EMAIL PROTECTED] > [EMAIL PROTECTED] > Cc: [EMAIL PROTECTED] > > > ______________________________________________ > Meteorite-list mailing list > [EMAIL PROTECTED] > http://www.pairlist.net/mailman/listinfo/meteorite-list ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
