[meteorite-list] Zag classification, / - differences, pop quiz

David Weir dgweir at earthlink.net
Fri Nov 12 15:03:27 EST 2004


Hello Mike,

I have read a description of Zag that is a little more complex than the
interpretation of the H3-6 classification which you attribute to it. I
think you are correct in that the present accepted two-number system is
not adequate for some breccias. 

One source describes Zag as composed of four different lithologies -
both light and dark clasts (H5-6) [65 vol%] within a gray clastic matrix
(H3-4) [25 vol%], plus dark clasts [10 vol%] and impact-melt-rock clasts
[<1 vol%]. I'm not sure how such a petrographic mish-mash would be most
accurately represented, especially with only two numbers, but the proper
interpretation of H3-6 here would include petrographic types 4 and 5 as
well, I think. 

David



More information about the Meteorite-list mailing list