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

From: David Weir <dgweir_at_meteoritecentral.com>
Date: Fri Nov 12 15:03:47 2004
Message-ID: <4195170F.85573CF8_at_earthlink.net>

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
Received on Fri 12 Nov 2004 03:03:27 PM PST