[meteorite-list] Mundrabilla IAB or IIICD ???????/

From: David Weir <dgweir_at_meteoritecentral.com>
Date: Mon Aug 23 21:31:18 2004
Message-ID: <412A9A0B.224D31D6_at_earthlink.net>

Hey Mike,

I'm not sure that my previous post gave enough of the story of the new
IAB-IIICD revision. Here is more info from my website that should
explain things better, taken from the 2002 GCA Wasson/Kallemeyn paper:

Current studies of the IAB iron group, utilizing the more definitive
element-Au diagrams, have resolved five well-defined subgroups in
addition to the large main group (Wasson and Kallemeyn, 2002). Subgroup
1 is the most closely related to the main group, while subgroups 2 and 3
correspond to the old groups IIIC and IIID. Subgroups 4 and 5 are more
distantly related to the main group. In addition to these, they resolved
two grouplets, five duos, and numerous IAB-related members. An outline
of the taxonomic system they propose is as follows:

main group (MG)
low-Au, low-Ni subgroup (sLL)
low-Au, medium-Ni subgroup (sLM); corresponding to the old group IIIC
low-Au, high-Ni subgroup (sLH); corresponding to the old group IIID
high-Au, low-Ni subgroup
high-Au, high-Ni subgroup
Udei Station grouplet, closely related to sLL
Pitts grouplet, intermediate between sLL and sLM
Algarrabo duo
Mundrabilla duo
Britstown duo
NWA 468 duo
Twin City duo
various single IAB-related irons


David
Received on Mon 23 Aug 2004 09:29:47 PM PDT