[meteorite-list] Did All CI's Originate on Mars?

[Alan Rubin]

Several groups of meteorites have similar O isotopes, for example, the 
Earth, Moon, EH chondrites, EL chondrites, aubrites all have the same 
O-isotopic compositions.  No one would say that they are all derived from 
the same parent body.  All that means is that the preponderance of material 
is from the same O-isotopic reservoir.  One does not expect chondritic 
meteorites to be derived from a differentiated body.  The igneous processes 
involved in differentiation fractionate the chemical composition of the 
constitutent rocks in various ways, making them distinctly non-chondritic. 
This is particularly true of REE.  The CI chondrites have many similarities 
to CMs, indicating that they formed by a similar process, presumably on a 
similar asteroid.  These textural similarities include the olivine Fa-CaO 
distributions which are similar to those in CM chondrules and CM isolated 
olivine grains.  There are also vary rare chondrule fragments, CAI fragments 
and even one CAI in CI chondrites, indicating that they are real chondrites 
in terms of texture as well as composition.  There is no good reason to 
believe that they are from Mars.


Alan Rubin
Institute of Geophysics and Planetary Physics
University of California
3845 Slichter Hall
603 Charles Young Dr. E
Los Angeles, CA  90095-1567
phone: 310-825-3202
e-mail: aerubin at ucla.edu
website: http://cosmochemists.igpp.ucla.edu/Rubin.html


----- Original Message ----- 
From: "Kevin Kichinka" <marsrox at gmail.com>
To: <meteorite-list at meteoritecentral.com>
Sent: Saturday, March 15, 2014 4:51 PM
Subject: [meteorite-list] Did All CI's Originate on Mars?


> Team Meteorite:
>
> David Weir just shared this paper with me. He exuded shock and awe. I
> read it, and although not doing further data follow-up, I am sitting
> here with the sun setting in the mango orchard, stunned.
>
> Can we get some other discussion about this?
>
> http://www.hou.usra.edu/meetings/lpsc2014/pdf/1143.pdf
>
> Kevin Kichinka
> MARSROX at gmail.com
> Rio del Oro, Santa Ana, Costa Rica
> "The Art of Collecting Meteorites' available as an eBook on
> Amazon/Barnes and Noble
> "The Global Meteorite Price Report - 2015" available in December, 2014
> ______________________________________________
>
> Visit the Archives at http://www.meteorite-list-archives.com
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list