[meteorite-list] No nickel-free iron meteorites

From: Matson, Robert D. <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Fri, 26 Mar 2010 14:31:55 -0700
Message-ID: <7C640E28081AEE4B952F008D1E913F17030B5753_at_0461-its-exmb04.us.saic.com>

Hi Carl,

Alan wrote:

> "Please note that volumetrically, the amount of low-Ni metallic Fe is
> trivial, far less than 0.1% of a typical chondrite."

You replied:

> ".1% is a relative term. Earth may be only a fraction of the size of
> Artares [Antares] but, it is still a pretty big rock."

I don't think you're quite absorbing what Dr. Rubin is saying. There is
no
natural solar system mechanism that can separate iron from nickel in
macroscopic quantities. So if you find a lump of iron on earth that
doesn't
have nickel in it, it originated here. It is not a question of there
being
room for reasonable doubt. It simply cannot happen. The physics of
nucleosynthesis, cosmochemistry, and entropy do not allow it.

Best,
Rob
Received on Fri 26 Mar 2010 05:31:55 PM PDT