[meteorite-list] Harrison Brown / Abundance of Gold, B.W

From: MexicoDoug <mexicodoug_at_meteoritecentral.com>
Date: Tue, 4 Oct 2011 03:11:39 -0400 (EDT)
Message-ID: <8CE507BFEE1A159-2300-6F49A_at_webmail-d140.sysops.aol.com>

Iron meteorite classification: in the beginning...

(Repost when I said stay tuned, for some reason it didn't go through.
It was :)

This is a good reason to pay respects to Harrison Brown, who was an
American meteoriticist born in 1917; worked with the nuclear physicists
throughout the War and is the pioneer at the University of Chicago
along with the Anders crowd, that gift-wrapped for Leonard (and via
osmosis, Wasson) some of their most interesting fields of study.

Brown, with his grad student had no top secret responsibilities left
after the war and turned to merge his love of chemistry, work with
nuclear chemistry to ffirst apply neutron analysis to the
classification of iron meteorites and broke the ground for the
classification scheme we have today. Way back in 1949, he discussed
his results at UCLA and it caught on with the rest of the
meteoriticists.

He analyzed 45 irons of all types and found the highest gold
concentration was:

Bear Creek (Colorado, USA)
Gold content: 2.5 ug/g (yes, that's micrograms per gram i.e., ppm)
(Doug note: well below the 1490 ug/g reported in the Bulletin of NWA
6932)

So Mike - that's an oldie but goodie and addresses your question of
gold content and pretty much says it?s an error in the Bulletin you
were basing this on, without a reasonable doubt.

  Be fun to compare the values with modern analytical techniques.

Here's the reference:

http://articles.adsabs.harvard.edu//full/1949PA.....57..398L/0000399.000.html

Kindest wishes
Doug
PS(edit later for the benefit of Yinan) the lowest gold concentration
of the 45:
0.094 ug/g (ppm) vs. highest: 2.5 ug/g, so the endpoints of the range
are by a factor of 25
Received on Tue 04 Oct 2011 03:11:39 AM PDT