[meteorite-list] Cosmic Microscopy and Primary Colors

From: Martin Horejsi <martinh_at_meteoritecentral.com>
Date: Thu Apr 22 09:48:13 2004
Message-ID: <B7FEC09A.2A4%martinh_at_isu.edu>

A few years ago, I took a collection of meteorite thin sections to our
geology department to use their petrologic microscope and camera. A friend
who is experienced with that kind of work and I played a game. I would place
a thin section in the scope, and then he, without knowing specifically what
he was looking at, would describe what he saw and speculate on the processes
that took place to create the rock from which the thin section came from.

It was amazing to listen to him put together the pieces of information into
the same story I usually read in books about the origins of different kinds
of meteorites. He nailed eucrites, various types of chondrites (Murchison
was especially interesting), a pallisite, and amesosiderite. When I placed
an aubrite (Cumberland Falls) under the scope, he described it chemically,
then deduced that it was an enstitite-rich something or other, but he did
not know how it would have formed. Again, what is usually read in the texts.

Now I'm sure O.R. Norton is thinking Duh!, but for me it was a rather
enlightening experience to have a professional petrologist "read" the
contents of a meteorite through a thin section, and describe what it
actually is, not just give the specimen name or classification. In fact, he
did not know all the meteorite classifications so he would just list the
primary minerals and formation history of those minerals.

Cheers,

Martin
Received on Fri 26 Oct 2001 09:26:19 AM PDT