Fwd: Re: [meteorite-list] Olivine with Spinel Structure in Meteorites (some additional info)(sorry if some of you get this twice)

From: Steven Singletary <jumper_at_meteoritecentral.com>
Date: Thu Apr 22 09:46:22 2004
Message-ID: <200105071220.IAA23980_at_melbourne-city-street.mit.edu>

>Date: Sun, 06 May 2001 11:43:01 -0400
>To: Meteorite-list_at_meteoritecentral.com
>From: Steven Singletary <jumper_at_mit.edu>
>Subject: Re: [meteorite-list] Olivine with Spinel Structure in Meteorites
(some additional info)
>Just to add some additional information (sorry to come into this late)
>Perovskite is a pseudocubic mineral (CaTiO3) and is not technically a
spinel nor close in chemical make up. However they are often talked about
in the same breath (with olivine and the like) when talking of deep mantle
>The change in crystal structure in olivine is thought to occur in the
transistion zone of the earth (anywhere from 600 to 700 km down) where
olivine goes first to beta- and then to gamma- olivine, termed Wadsleyite
and Ringwoodite. Neither of which we have found on the earth except in
meteorites and the lab. These two have the same chemical composition as
olivine but different structure - the spinel structure.
>Again sorry to come into this late, what was the original inquiry? I like
the science discussions on this list but they usually get drowned out by
the business end of it all and I usually just hit the delete key......:(
>At 08:17 AM 5/6/01 -0700, you wrote:
>>Hello Bernd and Elton:
>>You should include the term "perovskite" in your
>>search routine. It would probably result in an
>>additional list of papers directly related to this
>>physical structure transition in olivine.
>>Spinel can be found in many types of meteorites, but
>>the spinel-like crystal structure of olivine is not
>>that common.
>>Hope this helps, as well.
>>Bob V.
>>--- Bernd Pauli HD
>><bernd.pauli_at_lehrer1.rz.uni-karlsruhe.de> wrote:
>>> Elton wrote:
>>> > Is anyone aware of any research where the olivine
>>> > in meteorites was found to exist in the spinel
>>> > crystal structure?
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Steven Singletary
Dept. Earth, Atmospheric, and Planetary Sciences
Cambridge, Ma., 02139

Blue Skies!!
Received on Mon 07 May 2001 08:24:21 AM PDT

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