Thank you all for your comments!
I am not sure either that ablation would be a huge factor in why we are
not finding olivine meteorites. The mean melting is about 3100 degrees
F (Fo = ~3450F, Fs =~2752), I think. I suppose, if I look at the
earth's mantle, olivine is a primary mineral but even then, I do not
find large chunks just laying around waiting to be found. My thinking
is that if it is such a primary mineral, we should see more, not knowing
the factors that completely effect it.
Jim
On 1/14/2014 10:25 PM, Alan Rubin wrote:
Iron meteorites tend to break up in the atmosphere at lower depths
than stony meteorites, so I suppose that pallasites would also be
better able to survive transit through the Earth's atmosphere than
dunites. But I am guessing that very few dunites ever make it to the
top of the Earth's atmosphere to begin with.
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: aeru...@ucla.edu
website: http://cosmochemists.igpp.ucla.edu/Rubin.html
----- Original Message ----- From: <pshu...@messengersfromthecosmos.com>
To: "Alan Rubin" <aeru...@ucla.edu>; "Jim Wooddell"
<jim.woodd...@suddenlink.net>; <meteorite-list@meteoritecentral.com>
Sent: Tuesday, January 14, 2014 5:27 PM
Subject: RE: [meteorite-list] Near pure Olivine Meteorite
Would they also melt or more correctly ablate off material faster and
more completely
upon entering the earth's atmosphere?
Pete
-------- Original Message --------
Subject: Re: [meteorite-list] Near pure Olivine Meteorite
From: "Alan Rubin" <aeru...@ucla.edu>
Date: Tue, January 14, 2014 6:54 pm
To: "Jim Wooddell" <jim.woodd...@suddenlink.net>,
<meteorite-list@meteoritecentral.com>
The question of the dearth of olivine meteorites (asteroidal dunites)
has
been around for a very long time. Most folks have ascribed this
paucity as
being due to the brittle nature of olivine meteorites relative to
pallasites. Pallasites have relatively long cosmic-ray-exposure ages
indicating that they can survive the rigors of interplanetary space
for a
rather long while. Eucrites have much shorter CRE ages on average.
This
suggests that if asteroidal dunites are from deep in the mantle, they
would
be in space about as long as the pallasites and not survive because
they are
no tougher than eucrites.
Alan
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: aeru...@ucla.edu
website: http://cosmochemists.igpp.ucla.edu/Rubin.html
----- Original Message ----- From: "Jim Wooddell"
<jim.woodd...@suddenlink.net>
To: <meteorite-list@meteoritecentral.com>
Sent: Tuesday, January 14, 2014 4:05 PM
Subject: [meteorite-list] Near pure Olivine Meteorite
> ______________________________________________ -----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4259 / Virus Database: 3658/7003 - Release Date: 01/14/14
--
Jim Wooddell
jim.woodd...@suddenlink.net
http://pages.suddenlink.net/chondrule/
______________________________________________
Visit the Archives at http://www.meteorite-list-archives.com
Meteorite-list mailing list
Meteorite-list@meteoritecentral.com
http://six.pairlist.net/mailman/listinfo/meteorite-list
