[meteorite-list] Question Calcalong Creek Crust?

From: Randy Korotev <korotev_at_meteoritecentral.com>
Date: Thu, 29 Jan 2009 13:03:15 -0600
Message-ID: <200901291901.n0TJ1nh20536_at_levee.wustl.edu>

Adam:

I like it! When you cut it, send me 100-200 mg!

Several of those lunar meteorites that are regolith breccias have
vesicular fusion crusts.

http://meteorites.wustl.edu/lunar/stones/alha81005.htm
http://meteorites.wustl.edu/lunar/stones/que93069.htm
http://meteorites.wustl.edu/lunar/stones/que94281.htm
http://meteorites.wustl.edu/lunar/stones/yamato791197.htm
http://meteorites.wustl.edu/lunar/stones/calcalong.htm

I'm not aware of examples among the NWA and Dhofar meteorites, but
the fusion crusts on many of these have been destroyed, and a
vesicular crust is particularly vulnerable to destruction by wind ablation.

The lunar regolith is loaded with solar-wing implanted gases (which
penetrate only to a depth of few microns right at the moon-space
interface) because the fine grained stuff has lots of surface area,
it's gardened by micrometeorite impacts on the Moon so new stuff is
constantly exposed to the surface, the Moon is close to the sun
(compared to most asteroids), and the lunar regolith is thicker
because the Moon has more gravity than an asteroid. These gases are
released when the meteoroid is heated as it comes through the Earth's
atmosphere.

Some eucrites and howardites, I believe, are regolith breccias. I
don't know enough about these guys to know if any have vesicular
fusion crusts, but if they do, they're not likely to be as highly
vesicular as the those of lunar meteorites.

Randy Korotev







At 17:46 28-01-09 Wednesday, you wrote:
>Dear list Members,
>
>I was wondering if anybody had any close-up images of Calcalong
>Creek? A strange meteorite? with a brownish crust loaded with
>vesicles was found in some small Millbillillie Eucrites and sent to
>me some time ago. I know this is how Bob Haag found his lunar rock.
>I decided to take a chance on it and gave the finder a nominal fee.
>I came across it again while going through one of my safes and
>decided it was worth investigating some more. It only weighs 1.89
>grams so I do not want to cut it just yet. I saw the images on Randy
>Korotev's site and they look similar. I try not to judge too much on
>a single image.
>
>Here is an image of the crust on this object:
>http://themeteoritesite.com/Lunar-b.jpg
>
>Best Regards,
>
>Adam
Received on Thu 29 Jan 2009 02:03:15 PM PST