[meteorite-list] Chondrule craters

From: MARK BOSTICK <thebigcollector_at_meteoritecentral.com>
Date: Thu Apr 22 10:08:24 2004
Message-ID: <F4JEEPsbRKQCLNh4qpX00000ba9_at_hotmail.com>

Hello Bernd,

I was recently looking for the same (chondrule craters), and the chondrules
that look kinda like fans, showing how they were melted and resolidified. I
have a little over 50 meteoritic thin sections, the latest being a NWA047
Eucrite I got from the Comet Auction tonight (a low $35.00).

I would agree with your statement, Bernd. While I have not had the chance
to examine all my thins really well yet, I was using a bioscope before,
which was somewhat a hassle and got hot fast, and just recently purchased a
ACCU 3000 microscope. I have not found any chondrule craters, or at least
none that show really round chondrules, with really round indentions.
Chondrules in chondrules seem to be more common and ones that show evidence
of melting the most common but I am unsure of the later as weathering is
probley playing a factor. I will put looking at the chondrules on my things
to do list for when I get home.

Mark






>From: Bernd Pauli HD <bernd.pauli_at_lehrer.uni-karlsruhe.de>
>To: meteorite list <meteorite-list_at_meteoritecentral.com>,Jeff Rowell
><mrowell_at_rogers.com>
>Subject: [meteorite-list] Chondrule craters
>Date: Fri, 13 Sep 2002 21:47:31 +0200
>
>Hello All!
>
>On pages 230-231 of O.R. Norton's CEM (Cambridge Encyclopedia of
>Meteorites), the author describes chondrules with spherical indentations
>or "chondrule craters".
>
>There is also a color picture of such an indented radial pyroxene
>chondrule (Fig. 10.17, p. 231) in an Allende thin section. R. Norton
>writes on p. 230:
>
>'Surveying a type 3 or 4 ordinary chondrite thin section under
>low magnification * o f t e n * reveals chondrules with spherical
>indentations or "chondrule craters".'
>
>Maybe those listees who have microscopes and a thin section collection
>may wish to look at their chondritic thin sections and find out just how
>* f r e q u e n t * these indented chondrules are. So far I have "only"
>discovered two such critters in a Richfield thin section I purchased
>from AL two years ago. One of them is a 2 mm, slightly oval RP
>chondrule showing two such indentations arranged diametrically.
>
>Of course, I don't know how representative my thin section collection
>really is. So far there are 64 TS but I know there are others who have
>more than 100 thin sections. My latest addition is a Lost Creek (H3.8)
>thin section from Jeff Rowell - one of the most spectacular thin
>sections you may have come across. He's offering one on Ebay in case
>you are interested. The item number is: Item # 2100366205. Seldom
>have I seen such a multitude of diverse chondrules so close to
>each other.
>
>About 25 of my thin sections are type 3 or type 4 and I intend
>to search for such indented chondrules in all of them. But as
>I have already stated, I have found only one so far. Both indented
>chondrules in my Richfield thin section are RP chondrules and their
>chondrule craters are arranged diametrically. How frequent is such a
>* d i a m e t r i c a l * arrangement ?
>
>
>Cheers,
>
>Bernd
>
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Received on Sat 14 Sep 2002 01:23:00 AM PDT