[meteorite-list] Chondrule craters

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 10:08:24 2004
Message-ID: <3D8240D3.D4CB599F_at_lehrer.uni-karlsruhe.de>

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
Received on Fri 13 Sep 2002 03:47:31 PM PDT