[meteorite-list] Chassigny Chondrules Repost

From: bernd.pauli_at_paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 10:21:09 2004
Message-ID: <DIIE.0000005D00000D64_at_paulinet.de>

Mark inquired:

> Does anyone know what the current thinking on the 'Chassigny
> Chondrules' is? (as to what they actually are or how they formed?)
 
I found this, but can anyone point me in the direction of any further information?
 
http://www.geocities.com/~dweir/chassig1.htm
 
 Hello Mark and List,

At 19:11 12/04/00 +0200, you wrote:

FERNLEA4_at_aol.com schrieb:

The 1985 Blue Book lists it and surprisingly states that "it contains chondrules".
How can this be? I can't find any references to Chassigny chondrules after wading
through a mountain of abstracts. Confused, Rob.

Hello Confused Rob and All!

Both the third and fourth editions of the Meteorite Catalogue state that Chassigny
contains chondrules. I think this is a misinterpretation of a paper by Mason B. et al.
(1975) The composition of the Chassigny meteorite (Meteoritics 11, 1975, pp. 21-27).
The authors suggested that Chassigny is an olivine-rich cumulate derived from a
c h o n d r i t e - like magma.

But in his book "Meteorites" published in 1962, Brian Mason clearly states on p. 111
that it differs from the "olivine-pigeonite chondrites" in the a b s e n c e of chondrules.
Now, where does this misconception about chondrules stem from? Varela M.E. et al.
found pure glass inclusions (< 20 =B5m in diameter) in Chassigny that have a "nearly
circular disk shape and generally occur in clusters." They also found " multiphase
inclusions (> 20 =B5m in diameter)" that have "a rounded or euhedral shape and occur
generally isolated". Perhaps these circular disks were misinterpreted as chondrules
in the early sixties. My two cents! :-) Best regards, Bernd

Best wishes,

Bernd

To: markf_at_ssl.gb.com
Cc: meteorite-list_at_meteoritecentral.com
Received on Mon 28 Jul 2003 11:09:11 AM PDT