[meteorite-list] Chondrule Formation vs Chondrule Conglomerate

From: Jeff Kuyken <info_at_meteoritecentral.com>
Date: Fri May 13 22:10:39 2005
Message-ID: <001801c5582a$1c38ea90$57598b90_at_mandin4f89ypwu>

G'day List,

I was just reading through a section of 'Planetary Materials - Reviews in
Mineralogy, Volume 36' regarding Chondrules when one particular sentence
stuck out. It says:

"A transient heating event melted the dustballs, and they were subsequently
cooled, initially at rates around hundreds of degrees per hour or faster,
before accreting into their chondritic parent bodies (e.g. Wasson 1993,
Hewins 1996)."

So, taking this at face value then how does one account for the "Chondrule
Conglomerates" which have started popping up? E.g.
http://www.meteorites.com.au/features/nwa2892.html

I find it intriguing that if the chondrules were cooling at such a rapid
rate, then these meteorites would need to have accreted faster or at least
as fast. My 'very basic' understanding also would lead me to believe that if
these are Type-3 chondrites, then it rules out later metamorphism? (E.g.
Remelting of chondritic parent body.)

Could these chondritic parent bodies have accreted this fast?

Thoughts?

Cheers,

Jeff
Received on Fri 13 May 2005 10:10:29 PM PDT