[meteorite-list] primitive Ureilite ?

From: j.divelbiss_at_att.net <j.divelbiss_at_meteoritecentral.com>
Date: Tue Sep 28 12:50:53 2004
Message-ID: <092820041650.22793.41599669000A1B150000590921603831169C9C070D040A90070BD206_at_att.net>

Hello all,

I was reading one of Adam's auctions this morning and noticed the word primitive attached to the word Ureilite and began to wonder what was the latest status on Ureilites being considered "primitive". I know the word is used with primitive materials like Acapulcoites and Lodranites because their age is suggested at the chondrite level of 4.5+ billion years.

I believe this reference for Ureilites infers the involvement of pre-solar or solar parts such as the diamonds versus a formation age of 4.5 billion years. Or maybe I'm wrong about that. At one time the diamonds were thought to be shock/pressure related, but recently Ureilites with low-shock values have been found that has scientists thinking that the diamonds came from some other source.

What is considered the formation age of Ureilites? And does that age in itself make them primitive, or does the parts/pieces make them considered primitive?

Curious,

John/JD
Received on Tue 28 Sep 2004 12:50:49 PM PDT