[meteorite-list] Udei Station vs. NWA 4024 winonaite types

[Jeff Kuyken]

G'day Mike,

I asked this very same question about a year ago and got some very good 
replies. Here are some of them:

http://six.pairlist.net/pipermail/meteorite-list/2010-March/062685.html
http://six.pairlist.net/pipermail/meteorite-list/2010-March/062688.html
http://six.pairlist.net/pipermail/meteorite-list/2010-March/062729.html
http://six.pairlist.net/pipermail/meteorite-list/2010-March/062736.html

Bernd summarised with the following:

"It is likely that the winonaites cooled faster than the silicates in IAB 
irons,
which may have been more deeply buried. This is supported by the metallo-
graphic cooling rates of Winona, 200°C/Myr, and IAB irons, 10-50°C/Myr.

So, maybe these metallographic cooling rates can help make a clear(er)
distinction between the two: Silicated IAB's and winonaites."

Cheers,
Jeff Kuyken
Meteorites Australia
www.meteorites.com.au
Vice President - I.M.C.A. Inc.
www.imca.cc


----- Original Message ----- 
From: "tett" <tett at rogers.com>
To: <meteorite-list at meteoritecentral.com>
Sent: Saturday, February 26, 2011 10:39 PM
Subject: [meteorite-list] Udei Station vs. NWA4024 winonaite types


> List,
>
> When stumbling across an ad for NWA4024 I saw pictures of the meteorite 
> and immediately thought how similar it looks to Udei Station.  Comparing 
> the pics of NWA4024 and my slices of Udei Station reveal very similar 
> compositions.  However, NWA4024 is classiifed as a winonite where as Udei 
> Station is classified as an IAB iron.
>
> Further research shows that it is likely Udei Station and other IAB irons 
> along with Winonites come from the same parent body.   My question is, 
> what is the dividing line between Winonites and IAB's?  How does one 
> decide which group the meteorite should fall?  Is it %Fe?
>
> Thanks for any help and
>
> Cheers!
>
> Mike Tettenborn
> ______________________________________________
> Visit the Archives at 
> http://www.meteoritecentral.com/mailing-list-archives.html
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list
>
>