[meteorite-list] Fractional Classification of LL3's

From: jngrossman at gmail.com <jngrossman_at_meteoritecentral.com>
Date: Sat, 30 Nov 2019 21:05:04 -0500
Message-ID: <012801d5a7eb$bff1ddb0$3fd59910$_at_gmail.com>

As it turns out, it is very easy to see if an OC is type 3.05-3.15. The exsolution of chromite from olivine in type II porphyritic chondrules can be seen in an optical microscope, with the aperture stopped down. It looks like this: https://www.lpi.usra.edu/meteor/get_original_photo.php?recno=5674513. See the little wormy lines? Subdividing these into 3.05, 3.10, and 3.15 does take some work, but you?d be safe classifying them as type 3.1 if this effect is visible.

 

If a meteorite has black opaque matrix, razor sharp chondrules, and you CAN?T see exsolution in any olivines, the meteorite bears closer inspection to see if it is extra special.

 

Jeff

 

From: Meteorite-list <meteorite-list-bounces at meteoritecentral.com> On Behalf Of Graham Ensor via Meteorite-list
Sent: Monday, November 11, 2019 2:38 AM
To: Kevin Kichinka <marsrox at gmail.com>
Cc: meteorite list <meteorite-list at meteoritecentral.com>
Subject: Re: [meteorite-list] Fractional Classification of LL3's

 

Hi Kevin,

 

As far as I can make out, talking with other researchers, then it can/will be done but takes extra time and work and thus many just get given the 3 designation rather than do all that work to divide it up even more...although if one is suspected as a 3.00 then I imagine it is worth it or if the presenter of the specimen pays for the time and effort to do the work.

 

Graham

 

On Mon, Nov 11, 2019 at 12:57 AM Kevin Kichinka via Meteorite-list <meteorite-list at meteoritecentral.com <mailto:meteorite-list at meteoritecentral.com> > wrote:

Team Meteorite:

 

A couple of years ago it seemed that researchers were no longer going to sub-divide LL3 mets to classifications like 'LL3.05' or 'LL3.10', or I suppose the most primitive one of LL3.0'.

 

Can someone clarify this issue for me?

 

And regards to Zsolt Kereszty while referencing his acquisition of NWA12692 LL3.00

 

"Here is the MetBull page of the NWA12692 LL3.00 meteorite:"

https://www.lpi.usra.edu/meteor/metbull.php?code=70116

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Received on Sat 30 Nov 2019 09:05:04 PM PST