[meteorite-list] Timing is Everything

From: Gerald Flaherty <grf2_at_meteoritecentral.com>
Date: Wed Apr 20 17:46:51 2005
Message-ID: <014501c545f2$6ca43470$6401a8c0_at_Dell>

Thanks Kevin, it helps clarify[slightly] an issue that's screaming for
investigation. Jerry Flaherty
----- Original Message -----
From: <MARSROX_at_aol.com>
To: <meteorite-list_at_meteoritecentral.com>
Sent: Wednesday, April 20, 2005 4:52 PM
Subject: [meteorite-list] Timing is Everything


> Thanks to Mike Jensen for the heads-up on the paper newly published by
> Dr.
> Jeff Grossman and Adrian Brearley refining the measurement of
> classification
> for chondrites.
>
> In the last couple of days, including today, I've been working on a
> feature
> for "Meteorite" magazine that includes discussions I had with Dr.
> Brigitte
> Zanda, the curator of the NHM met collection in Paris about her research
> in
> chondrule formation. We talked about her discovery of chondrules in a
> plastic
> state during formation in Semarkona LL3.0, perhaps the most primitive
> chondrite.
>
> The most obvious point here is that chondrules were observed in formation
> that are not spheres. It's an exciting discovery in today's most
> happenin'
> meteorite research area - the origins of chondrules. You can read more of
> this
> discussion in "Meteorite" come August.
>
> One side area of interest with all this, is that petrology is now
> determined
> by using "thermaluminesence." This technique is a bit more sophisticated
> than when one looks at a slice of something and expertly guesses, "Oh,
> that
> looks like a L5."
>
> A discussion has risen about thermaluminesence measuring because it's
> possible that terrestrial weathering can alter the outcome of a
> pre-terrestrial
> event, changing what observers think is a most primitive 3.0 to a 3.2 or
> 3.4.
>
> On my first quick read of this (I have a meeting in 30 minutes), Jeff and
> Adrian's paper seems to propose extremely accurate measuring of petrology
> in
> type 1 chondrules by combining electron microscopy and
> cathodoluminescence in
> their observations. The resultant measurements would be several times
> more
> accurate than present thermaluminesence techniques, i.e. resulting in
> petrology's of 3.05, 3.10, etc., instead of just 3.0 or 3.2.
>
> However, I'm assuming that cathodoluminescence (can't type that too many
> times without misspelling) is different from thermaluminesence (and I'm
> sure
> someone will soon let me know if it isn't - smiley face here). But this
> is great
> work and seems to me to be exciting news.
>
> Kevin Kichinka
>
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Received on Wed 20 Apr 2005 05:46:34 PM PDT