[meteorite-list] Micrograph gallery post Lunar crust and Lodranite

[Starsinthedirt at aol.com]

Thanks Carl,  I think you are right but I  have grown shy of making large 
sweeping claims.  When ever I do, I just  learn what I don't know.

I would say that in some instances, melted  material from entry remains on 
the meteorite.  But as it has been long  accepted that the trailing edge of 
an oriented stone can accrete some material,  this may not be a significant 
observation.  If I found this in all fresh  crust, then I would be onto some 
thing.

A couple years ago I wrote a  Micro Vision article for Meteorite Times 
Magazine called Crystals in the  Crust"  It was centered on NWA 2371 H4.  I 
chose this meteorite  because of the very cool inclusion on the edge of my 
sample.  Sort of  crystals in the crystals!  The image clarity was not as good 
back then and  the focus seemed to be on the inclusion structure and not the  
dentrites.

Perhaps I should make an update to the NWA 2371 Gallery  post.  For now, 
any one who wants to see a few of those "New" images, just  email me.  I will 
embed (Reduced!) several images and try to send one full  size as an 
attachment.  Due to file size only one full size file can be  sent at a time and 
even at that, some of the ISP's will not allow a file that  big.

Thanks for the interest.

Tom Phillips   

In  a message dated 5/27/2010 8:32:44 A.M. Mountain Daylight Time, 
cdtucson at cox.net  writes:
Tom,
On a serious note with regard to the dendrites found in Lunar  fusion 
crusts.
This is not only amazing to look at but, you may have stumbled  upon 
something of significant importance here.
It has always been a chore to  determine whether what appears to be fusion 
crust is actual fusion crust or  perhaps something else.
The choices include Fusion crust, desert varnish and  weathering rind to 
name a few. 
In iron meteorites this dendritic texture  is  proof of melting. Many irons 
display this texture throughout the entire  meteorite again as proof that 
it was once molten. 
Your discovery of this  texture found only on the exterior of this lunar 
meteorite seems to be  sufficient proof that only the exterior of this Lunar 
meteorite actually  melted?  As you point out that this texture is only seen 
in the crustal  area of the meteorite.
Although this may be an anomaly and may not occur in  all fusion crust. One 
thing may be certain. If it does occur there maybe melting  going on. This 
would be far different than what occurs in the forming of a  desert varnish 
or a weathering rind.
So, in summary. It seems to me this  could be a significant aid to our 
Scientific community in initial determination  and analysis of what is going on 
with respect to fusion crusts. And ultimately  add to the proof that the 
rock was once in space. What else would cause only the  exterior portion of a 
rock to melt? Fusion crust is key in recognizing  meteorites and this new 
discovery may have just made recognition a whole lot  easier. 
Perhaps all crusts could be checked at this great magnification to  see if 
they too have this texture.
Even if this texture is not always present  in crusts at least when it is,  
there would be no doubt about how it formed  and what it is.
This could save valuable microprobe time as it does not cost  much money to 
look at the crust at a high magnification. If it has this texture  the 
Scientist knows he needs to continue to study. 
Back in the day. I do  know that David Kring would always require that 
polished thin sections would  always include the fusion crust area for 
observation. So, is this a well kept  secret and scientists already look for this? 
It would be great to see how  often this texture actually does occur in 
crusts of stony meteorites. I know I  have thin sections with crust but, no 
high power microscope. Tom, perhaps you  could lead the charge on this. Maybe 
start a service to check crusts prior to  sending them off to Scientists. 
This could weed out at least some of the  junk? 
Great job Tom.
Carl


--
Carl or Debbie  Esparza
Meteoritemax


---- Starsinthedirt at aol.com wrote: 
>  Hi List,  Paul (Meteorite Times) has worked  his magic and set up two  
new 
> articles on my meteorite micrograph  gallery.
> 
>  The first is NWA 6075 Lodranite found  at
> 
>  http://www.meteorite.com/meteorite-gallery/articles/nwa-6075/
> 
>  
> The  second is a set of very high magnification images of a Lunar  crust 
on 
> NWA  2977.  There really are crystals in this  crust!   It can be found  
at  
> 
>  http://www.meteorite.com/meteorite-gallery/articles/nwa-2977/
> 
>  I  previously posted some of these shots on Face Book and some of you 
may  
> have seen  them but many more have been posted in my  gallery.
> 
> Please take a look and  comments are  appreciated!
> 
> Tom Phillips  
> 
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