[meteorite-list] Regmaglypts

[Steve Dunklee]

so you are meaning bubbles of olivine and metal , or chondrules which are bubbles of solid material, not bubbles of gasses like most people think bubbles are? a good example might be an armored chondrule where you have a heavier ring of metal surrounding  silicate lighter material on the inside. instead of a thin layer of soap with gasses on the inside? at temperatures high enough to make the silicates a gas and metal a liquid, the cooling of the metallic bubbles creates chondrules. the same way trapped gasses in ice create spherical bubbles of gasses. you have  metals or other material with a higher melting point acting as the thin soap skin of the bubble. and lighter materials cooling from a gas to a solid? or with chondrites the surface tension of the molten material creates spheres or chondrules which could also be described as bubbles. slag would be a good example! as the oxide  metal and sulphides cool it creates lots of vesicles of spherical
 gasses. in space with no gasses the vesicles would become a spherical solid upon cooling.
 take this with a grain of salt i am only guessing here!
Steve Dunklee

--- On Wed, 1/27/10, abudka at nycap.rr.com <abudka at nycap.rr.com> wrote:

> From: abudka at nycap.rr.com <abudka at nycap.rr.com>
> Subject: [meteorite-list] Regmaglypts
> To: meteorite-list at meteoritecentral.com
> Date: Wednesday, January 27, 2010, 12:18 PM
> My Response Jan 27, 2010
> 
> Subject: Re: [meteorite-list] Regmaglypts 
> 
> Jason and All,
> 
> 1.  My reference to “bubbles” is to morphology,
> NOT voids.  Another meteoritic example of “bubble
> morphology effects” is pallasitic olivines such as
> Springwater and Imilac.
> 
> A thought experiment: Once again, envision a melt mass of
> olivine and nickel-iron solidifying under microgravity
> conditions – surface energy dominates gravity.  
> 
> On cooling, olivine begins to solidify before nickel-iron.
> However, since olivine and iron-nickel share a range of
> temperatures where both are still at least partially liquid
> (mushy stage), as cooling continues, still-plastic olivines
> can be surrounded by and sometimes infiltrated and pushed
> apart by liquid nickel-iron.  
> 
> Cut and polished sections of Springwater and Imilac reveal
> this as a relatively complex process.  Observe 120
> angles between some olivines, evidence of a system governed
> by surface energy.  Some olivine boundaries are
> straight (interior polyhedral shapes); some are circular (a
> sphere minimizes surface area to volume ratio); some
> straight and curved (perhaps on the outer surface of the
> olivine mass). See my "Stepping Back in Time" article in
> Meteorite magazine Nov. 2003, Vol. 9 No. 4, pp. 21-22 or see
> it in the publications list on my website at http://meteormetals.com
> 
> 2.  There is NO WAY that the thermal history of a
> metal can be calculated in reverse, despite hundreds of
> papers in the meteoritics literature since the original
> paper of Osmond and Cartaud in 1904 and the more recent,
> detailed papers on “metallographic cooling rates!” 
> That is more than 100 years of circular reasoning! 
> Industrial metallurgists would be a lot happier if this
> backward calculation were possible.  It is NOT! 
> 
> 3.  Speaking of industrial metallurgists, do another
> experiment: show a cut section of any nickel-iron or stony
> iron meteorite to a modern INDUSTRIAL metallurgist. 
> Ask him or her to describe the microstructure, without you
> giving them any “meteorite words” or concepts. 
> Then, Listen!  Next, give that person one of the
> metallic meteorite papers in the meteoritics literature
> (other than mine) and see if that person can even understand
> the language and concepts.  Meteoritics metallurgy has
> sealed itself inside an old language, not accessible to
> today’s busy, industrial metallurgists.  To quote one
> of my industrial metallurgist friends who is a casting
> expert and who has become a meteorite collector, "meteorite
> metallurgy is in the Stone Age."
> 
> We need a NEW METALLURGY for meteorites!  Imagine what
> we could learn!
> 
> Phyllis Budka
> http://meteormetals.com/
> 
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