[meteorite-list] Wild Horse, Colorado Meteorite Classification Note

[MARK BOSTICK]

Hello All,

Re: The Wild Horse Meteorite

http://www.meteoritearticles.com/files/wild_horse_crust_side_photo_1__35.2kb_.jpg

Wild Horse Meteorite, cut surface:
http://www.meteoritearticles.com/files/wild_horse_light_chondrules__37.8kb_.jpg

Wild Horse Meteorite Thin Section in light from my photo lights. Pure white 
light.
http://www.meteoritearticles.com/Wild_Horse_TS00a.jpg

     After cutting the Wild Horse meteorite, shown above, a little.  Me, and 
fellow Kansas Met. Soc. member Jerry Calvert, thought the H5 unusual for the 
meteorite, due to it's abundance of chondrules.  A type specimen and a 
(covered) thin section, was sent to Alan Rubin (UCLA) to get his thoughts.  
The following are Rubin's thoughts.

     "I looked at the thin section of Wild Horse today and, as you suspect, 
it is not an H5.  The chondrules are only a little recrystallized and there 
is low-Ca clinopyorxene in the chondrules.  This phase is abundant in 
type-3, present in type-4 and absent in type-5 and -6 chondrites.  From the 
degree of recrystallization and the abundance of low-Ca clinopyroxene, it 
looks like type-4 to me.
Because the section is not a doubly polished one for the probe, I cannot 
analyze the grains to make sure it is an H chondrite (or look at the 
abundance of metal to make the same determination), but the chondrule sizes 
seem to fit the H group.  So, my guess is that it is an H4."

Clear Skies,
Mark Bostick
www.meteoritearticles.com
www.kansasmeteoritesociety.com
www.imca.com