[meteorite-list] NWA 2058

[Adam Hupe]

Dear List,

I hope the following partial description I wrote helps to clarify my
statements in regards to NWA 2058:

NWA 2058, an H (Pseudotachylite), S6 plus, W2 chondrite found in Northwest
Africa in 2001.  This unique meteorite cannot be subclassed because of
extreme mylonitization.  Mylonitization is fusion of crushed rock under high
temperature by frictional heating.  In other words, this meteorite was
formed by a hypervelocity impact on the surface of an asteroid and cooled
within milliseconds as it was ejected out into space.  During the impact
event it was crushed and sheared simultaneously creating subparallel veins
in the direction of the material flow connecting the elongated metal-sulfide
nodules, talk about odd!  Relic grains show evidence of high strain rates,
partially granulated clasts with undulatory extinction, in contrast to shock
features.  The matrix consists mostly of recrystallized olivine. The round
objects are not chondrules but are impact melted and quenched metal sulfide.

Take Care,

------------------------------------
Adam Hupe
The Hupe Collection
Team LunarRock
IMCA 2185
raremeteorites at comcast.net