[meteorite-list] ALBION: Rocks from Space Picture of the Day -September 7, 2009

From: bernd.pauli at paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: 07 Sep 2009 14:25:45 UT
Message-ID: <DIIE.0000006700003FE7_at_paulinet.de>

Hello Jeff, Greg, and List,

Here is what I can contribute from the two references cited. Enjoy!

Cheers,

Bernd


Jeff wonders:

Well that is one very cool looking feature indeed! And that's a good question
Greg. But the thing that gets me is that the Widmanst?tten pattern (1) is basically
complete. And what is that grayish material? It looks a little like troilite or
cohenite (2). And then there are the small bright silver blobs (3) inside that material.
Schreibersite?

(1) U.B. Marvin: Albion a IVA fine octahedrite, is unique in having vugs
scattered throughout the otherwise orderly Widmanst?tten structure...

(2) U.B. Marvin: The spheroidal masses consist mainly of irregular kamacite
grains 1-35 mm across, containing 2-3.5 wt% Ni...thin, branching films of troilite...

(3) U.B. Marvin: ... a few rounded segregations of Ni-rich tetrataenite with 55.6 wt% Ni


Greg would like to know:

Do those look like 'melted' matrix droplets forming while this meteorite went
through super heating at some point and created the gaseous voids (vugs)?


M.E. Petaev: The crystalline linings in the vugs of the Albion iron, described in our companion
paper, provide clear evidence of deposition from a fluid phase - most likely a vapor - that passed
through the mass of iron at a late stage in its history.

References:

Marvin U.B. et al. (1996) Drusy vugs in the Albion iron meteorite:
Mineralogy and textures (abs. Meteoritics 31-4, 1996, A083).

Petaev M.E. et al. (1996) Drusy vugs in the Albion iron meteorite:
Early speculations on the origin (abs. Meteoritics 31-4, 1996, A107).
Received on Mon 07 Sep 2009 10:25:45 AM PDT