[meteorite-list] Chemical Groups of some Irons

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 10:02:31 2004
Message-ID: <3C98FDCF.221289DD_at_lehrer1.rz.uni-karlsruhe.de>

"Ing. Christian ANGER" wrote:

> Morasko IIICD - is it more related to IIIC or to IIID ?

Its bandwidth of 2.5 mm, its nickel content of 6.7 %, its gallium
content of 98.9 ppm (only Tabarz has a higher value), and its ger-
manium content of 496 ppm (only Burgavli has a higher value) would
make it a group I iron and this is how Buchwald classified it. But
it was reclassified as a IIICD iron by B.-G. CHOI et al. (1995) GCA
59, p. 593.
Why, I don't know because most IIICD irons have a narrower bandwidth,
a higher nickel content, lower gallium, germanium, and iridium values.

> Mundrabilla IIICD - is it more related to IIIC or to IIID ?

Its bandwidth of 0.6 mm would almost make it a IIIC, whereas its nickel
content is too low for groups IIIC and IIID, and again, the Ga, Ge, and
Ir values are too high although there are IIICDs with an iridium content
of 2.1. Buchwald classified it as anomalous due to its unique structure.

References:

BUCHWALD V.(1975) Iron Meteorites, Vol. 3, pp. 836-838.
WASSON J.T. (1974) Meteorites: Classification and Properties
(Springer-Verlag, Berlin-Heidelberg-New York, p. 36).


Best wishes,

Bernd
Received on Wed 20 Mar 2002 04:23:27 PM PST