[meteorite-list] R Chondrites and Magnetism

From: bernd.pauli_at_paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: Tue May 31 10:09:18 2005
Message-ID: <DIIE.0000003B000038B7_at_paulinet.de>

Hi Tom and List,

Here is an excerpt from the "good old" RFS:

NORTON O.R. (1998) Rocks From Space, pp. 190-191:

and iron-nickel metal is nearly absent. Most of the metal is in the sulfides
pyrrhotite (FeS) and pentlandite [(Fe,Ni9)S8] or combined with olivine. The
pyrrhotite is magnetic, giving the meteorites a *w e a k m a g n e t i c
a t t r a c t i o n*. The fayalite content averages about Fa39, which is the
highest iron-bearing olivine content of any of the chondrites and is chemically
the most distinctive characteristic. Rumurutiites have the highest iron oxidation
of the chondrite class.

see also:

BLAND P. et al. (1992a) A unique type 4 chondrite from the
Sahara - Acfer 217 (abs. Meteoritics 27, 1992, 204-205):

"Acfer 217 is a chondrite that is exceptionally poor in metal and
sulfide and rich in oxidised Fe. It appears to be unique ..."

and also:

SCHULZE H. et al. (1994) Mineralogy and chemistry of Rumuruti:
The first meteorite fall of the new R chondrite group
(Meteoritics 29-2, 1994, pp. 275-286):

"Meteorites of this new group can be characterized as
 oxidized, olivine-rich, metal-poor chondrites, ..."

And, as Buckleboo Martin wrote: No metal or hardly any metal
automatically implies no magnetism or extremely weak magnetism.


Best wishes,

Bernd
Received on Tue 31 May 2005 10:09:16 AM PDT