[meteorite-list] ALH 84001 Before the Martian Debate

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 09:44:11 2004
Message-ID: <3B1BC829.8131BE21_at_lehrer1.rz.uni-karlsruhe.de>

Hello All!

Do you remember what ALH 84001 was classified as before
the scientific community "realized" it is presumably of Martian
origin, before the debate that is still raging on whether or
not it contains fossil life, split scientists in two opposing
groups?

It was classified as a ==> d i o g e n i t e <==

But meteoriticists soon discovered certain petrologic features
indicating it was not a diogenite - among these were:

- it contains iron sulfide and FeS* has not been reported from
  diogenites
- the composition of maskelynite falls within the range of other SNC's
- in thin section: patchy extinction of coarse-grained orthopyroxene

* pyrite not troilite!

P.H. Warren (1994) A carbonate-rich piece of Mars disguised
as a diogenite (Meteoritics 29-2, 1994, 152-153).

In Meteoritics (29), 214-221 (1994), David Mittlefehldt wrote in the
introduction to "ALH84001, a cumulate orthopyroxenite member of the
martian meteorite clan":

"In this paper, I report the unmasking of an unusual meteorite related
to the SNC clan that had been masquerading as a diogenite in the
Antarctic meteorite collection since 1985: ALH 84001."


Best wishes,

Bernd
Received on Mon 04 Jun 2001 01:40:57 PM PDT