[meteorite-list] RE: NWA 998

From: Treiman, Allan <Treiman_at_meteoritecentral.com>
Date: Thu Apr 22 10:04:48 2004
Message-ID: <9CBE44BF7DE9D511960300500424D7D0112225_at_cassnt2>

Hi, All --=20

    Ankerite is the mineral name for the iron-bearing
equivalent of dolomite. Dolomite is CaMg(CO3)2, and=20
ankerite is CaFe(CO3)2. Ankerite is incidental to the=20
life-in-ALH84001 fuss -- it has now centered on the=20
itty bitty magnetites in the carbonate globules. Other
parts of the globules contain ankerite carbonate, but
the ankerite was never a big deal in McKay's hypotheses.

   The ankerite is most likely Martian in origin, because
it requires low-oxygen conditions (reducing) to form, unlike
Earth's atmosphere. So, like the carbonate minerals in=20
ALH84001 and in Nakhla, it suggests that liquid water containing
carbonate circulated underground on Mars. But I'm guessing=20
here, as I haven't seen NWA 998.=20

   Allan=20
=20

Allan H. Treiman
Lunar and Planetary Institute
3600 Bay Area Boulevard
Houston TX 77058-1113
   281-486-2117
   281-486-2162 FAX
  treiman_at_lpi.usra.edu


-----Original Message-----
From: Michael Blood [mailto:mlblood_at_cox.net]
Sent: Saturday, May 11, 2002 1:44 PM
To: Treiman, Allan
Cc: Meteorite Mailing List
Subject: NWA 998


Hi Allan & anyone out there who may know,
        I have noticed that the term "ankeritic carbonate" was used=20
in the preliminary Meteoritical Bulletin=A0write-up for NWA 998 =
Nakhlite.=A0
This term was also used in the description of ALH84001.=A0
        Does the term "ankeritic carbonate" mean the=20
same as when the term was used in conjunction with=20
ALH 84001? (if you do a search on yahoo for "ankeritic carbonate"
meteorite the only hit is ALH 84001)
        Does this mean that NWA 998 has the same characteristics=20
as ALH84001 in regards to the possibility of life on Mars controversy?
Received on Mon 13 May 2002 09:27:25 AM PDT