[meteorite-list] Re: The Most Expensive Meteorite Ever Sold on eBay (Zagami Mars Meteorite)

From: bernd.pauli_at_paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 10:16:33 2004
Message-ID: <DIIE.0000005F00000DCB_at_paulinet.de>

Hi Ron and List,

> The largest known specimen in circulation (188 grams) of the
> famous Mars rock Zagami, is owned by a private individual ...

Wrong. Bob Haag owns a 2.35-kilo endcut (see Bob's 2003
Collection Catalogue, p. 49).

> ... your chance to own a rare 1.3 Billion
> year old piece of the Red Planet!

Ron responded:

> Zagami is a shergottite, which is 180 million years old. Nakhilites,
> another type of Mars meteorite, are 1.3 billion years old.

Their reference was obviously:

McSWEEN H.Y., Jr. (1994) What we have learned about Mars from SNC
meteorites (Inv.Rev. in Meteoritics 29-6, 1994 November, pp. 757-779).

On p. 762, the author wrote: "The timing of crystallization of the basaltic and
lherzolitic shergottites has been a very controversial subject. The Sm-Nd
whole-rock data fall along an isotopic array ... of about 1.3 Ga. The Rb-Sr
data for mineral separates from the basalts form an isochron of 180 =B1 20 Ma.
.. Shih et al.(1982) and Wooden et al. (1982) interpreted the 1.3-Ga age as
the time of crystallization and assumed that the 180-Ma age represents the
time of shock metamorphism that affected all shergottites."

BUT on page 9 of:

McSWEEN H.Y. Jr. (2002) The Leonard Medal Address: The rocks
of Mars, from far and near (MAPS 37-1, 2002, pp. 007-025)

where the author states:

"The nakhlites and Chassigny crystallized about 1.3 Ga ago,
and the shergottites span an interval from 165 to 875 Ma with
most samples clustering near the recent end of this range."

Yet, the author again cautions in his following statement:

"The young ages of shergottites remain controversial."

Best regards,

Bernd

To: baalke_at_zagami.jpl.nasa.gov
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Received on Thu 14 Aug 2003 01:23:07 PM PDT