[meteorite-list] Tafassasset classification

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 10:06:54 2004
Message-ID: <3D9B27CD.C772B489_at_lehrer.uni-karlsruhe.de>

Svend wrote:

> J. Zipfel from the MPI in Mainz says that refractory lithophiles
> fractionated compared to a typical CR composition is leading to
> a possible classification as primitive achondrite. Does anybody
> know about a final classification yet?


Hello Anne, Svend and List,

In the Abstract issue of MAPS (vol. 37-7, July 2002, p. A155),
Jutta Zipfel et al. published an abstract re: Tafassasset. In the
discussion part, the authors state:

The figure illustrates that both samples have compositions clearly
fractionated from CI and other chondrite groups. Tafassasset has AI/Mg
and Mn/Mg ratios similar to other primitve achondrites, indicating
incipient partial melting involving mobilization of SiO2 (+/- A1203,
CaO, etc.) -, P205- and S-rich melts. Although the bulk compositions
are heterogeneous, characteristic element signatures (e.g., low Zn,
Mn/Mg,depletion in refractory lithophile elements) e x c l u d e
a relationship to CR chondrites and support pairing of Taf-Pa and
Taf-Frei*.

* Taf-Pa is the Paris material - Taf-Frei the Freiburg material


Cheers,

Bernd
Received on Wed 02 Oct 2002 01:07:25 PM PDT