[meteorite-list] Ibitira and the HED parent body Vesta (?)

From: bernd.pauli_at_paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: Sun Oct 16 16:04:45 2005
Message-ID: <DIIE.0000002900003E11_at_paulinet.de>

Hello Ibitirarians, Eucritarians and Listoids :-)

Ibitira is a basaltic eucrite, and, like all the other eucrites, was believed
to have come from the HED parent body, the asteroid 4 Vesta, but ...

according to an article by D.W. Mittlefehldt in MAPS 40-5, 2005, pp.665-677,
there are (at least) 5 differentiated parent asteroids for the eucrites in our
collections:

1. the HED parent body
2. the mesosiderite parent body
3. the angrite parent body
4. the NWA 011 parent body
5. the Ibitira parent body

How does he know? Because there are differences in certain elemental ratios, oxygen
isotopic compositions, alkali element contents. The differences are subtle but distinct.

Reference:

D.W. MITTLEFEHLDT (2005) Ibitira, a basaltic achondrite from a
distinct parent asteroid and implications for the DAWN mission
(MAPS 40-5, 2005, pp.665-677).

Best wishes
from Bernd, ...

.. happy owner of 43 eucrites and 4 eucrite thin sections, among these, an Ibitira thin
section from Cap'n Blood and a small but beautiful 0.21-gram partslice from M. Cottingham.
Under crossed polars, Ibitira is a sparkling fireworks of colorful pyroxenes (pigeonite and
augite), white plagioclase (An95 = almost pure anorthite), trydimite and ilmenite grains.

My 0.21-gram partslice shows several of those vesicles that Ibitira is famous for.
Received on Sun 16 Oct 2005 04:04:43 PM PDT