Bibcode
Mittlefehldt, D. W.; Lindstrom, D. J.; Lindstrom, M. M.; Martinez, R. R.
Referencia bibliográfica
Conference Paper, 28th Annual Lunar and Planetary Science Conference, p. 961.
Fecha de publicación:
3
1997
Número de citas
4
Número de citas referidas
3
Descripción
Martian meteorite EETA79001 is composed of two distinct magmatic
lithologies, astutely named A and B, joined by an igneous contact.
Lithology B is a coarse-grained, ferroan basalt, while lithology A is
both finer-grained and more magnesian. In addition, lithology A contains
xenocrysts and xenoliths of olivine, orthopyroxene and chromite, which
are petrologically similar to the major phases in Martian lherzolites
such as ALHA77005. A petrologic model to explain the petrographic and
major element composition of lithology A is that it is a mixed magma
composed of basalt like lithology B with a magma similar in composition
to the Martian lherzolites. We have refined this magma-mixing model for
lithology by folding trace element data into the mixing calculations. We
have performed micro-INAA on xenocryst-free groundmass samples drilled
from thin section, and have begun petrologic and geochemical studies of
additional samples of EETA79001, including xenocryst samples, and
ALHA77005. We concur that lithology A is a mixed lithology, but we
believe that it is an impact melt. Lithology B is a large basalt
xenolith in the impact melt.