THE METEORITICAL BULLETIN 84-1
                            June 2, 2000
          Jeffrey N. Grossman, Editor (jgrossman@usgs.gov)

           Meteoritical Bulletin, No. 84, 2000 August

Dar al Gani 670          exact location unknown
   Libya
   Found 1999
   Martian basalt (shergottite)
A dark-brown stone, broken into three adjoining pieces, with a total
mass of 1619 g, was found in the Dar al Gani region. Mineralogy and
classification (L. Folco, MNA-SI): cm-sized patches of fusion crust
are present on the external surfaces; porphyritic texture consisting
of mm-sized phenocrysts of brown olivine (Fo58-80) set in a fine
grained basaltic groundmass of tabular pyroxene and interstitial
feldspathic glass (An52-72Or0-1); pyroxene is primarily pigeonite
(En56-66Wo9-13) with subordinate enstatite (En73-82Wo2-3) and augite
(En48-50Wo31-36); other minerals are chromite, titanian chromite,
ilmenite, merrillite and pyrrhotite; shock features include strong
mosaicism and planar deformation in olivine, undulose extinction and
twinning in pyroxene, and abundant impact melt pockets and veinlets;
pervasive veins filled in by calcite are due to terrestrial weathering.
Oxygen isotopes (A. Sexton and I. A. Franchi, OU): d17O = +2.83 \211,
d18O = +4.95 \211, D17O  = +0.26 \211. The petrography and level of
terrestrial weathering are essentially identical to those of DaG 476
and DaG 489, and the three are very likely paired. Specimens: main
mass with anonymous finder; 11.9 g and one polished thin section at
MNA-SI.

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